Programmable Self-Assembly of Traditional Chinese Medicine (TCM) Monomers: From Molecular Mechanisms to Multifunctional Nanomedicine

Abstract

Self-assembled nanosystems based on non-covalent interactions of traditional Chinese medicine (TCM) monomers have attracted extensive attention in drug delivery. In direct carrier-free systems, the active molecules also serve as building units. These systems may reduce the need for extra carriers and provide high drug loading. Hybrid systems may instead depend on polymers, ions, membranes, or other added materials. This review follows a molecular structure–assembly–property–function chain. Molecular features and environmental conditions guide the assembly pathway. The pathway produces structures such as nanoparticles, fibers, ribbons, and hydrogels. These structures have different sizes, shapes, surface properties, stability, mechanical properties, and responses. These properties can then affect drug release, cellular uptake, tissue retention, targeting, and treatment outcomes. Co-assembly adds another level of control. Component identity and component ratio can change molecular interactions, morphology, and function. The review separates control shown under tested conditions from full programmable design. Most reported systems are controllable only under tested conditions. Few studies have reached full programmable design. This review summarizes molecular rules, control factors, co-assembly modes, and characterization methods. It also discusses applications in druggability, disease treatment, targeted delivery, tissue repair, and theranostics. The review compares direct monomer assembly with polymer-, ion-, membrane-, and carrier-assisted systems. It also discusses reproducibility, biological stability, safety, scale-up, and regulation. The review aims to support more reproducible and predictable design of TCM-derived nanomedicines.

Introduction

Traditional Chinese Medicine (TCM) remains an important therapeutic practice. However, its integration into modern drug development is limited by the complex composition of herbal formulas, unclear mechanisms of action, and the poor solubility or low bioavailability of some active compounds.¹

Studies of several TCM decoctions have identified naturally formed particles or molecular associations. Some isolated assemblies contain active compounds and show biological activity. These findings suggest that self-assembly may represent one physical form of the material basis in selected formulations.² However, current evidence does not show that self-assembly is a universal or sole mechanism of TCM efficacy. Its contribution should be evaluated against free components, unassembled mixtures, and the original decoction.^3,4 Decoction, herb compatibility, and processing can change chemical composition, physical state, dissolution, and biological exposure. Supramolecular chemistry provides a testable framework for studying whether molecular association contributes to these changes. It may help explain selected cases of component cooperation, altered absorption, or reduced toxicity.^5–7

Recent studies have also examined the self-assembly of individual bioactive compounds derived from TCM. Alkaloids, terpenoids, anthraquinones, and flavonoids can form nanoscale structures through hydrogen bonding, hydrophobic effects, electrostatic interactions, and other non-covalent forces.^8,9 However, spontaneous assembly has clear limits. Small changes in concentration, component ratio, pH, solvent, temperature, or preparation history may produce particles, fibers, gels, precipitates, or mixed structures. Many studies report only successful conditions. Few studies report failed conditions, test new molecular pairs, or assess independent batches and stability in biological media.

These limits show the need to distinguish controllable assembly from programmable assembly. A controllable system gives a reproducible and measurable response to a defined input within a tested range. A programmable system requires a target structure or function to be defined before the experiment. It also requires a supported input–output relationship and validation in independent samples or batches. In this review, self-assembly refers to one chemically defined building block forming a structure through non-covalent interactions. Co-assembly refers to two or more chemically distinct components jointly forming the same structure. Aggregation refers to non-specific association when ordered packing or a defined assembly pathway has not been established.

Current studies on TCM monomer self-assembly remain fragmented. They do not yet provide a complete link between molecular structure, assembly regulation, supramolecular architecture, and biological function.^10,11 This review therefore focuses on structurally defined TCM monomers. It examines molecular and environmental control of self-assembly and co-assembly. It also discusses characterization, structure-dependent properties, biomedical applications, evidence limits, and current challenges. This framework aims to support more reproducible and predictable design of TCM-derived self-assembled systems (Figure 1).

Figure 1.

Conceptual framework of controllable self-assembly and co-assembly of TCM monomers. (A) Molecular structural features and environmental factors that regulate assembly. (B) Basic process from TCM-derived compounds to self-assembled structures. (C) Major co-assembly systems involving chemical drugs, polymers, biomacromolecules, biomaterials, inorganic components, and multiple active components. (D) Characterization methods and biomedical applications. (E) Current challenges and future research priorities. (Created with BioRender.com).

Self-Assembly Controllability

This section examines how molecular structure and environmental conditions regulate the self-assembly of TCM-derived monomers. It focuses on the relationships among intermolecular interactions, molecular features, assembly conditions, and structural outcomes.

Molecular Structure–Assembly Relationships

Chemical structure defines possible assembly pathways but rarely determines morphology alone. Amphiphilic balance, aromatic stacking, hydrogen bonding, ionization, rigidity, flexibility, and chirality influence packing, while concentration, component ratio, pH, solvent, temperature, and time can redirect assembly. Nanoparticles, fibers, ribbons, and gels therefore arise from interacting molecular and environmental variables rather than a single functional group.^10,11

Compact amphiphiles often favor finite particles, whereas anisotropic molecules with extended aromatic surfaces and aligned hydrogen-bonding sites may form fibers or ribbons. Molecules with multiple interaction sites can generate hydrogels above a critical concentration. These are conditional trends: the same molecule may form particles, fibers, gels, or precipitates under different conditions.^10,11

Amphiphilicity

Amphiphilic balance is one useful design axis. A hydrophobic face can drive association in water, while polar groups can keep the assembly dispersed. However, a simple hydrophilic–lipophilic label does not predict morphology, as concentration, molecular shape, and the position of polar groups also matter.¹² The catechin–phenylenebisboronic acid (PBA)–isoguanosine (isoG) hydrogel provides a hybrid example.¹³ In this system, PBA acts as a bifunctional connector to form dynamic phenylboronate ester bonds, whereas catechin contributes as an active network component. Nevertheless, catechin alone does not form the reported scaffold. The system therefore represents controlled hybrid co-assembly rather than single-component TCM-derived self-assembly. More broadly, current studies on amphiphilicity-driven assembly rely primarily on qualitative observations, and the absence of quantitative frameworks severely limits predictability across different molecular scaffolds. Future efforts should establish quantitative structure–property relationships to move from trial-and-error observation toward true rational design.

Planar Rigidity and Aromatic Conjugation

Molecular planarity and rigidity can influence molecular packing in self-assembled structures. Triterpenoids and steroids contain rigid hydrophobic skeletons, while anthraquinones and some alkaloids contain planar aromatic regions. These features may support directional packing and aromatic interactions. However, rigidity alone does not predict morphology or stability. Solubility, functional-group position, ionization, concentration, and solvent conditions also affect the final structure.^14,15

Aromatic stacking often works together with other non-covalent forces. Zheng et al proposed a structural model for rhein (Rh) self-assembly. In this model, Rh and Rh sodium salt formed dimers through π–π stacking and hydrogen bonding. The dimers then formed higher-order aggregates and grew into nanofibers.¹⁶ Lin et al compared two binary systems that shared coptisine as one component. Rh–coptisine formed nanofibers, whereas emodin–coptisine formed nanoparticles of about 50 nm (Figure 2).¹⁷ This matched comparison links the structure of the anthraquinone partner to morphology within this specific chemical set. However, it does not establish a general rule for all aromatic TCM molecules. In the Rh system, changes in pH and carboxyl-group deprotonation produced long fibers, short ribbon-like structures, or precipitates.¹⁶

Figure 2.

Representative structure-dependent assembly behaviors of TCM-derived small molecules. Copyright 2023, American Chemical Society.¹⁷

Functional Groups and Intermolecular Interactions

Hydroxyl, carboxyl, amine, and carbonyl groups can provide hydrogen-bond or ionic contact sites. Their number is not enough to predict assembly. Their position, exposure, and geometry also matter.¹⁸ Peng et al studied zingibroside R1 (ZR1), a structurally defined saponin derived from Panax notoginseng. ZR1 spontaneously self-assembled into a hydrogel composed of helical nanofibrils. Cryogenic electron microscopy (cryo-EM) revealed an intricate hydrogen-bonding network within the nanofibrils. The nanofibrils also showed a hydrophobic core and a hydrophilic outer surface.¹⁹ These findings link the spatial arrangement of polar and nonpolar regions to ZR1 packing and nanofibril growth. This study supports a structure-specific assembly mechanism for ZR1. However, it does not establish a general rule for other TCM monomers.

Ionizable groups link molecular structure to pH response. A change in protonation can alter charge, solubility, counterion binding, and hydrogen bonding. The outcome depends on pKa values, local pH, ionic strength, and concentration. The same pH change can yield a dispersed assembly, a new morphology, or precipitation. For this reason, a paper should report the tested pH range and the relevant pKa values when they are known.²⁰

Chirality and Stereoconfiguration

Chiral components are commonly found in TCM. During decoction or preparation, the chiral compounds often self-assemble into nano- or micrometer-scale structures through non-covalent bonding, leading to the appearance of supramolecular chirality and further affecting bioactivity.²¹ Lu et al compared two ellagitannin epimers that differ at one anomeric center. β-D-pentagalloylglucose (β-D-PGG) formed a nanofibrous hydrogel without chemical changes, but α-D-pentagalloylglucose (α-D-PGG) did not gel.²² The authors linked this difference to the positions of aromatic rings and phenolic hydroxyl groups. They also found greater steric hindrance in α-D-PGG. This study shows that one stereochemical change can turn assembly on or off. However, other molecular systems have not yet confirmed this rule.

A study of ephedrine and pseudoephedrine also found different conformations and aromatic contacts during nanoporous material formation.²³ This study supports the same general idea. However, it did not study a carrier-free TCM nanomedicine.

Not every shape difference comes from chirality. Baicalin and wogonoside differ in substituent position. Li et al reported berberine–baicalin nanoparticles and berberine–wogonoside nanofibers.²⁴ This result links molecular structure with packing and morphology. However, it does not show an enantiomer or diastereomer effect.

One TCM-related study used 9-fluorenylmethoxycarbonyl-protected L-tyrosine (Fmoc-L-Y) and its D-enantiomer (Fmoc-D-Y) as chiral templates for achiral berberine (BBR). The authors used 34.7 mM Fmoc-Y and a 29:1 Fmoc-Y/BBR molar ratio. The two enantiomers formed nanofibers with opposite handedness. Under the tested conditions, the right-handed fibers showed stronger bacterial binding, penetration, and photodynamic antibacterial activity.²¹ This system links molecular chirality with fiber handedness and biological function. However, Fmoc-Y is an added amino acid derivative. The system is therefore a chiral hybrid co-assembly, not direct self-assembly of berberine.

Current evidence for chirality remains limited. Most studies do not compare matched enantiomers under the same concentration, ratio, pH, and ionic strength. Few studies test whether handedness remains stable in serum or in vivo. Future studies should use enantiomer pairs, racemic controls, circular dichroism, microscopy, solution methods, and molecular simulation. They should also compare uptake and activity at the same drug dose. These tests can show whether chirality causes the biological effect or only follows another structural change.

Molar Ratio

Component ratio can influence the composition, morphology, and stability of TCM-derived co-assembled structures. Lu et al²⁵ screened baicalein and celastrol at several ratios. The 1:2 ratio gave the smallest and most uniform particles under the reported conditions. Other ratios gave larger or broader distributions. Chang et al reported a second type of ratio control in a berberine–chlorogenic acid system. The authors changed the feed ratio from 1:1 to 1:4. The assembled products retained controlled and consistent component proportions across this range.²⁶ This result supports quantitative control of assembly composition, not only control of particle size. Both studies show that ratio can define a measurable formulation window. However, neither study predicted a ratio rule for a new molecular pair.

Collectively, these findings indicate that molecular structure, stereochemistry, functional-group distribution, and component ratio can jointly regulate assembly behavior and may influence the functional performance of the resulting structures. However, no general rule can yet predict whether a TCM molecule will form particles, fibers, ribbons, or gels. A reliable rule must predict results before testing. The rule must also work with new molecules, ratios, and batches. Studies should report negative results because they show the limits of each rule.²⁷

Competitive and Cooperative Effects of Multiple Interactions

The self-assembly and co-assembly of TCM-derived molecules are generally governed by the cooperative or competitive contributions of multiple non-covalent interactions rather than by a single isolated force. Studies of TCM-derived binary systems have shown that electrostatic interactions, hydrogen bonding, and π–π stacking can jointly contribute to structural formation, whereas detailed analysis of model assemblies suggests that strong π–π stacking may be assisted by weaker hydrogen bonding to generate cooperative assembly behavior.^17,28 Environmental regulation can further rebalance these interactions. For example, pH modulates the balance of multiple non-covalent interactions in herpetrione (Her)–Herpetospermum caudigerum Wall. polysaccharide (HCWP) nanoparticles, affecting their key physicochemical properties.²⁰ Moreover, aromatic stacking alone does not guarantee stable aqueous assembly, because hydrophilicity and functional-group distribution determine whether molecules form dispersed nanoparticles or undergo precipitation.^20,29

Regulation and Influence of Environmental Factors on the Self-Assembly Behavior of TCM Monomers

While molecular structure contributes to the intrinsic assembly propensity of TCM monomers, the observed assembly outcome is also influenced by environmental factors. The self-assembly of TCM monomers is a complex process, and the resulting structures and their stability are sensitive to a range of environmental conditions such as pH, solvent polarity, temperature, and time.^10,30 Controlling these factors may help optimize selected formulations and improve the bioavailability of some active components.¹⁸ Although environmental factors critically influence self-assembly behavior, their synergistic effects remain poorly understood due to the lack of systematic multi-parameter studies. Future research should employ high-throughput screening and machine learning techniques to map self-assembly characteristics under multi-parameter control.

pH

pH is an important factor that influences the self-assembly of monomeric compounds obtained from TCM by adjusting the electrostatic interactions between molecules.²⁰ Changes in pH affect the ionization state of the functional groups as well as the redistribution of charges in the molecules. In the reported Her–HCWP system, increasing pH altered molecular ionization and rebalanced the contributions of electrostatic interactions, hydrogen bonding, and hydrophobic effects. These changes were associated with particle size, surface charge, morphology, and thermal stability. This interaction hierarchy was specific to the tested formulation and should not be generalized to other TCM-derived molecules.¹⁸ Zhu et al employed a pH-driven strategy and found that with increasing pH, Her–HCWP self-assembled nanoparticles (SAN) showed decreased dimensions, increased zeta potential, a more regular morphology, and increased thermal stability (Figure 3).²⁰ Isothermal titration calorimetry (ITC) and chemical perturbation tests supported roles for hydrophobic, hydrogen-bond, and electrostatic effects, and ΔG stayed below zero in the tested range. These data define an alkaline operating window for this system, but they do not show that higher pH will improve the assembly of other TCM molecules.

Figure 3.

(A) Schematic illustration of the formation of Her–HCWP SAN by pH-driven method. (B) Chemical structure of Her. (C) The size distribution of Her–HCWP SAN. Effects of different pH drives on (D) particle size, PDI and (E) zeta potential of Her–HCWP SAN. *P < 0.05, ***P < 0.001, ****P < 0.0001 compared with the pH 11.5 group. Results are shown as mean ± standard deviation (SD) (n = 3). Copyright 2025, Elsevier.²⁰

Solvent Polarity

Solvent polarity modulates both hydrophobic interactions and hydrogen bonding.^18,31 In aqueous media, hydrophobic molecules tend to self-assemble to minimize unfavorable contacts with water. As solvent polarity decreases, hydrophobic interactions weaken, potentially altering the assembly morphology or even causing precipitation. In addition, polar solvents can compete for hydrogen-bonding sites, thereby disrupting solute–solute interactions and further changing the assembly outcome.^30,31

β-sitosterol isolated from Arisaema heterophyllum Blume underwent self-assembly to form a gel, whose network morphology depended strongly on solvent polarity. Specifically, β-sitosterol gels showed different morphologies in different solvents such as banded structures in methanol, layered structures in dimethyl sulfoxide (DMSO), and nanofibers in cyclohexane.³² This result shows strong solvent dependence in one natural product system. It does not prove that dielectric constant alone caused the shape change, because solubility and solvent-specific hydrogen bonding also changed. A solvent study should therefore report solvent identity, water fraction when used, concentration, and mixing order.

Temperature

Temperature is an important factor affecting the equilibrium of non-covalent interactions during self-assembly, and is closely related to the initiation of molecular assembly, structural transitions, and the morphology and function of the resulting systems.^33,34 The decoction process of TCM is inherently thermal, accelerating the dissolution of drug molecules and enhancing their intermolecular contacts, thereby influencing self-assembly via non-covalent forces and ultimately affecting drug efficacy.³⁵

Increasing temperature usually weakens hydrogen bonds. It can also alter hydrophobic hydration, molecular motion, and packing and may therefore promote or disrupt assembly depending on the system.³⁶ In aromatic compounds, temperature can also modify π–π interactions by changing molecular motion, conformation, and stacking geometry.³³

Dong et al prepared an epigallocatechin gallate (EGCG)–stevioside hydrogel with 2.0 M EGCG and 2.5 M stevioside in 2 mL water. The mixture was heated at 80 °C for about 18 h and then cooled to room temperature.³⁷ The hydrogel became a slow-flowing viscous material at 90 °C and recovered after cooling to 25 °C. The authors also used temperature-dependent rheology. This experiment supports reversible thermal control in that formulation. Huang et al reported a second thermal example with berberine and baicalin. The physical mixture formed nanofibers, whereas co-decoction produced nanospheres. The main chemical profiles remained similar. This result reduced the likelihood that new major compounds caused the shape change. The nanospheres also showed stronger antibacterial activity in that study.³⁸ This comparison links thermal history to architecture and function in one matched system. The high concentrations and long heating step in the EGCG–stevioside system limit direct transfer to other systems.

Time

Time influences both the kinetics and equilibrium of assembly. Preparation time can therefore affect the extent of self-assembly and the stability of the resulting nanostructures.¹⁸ Liang et al changed the co-decoction time for Astragalus membranaceus–Angelica sinensis nanoparticles. The mean size was 188.93 ± 2.18 nm at 60 min, 254.52 ± 8.95 nm at 90 min, and 279.77 ± 3.74 nm at 120 min. Polydispersity index (PDI) values rose above 0.3 after more than 90 min.³⁹ Thus, longer heating did not improve the assembly. It promoted larger and less uniform particles. This result defines a process window for one herb pair. It also shows why studies should report heating time, sampling time, cooling, and storage before measurement. These data further indicate that the system operates within a restricted kinetic window, beyond which controlled structural formation may shift toward uncontrolled aggregation.

Other Factors

TCM monomer self-assembly depends on many factors. Researchers can control this process by choosing suitable co-assembly partners, adjusting solution conditions, and applying physical methods. These strategies provide a framework for forming TCM nanoparticles with controlled structure, function, and response. Several factors can change at once. pH can alter charge, hydrogen bonding, and solubility. Temperature can alter dissolution and kinetics. Salt can screen charge and change hydration. Thus, one-factor-at-a-time tests do not reveal factor interactions. Factorial designs should vary at least two inputs and report interaction terms. High-throughput studies can map useful regions, but the model must then be tested with new samples.²⁷

The interplay of multiple factors can also be harnessed for structural engineering. The addition of calcium ions regulated multilevel co-assembly by forming inorganic skeletons, promoting ion bridging and crystal nucleation, and providing gel templates, yielding uniform organic-inorganic hybrid particles with controlled morphologies and tailored functions.⁴⁰ This example illustrates that combinations of ionic and matrix-derived inputs can influence assembly pathways, but the specific conditions and components limit direct transfer to other systems.

Biological media add more variables. Gastrointestinal pH, enzymes, bile salts, dietary lipids, proteins, and ions can change or replace a prepared assembly.⁴¹ A structure made during decoction may not remain intact after administration. Studies should therefore measure the intact assembly and released components at set times. They should not infer in vivo behavior from storage stability alone.

Further studies are needed to understand the microscopic mechanisms of the self-assembly of TCM monomers under the synergistic action of multiple factors. In addition, quantitative reporting should match the tested factor. A pH study should report a response curve across a defined range. A solvent study should report exact composition and water fraction. A temperature study should report transition temperature, heating and cooling rates, hysteresis, G′, and G″. A time study should report the full preparation and measurement timeline. All studies should report replicate number and batch number. These data can support control. Prospective tests in new systems are still needed before a rule is called predictive.

Structure–Assembly–Property–Function Relationships

The biological performance of TCM-derived self-assembled systems is not determined solely by the pharmacological activities of their molecular components. Higher-order organization can modify particle size, morphology, surface characteristics, colloidal stability, and stimulus responsiveness, which may further influence cellular uptake, circulation, tissue distribution, and drug release.^18,42,43 In selected systems, assembly-dependent properties such as chirality and elasticity can additionally regulate interfacial interactions, intracellular trafficking, and tissue penetration.⁴⁴ Consequently, a mechanistic interpretation of TCM-derived self-assembly should clarify how defined molecular structures or environmental conditions regulate the assembly pathway and resulting nanostructure, how these structural changes determine physicochemical properties, and how the resulting properties ultimately influence biological functions.

The oleanolic acid (OA) system illustrates how mechanical properties may link assembly structure with biological behavior. Antiparallel packing produced rigid nanoparticles and flexible nanogels. The flexible nanogels showed lower cellular uptake than the rigid particles, but they showed better lysosomal escape and deeper tumor penetration. They also reduced collagen and increased immune-cell infiltration by about eight- to tenfold in the reported tumor model.⁴⁴ This study links packing, elasticity, trafficking, and function. It provides a strong structure–function model, although the relationship has not been prospectively validated across other molecular scaffolds. Together with the stereochemical and ratio-control studies above, this work shows that TCM-related assemblies already have several defined design levers. The main limitation is the transfer of those levers beyond one chemical family, not the absence of controllability itself.

Co-Assembly Strategies and Multifunctional Applications

Single-component TCM-derived self-assembly establishes the basic relationship between molecular structure and assembled architecture. Controllable self-assembly adds environmental or formulation inputs to regulate structural outcomes. Co-assembly further expands this design space by introducing chemically distinct components with complementary structural and functional roles, potentially integrating pharmacological activity, structural stabilization, responsiveness, targeting, and therapeutic synergy within one nanosystem. However, adding multiple components does not make a system programmable by itself. Studies must define and test the role of each component (Figure 4).

Figure 4.

Major co-assembly systems involving TCM-derived monomers.

Nevertheless, many reported co-assembled systems remain empirically optimized, and functional enhancement may reflect simple pharmacological combination rather than the emergence of assembly-dependent properties. A mechanistically informative co-assembly system should clarify the structural role of each component, the hierarchy of intermolecular interactions, the resulting architecture, and the specific contribution of that architecture to biological performance.

Co-Assembly of TCM Monomers and Chemical Drugs

Co-assembly between TCM monomers and conventional chemical drugs provides a strategy for integrating complementary pharmacological activities with material-forming functions while addressing some of the limitations of single-agent systems. In carrier-free co-assembled systems, both components may participate directly in nanostructure formation while retaining their respective biological activities. This functional convergence can be described as active ingredient–material duality.

Yuan et al fabricated a series of carrier-free natural polyphenol–metformin nanoparticles through the co-assembly of pharmacologically active components. The resulting nanoparticles exhibited pH responsiveness and antioxidative activity. Natural polyphenols contributed to the regulation of the injury-associated microenvironment, whereas metformin provided pro-neurogenic activity. Their complementary functions promoted the differentiation of activated neural stem cells into neurons and oligodendrocytes and improved functional recovery in rats with spinal cord injury (Figure 5).⁴⁵ Because the nanoparticles were constructed exclusively from active components, this system is appropriately regarded as carrier-free active-component co-assembly exhibiting API–material duality.⁴⁵

Figure 5.

A schematic diagram of the fabrication and therapeutic mechanism of polyphenol-metformin NPs for spinal cord injury repair. Copyright 2023, American Chemical Society.⁴⁵

Not all nanosystems combining TCM-derived compounds with conventional drugs are formed through direct co-assembly. Zhao et al⁴⁶ first covalently linked artesunate (ART) and mycophenolate mofetil (MMF) through esterification to generate an amphiphilic ART–MMF prodrug, which subsequently self-assembled in aqueous media. DSPE–PEG2000 was additionally incorporated for surface PEGylation to improve nanoparticle stability and circulation performance, producing PEGylated ART–MMF nanoparticles (AMNPs). Compared with free ART and MMF, AMNPs exhibited enhanced biocompatibility and immunosuppressive activity and prolonged graft survival.⁴⁶ Therefore, this system should be classified as the carrier-assisted self-assembly of a covalent drug conjugate rather than as carrier-free drug–drug co-assembly. The ART–MMF conjugate provides the principal pharmacologically active and self-assembling unit, whereas DSPE–PEG2000 contributes an additional formulation-supporting function.

Collectively, these examples indicate that the convergence between active-ingredient and material-forming roles exists along a continuum that includes pure or carrier-free nanodrugs, carrier-mimicking systems, and self-assembling drug conjugates.⁴⁷ In direct carrier-free co-assembly, as represented by the polyphenol–metformin nanoparticles, pharmacologically active molecules jointly constitute the nanostructure without an additional carrier.⁴⁵ In conjugate-based systems such as the ART–MMF formulation, a newly synthesized prodrug provides the principal self-assembling unit, but auxiliary materials may still be required to achieve sufficient colloidal stability and in vivo performance.^45,46 Transferable rules for component selection, ratio optimization, and structure-dependent biological performance have not yet been established.

Co-Assembly of TCM Monomers and Polymeric Materials

Co-assembly with polymers can incorporate TCM-derived small molecules into functional networks. In these systems, polymers may contribute structural groups, dynamic crosslinks, mechanical properties, and environmental responses. TCM monomers may act as active compounds, interaction sites, or structural regulators. Their exact roles should be tested rather than assumed.

In a polyvinyl alcohol (PVA)–borax–puerarin (BP) hydrogel, borate ions form dynamic crosslinks with both PVA and puerarin. Puerarin participates in network formation rather than simple encapsulation. The system shows a nonlinear dependence on composition, with an optimal formulation (1 wt% borax, 1 wt% puerarin, 5 wt% PVA) giving maximum mechanical strength, while excess puerarin weakens the network (Figure 6).⁴⁸ These results support a finite composition window for the tested hydrogel.

Figure 6.

Schematic diagram of raw materials, production process, and reaction principle required for polyvinyl alcohol (PVA)–borax–puerarin (BP) hydrogel. (A) Raw materials for preparing PVA–BP hydrogel; (B) The apparent characteristics of BP solution and PVA–BP hydrogel; (C) SEM structure of PVA–BP hydrogel. Copyright 2025, MDPI.⁴⁸

Thiolated chitosan–puerarin hydrogels introduce redox-active and pH-sensitive sites through polymer modification. The polymer matrix converts environmental signals into structural rearrangement and controlled release.⁴⁹ Here, responsiveness is not discovered but encoded into the polymer design.

In chiral hydrogels formed from EGCG and L- and D-phenylalanine gelators, further reinforced by PVA and hyaluronic acid, chirality defines supramolecular organization while polymers enhance network stability through multivalent interactions. The system exhibits improved mechanical properties, self-healing, and distinct cellular responses between L- and D-configurations, showing that chirality, composition, and polymer design act as coupled input parameters.⁵⁰

These systems demonstrate a simple but important design logic: polymer structure defines interaction space, composition defines the assembly window, and external stimuli define structural transitions. These structure–property relationships remain specific to the tested polymer compositions and preparation conditions.

Co-Assembly of TCM Monomers and Biomacromolecules

The diverse functional groups of TCM monomers can support co-assembly with biomacromolecules and help generate hybrid functional nanostructures. Li et al⁵¹ demonstrated that salvianolic acid B (SAB) self-assembled into an acidic hydrogel and interacted with fibrin to form a dual network. Structural and spectroscopic results supported contributions from hydrogen bonding, aromatic interactions, and possible electrostatic effects. The hybrid network showed higher mechanical strength and biological activity in the reported tests. However, the study did not isolate the contribution of each interaction or show that the mechanism applies to other biomacromolecules.

Co-Assembly of TCM Monomers and Biomaterials

Beyond regulating nanostructure formation, co-assembly provides an opportunity to integrate structural and functional components within a single nanosystem. The Fmoc-Y/berberine system represents such a strategy, in which Fmoc-Y acts as a chiral structural regulator while berberine contributes pharmacological and photodynamic functions. The resulting nanofibers had opposite handedness. Under the tested conditions, the right-handed fibers showed stronger bacterial interaction, intracellular accumulation, and photodynamic antibacterial activity than the left-handed fibers (Figure 7).²¹ These results link supramolecular handedness with biological behavior in this hybrid system. However, they do not show that the same relationship applies to other chiral assemblies.

Figure 7.

Chiral preference-driven antibacterial performance of Fmoc-Y/BBR co-assembled systems. (A) The chemical structures of Fmoc-Y enantiomers and BBR, and schematic illustration of their co-assembly into helicity-controlled nanofibers. (B) The photodynamic properties of nanofibers, and the differential interaction mechanisms between bacterial membranes and nanofibers with different supramolecular chirality. (C) Comparison of photodynamic bacterial inhibition rates of P-helicity nanofibers and M-helicity nanofibers toward E. coli and S. aureus. *P < 0.05 and **P < 0.01. Copyright 2026, Wiley.²¹

Co-Assembly of TCM Monomers with Inorganic Ions or Materials

Inorganic ions can regulate the assembly of TCM-derived small molecules through coordination, charge modulation, or ionic bridging. Their addition may change network structure, mechanical properties, and stability. However, these effects depend on the ion, molecular components, concentration, and preparation conditions.⁵²

Yu et al recently constructed a multicomponent supramolecular hydrogel through Zn²⁺-modulated co-assembly of glycyrrhizic acid (GA) and Rh, two chemically defined small molecules derived from Chinese medicinal herbs. In this system, Zn²⁺ was not used as a preformed nanocarrier but participated directly in network regulation through complexation. Evidence obtained from isothermal titration calorimetry, zeta-potential analysis, and spectroscopic measurements supported this interpretation. Structurally, the hydrogel comprised a micron-scale network of GA nanofibrils and a submicron network formed by GA–Rh co-assembled nanofibrils. The addition of Zn²⁺ increased the stiffness and toughness of the hydrogel, which also exhibited antibacterial and anti-inflammatory activities in vitro. However, because biological evaluation was limited to in vitro experiments, its in vivo therapeutic relevance, long-term stability and safety remain to be established (Figure 8).⁵³

Figure 8.

A novel multicomponent supramolecular hydrogel system constructed from the co-assembly of glycyrrhizic acid (GA) and Rh via Zn²⁺ modulation exhibits excellent mechanical robustness and desirable biological performance. Copyright 2025, Royal Society of Chemistry.⁵³

The structural role of the inorganic ion differs between the GA–Zn–Rh and Ma-Xing-Shi-Gan decoction (MXSGD)-derived systems. Whereas Zn²⁺ mainly reinforced and reorganized the GA–Rh fibrillar network, Wang et al proposed that Ca²⁺ and pseudoephedrine acted as connectors in a carrier-free quaternary hydrogel containing pseudoephedrine, amygdalin, and GA. GA served as the principal scaffold, while amygdalin contributed to network stabilization. Compared with the original MXSGD decoction and individual constituents, the assembled hydrogel showed stronger antipyretic and anti-inflammatory effects.⁵⁴

These systems show that inorganic ions can change network structure and mechanical properties. However, the reported relationships remain system-specific. Most studies have not established in vivo stability, long-term safety, batch reproducibility, or disassembly behavior.

Multicomponent Co-Assembly

In TCM-derived systems, multicomponent co-assembly can blur the conventional distinction between an active pharmaceutical ingredient (API) and a formulation material. Lei et al integrated catechin, isoG, and PBA to construct the catechin–PBA–isoguanosine hydrogel through dynamic phenylboronate ester bonds. IsoG provides the principal self-assembled scaffold, whereas PBA establishes dynamic crosslinks with the cis-diol-containing components. Catechin is therefore not merely incorporated as a passive therapeutic cargo; it provides pharmacological activity while also participating in the formation of the hydrogel network. The system consequently exhibits API–material duality, in which an active compound contributes to both therapeutic function and material construction.¹³

Notably, current studies often interpret functional enhancement in such systems as a simple additive effect of multiple components. However, a more fundamental mechanism lies in the emergence of new physicochemical and biological properties during co-assembly. At the structural level, co-assembly can generate emergent architectures, such as transformations from nanoparticles to nanofibers, accompanied by increased molecular ordering. At the functional level, emergent behaviors may include enhanced targeting capability, amplified therapeutic synergy, and reduced systemic toxicity. At the dynamic level, co-assembled systems often exhibit altered release kinetics and improved responsiveness to environmental stimuli. These findings suggest that multicomponent co-assembly systems may behave as nonlinear systems. However, they support the possibility of emergent and non-additive behavior only in selected systems; they do not establish a universal “1 + 1 > 2” relationship. Such a conclusion requires direct comparison with individual components, physical mixtures, and deliberately non-assembled formulations.

However, the underlying mechanisms governing multicomponent co-assembly remain poorly understood, which limits the rational design of such systems. Future studies should identify interaction hierarchies and test whether assembly outcomes can be predicted across new component combinations and independent batches.

Characterization Methods of Self-Assembly

Advanced characterization techniques are pivotal in elucidating the formation mechanisms, structural features, and functional properties of self-assembled systems derived from TCM monomers. Far from serving merely as observational tools, these techniques offer critical insights into the hierarchical organization, intermolecular interaction networks, and dynamic evolution of self-assembled and co-assembled structures.⁵⁵ No single analytical technique is sufficient to establish a self-assembly mechanism; mechanistic conclusions require convergent evidence from complementary methods and appropriate controls. Accordingly, characterization should be conceptualized not as a mere collection of isolated methods, but as a mechanism-driven analytical framework.^40,56

Morphological Characterization

Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) provide direct images of particle shape, dimensions, edges, and local organization. These methods can distinguish nanoparticles, fibers, ribbons, sheets, and porous networks. In multicomponent self-assembly systems derived from bioactive TCM molecules, electron microscopy has been widely used to visualize hierarchical morphologies and aggregate architectures.^10,30 However, conventional TEM and SEM often require drying, fixation, staining, or vacuum exposure. These steps may cause soft assemblies to shrink, collapse, fuse, or aggregate, which can lead to deviations from their native hydrated state. Therefore, TEM or SEM images alone cannot establish the true solution-state structure or colloidal behavior of the assembly. When hydrated or dynamic states are important, complementary techniques such as cryogenic electron microscopy, environmental SEM, small-angle X-ray scattering (SAXS), dynamic light scattering (DLS), or nanoparticle tracking analysis (NTA) should be employed to obtain a more reliable structural interpretation.⁵⁷

SAXS measures the average structure of an assembly in solution. It requires less sample preparation than conventional electron microscopy. SAXS can provide information on particle size, internal spacing, structural order, and time-dependent changes. However, SAXS data require model fitting. Different structural models may produce similar scattering curves, especially in polydisperse or multicomponent systems. SAXS also averages all species in the sample and may not detect a small subpopulation. Therefore, SAXS results should be compared with direct imaging, particle-size analysis, and chemical composition data.⁵⁸

Cryo-EM can preserve hydrated soft structures more effectively than conventional dry-state TEM. It can also reveal internal organization. However, freezing, blotting, ice thickness, and electron-beam exposure may still affect the observed structure. Cryo-EM should therefore be regarded as a near-native method rather than an artifact-free method.^57,59 Atomic force microscopy (AFM) can measure surface height, roughness, and local mechanical properties. However, adsorption to the substrate and force from the probe may change soft assemblies. Scanning tunneling microscopy (STM) is useful for surface-bound and conductive assemblies. It does not represent the behavior of freely dispersed structures in bulk solution. Therefore, AFM and STM results should be interpreted within the specific sample environment.^57,58

Size Distribution and Stability

DLS provides a rapid and non-destructive estimate of hydrodynamic diameter in suspension. It is useful for screening particle-size changes during preparation and storage.^60,61 However, DLS does not measure the hydrodynamic diameter of individual particles. Its intensity signal is strongly affected by larger particles. A small amount of dust or a small number of large particle clusters may therefore shift the reported size. DLS also has limited ability to resolve broad or multimodal samples. A narrow peak or a low polydispersity index does not prove that an assembly is morphologically uniform or structurally ordered.^60,62 DLS results should be compared with TEM or cryo-EM and, when possible, with NTA or SAXS.⁶³

Zeta potential reflects the electrophoretic behavior and net surface charge of dispersed particles. It can be used to compare charge changes after assembly or surface treatment. Repeated measurements under the same conditions may also support an assessment of dispersion stability. However, zeta potential does not directly identify surface chemical groups. It cannot by itself confirm successful ligand attachment or a targeting mechanism. The result also depends on pH, ionic strength, conductivity, temperature, and the selected measurement model. Studies should therefore report the measurement medium and combine zeta potential with chemical analysis and time-dependent stability tests.⁵⁹ NTA and resistive pulse sensing (RPS) provide particle-by-particle information and can help resolve heterogeneous samples. However, both methods have detection limits. NTA depends on particle scattering, refractive index, camera settings, and sample concentration. RPS depends on pore size, particle shape, electrolyte conditions, and the risk of pore blockage. These methods can complement DLS, but they should not be described as universally more accurate.⁵⁶

Characterization of Internal Structure and Molecular Interactions

Changes in optical properties can provide preliminary evidence of coordination interactions in TCM-derived self-assembled systems.⁵² Ultraviolet–visible (UV–Vis) spectroscopy can detect changes in the electronic environment, chromophore association, and aggregation state. It is rapid and requires little sample preparation. However, a band shift or intensity change cannot identify a specific π–π stacking or metal-coordination mode.⁶⁴ Fourier-transform infrared spectroscopy (FT-IR) can detect changes in functional-group environments and may support hydrogen bonding or coordination. However, peak shifts may have several causes. They do not define the exact binding site or the contribution of each interaction.³⁹ Proton nuclear magnetic resonance (¹H NMR) can detect local chemical-environment changes through chemical shifts and signal broadening. However, rapid exchange, low solubility, and large assemblies may weaken or broaden the signals. These methods should therefore be combined with ITC, X-ray diffraction (XRD), SAXS, high-resolution mass spectrometry (HR-MS), chemical perturbation tests, or molecular simulation.⁶⁵

XRD can distinguish crystalline and amorphous states. It can also show changes in molecular packing and provide repeat distances when ordered diffraction peaks are present.^58,66 However, a changed diffraction pattern or a new crystalline fingerprint does not alone prove molecular co-assembly. Amorphization, recrystallization, polymorphic transition, or formation of a new crystalline phase may produce similar changes.⁶⁵ XRD should therefore be interpreted with spectroscopy, calorimetry, and solution-state structural methods.

Characterization of Assembly Dynamics, Thermodynamics, and Stability

Differential scanning calorimetry (DSC) detects melting, glass transitions, and other phase changes. A shifted or missing thermal peak may support a change in component state or intermolecular association. However, DSC cannot by itself distinguish co-assembly from amorphization, recrystallization, or physical mixing.⁶⁷ Thermogravimetric analysis (TGA) measures mass loss and decomposition as temperature increases. It is useful for comparing thermal stability and the content of water or volatile components.⁶⁸ However, TGA does not identify the assembly mechanism or predict colloidal stability in water. DSC and TGA should therefore be combined with XRD, spectroscopy, and solution-state stability tests.

Rheology measures the bulk mechanical behavior of gels. Storage modulus, loss modulus, strain sweep, frequency sweep, and recovery tests can define gel formation, stiffness, flow, and self-recovery. These data can support the assessment of injectability and structural retention.^69,70 However, rheology provides an average response of the whole sample. The result depends on the instrument geometry, gap, temperature, loading history, and test range.⁷¹ Rheology cannot show the local nanofibril structure or prove a molecular interaction. It should be combined with microscopy, SAXS, and application-specific retention or release tests.

ITC measures heat released or absorbed during titration. It can estimate enthalpy change, binding constant, and apparent stoichiometry. These parameters provide quantitative evidence of molecular association. However, the fitted values depend on the selected binding model and the accuracy of concentration and heat measurements. Dilution heat, baseline changes, mixing, and other background signals may also affect the results.^72,73 Because ITC provides an integrated thermodynamic signal, it does not directly identify the exact molecular contact site or independently establish which microscopic interaction is dominant. Structural and spectroscopic evidence is therefore still required.

Molecular dynamics (MD) simulations can show possible contact sites, packing modes, and assembly pathways at the atomic scale. However, the results depend on the force field, starting structure, simulation time, ion parameters, and solvent model. MD therefore provides a testable mechanistic model rather than direct proof. The model should be compared with experimental results, such as intermolecular distances, spectra, scattering data, or thermodynamic trends.⁶⁵

Chemical Composition and Structural Identification

High-performance liquid chromatography (HPLC) can quantify selected components when suitable reference standards are available.³⁹ Ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC–HR-MS) can identify or tentatively assign many compounds in complex TCM-derived assemblies. It can also compare component enrichment among the original solution, supernatant, precipitate, and isolated assembly fraction. However, detection of a compound in an isolated fraction does not prove that it is a structural building block. Ionization bias, isomers, adduct formation, and incomplete databases may also affect compound assignment. Composition data should therefore be combined with fractionation, component-depletion, reconstitution, or assembly-perturbation experiments.³⁹

Integrated characterization should form an evidence chain, not a list of methods. Liquid chromatography–mass spectrometry (LC–MS) identifies candidate molecular components associated with the assembly. SEM and TEM show morphology, while DLS estimates hydrodynamic size and dispersion. SEM–Raman spectroscopy links local structure with chemical information.⁴⁰ Spectroscopy, SAXS, and calorimetry provide evidence for molecular interactions, packing, and phase changes. MD simulations can suggest assembly pathways, while SAXS can test the average structural model. Researchers should compare simulation results with experimental data.⁶⁵ No single method can prove an assembly mechanism. Several methods must give consistent results. Time-based tests can show whether a structure is stable, reversible, or responsive. Control tests should also exclude physical mixing, precipitation, recrystallization, and preparation artifacts.

Table 1 summarizes this evidence chain. It links each method with the information that it can support. It also shows how these methods help assess controlled or programmable self-assembly in TCM-derived systems.

Table 1.

Characterization Framework for Evaluating Controllable and Programmable Self-Assembly of TCM Monomers

Characterization Focus	Main Methods	Evidence Provided	Main Limitations	Complementary Evidence	References
Morphology and hydrated structure	TEM, SEM, cryo-EM, AFM, STM	Particle shape, dimensions, surface features, local organization, and hydrated structure	Drying, fixation, staining, vacuum, freezing, substrate adsorption, and probe force may change soft assemblies. Local images may not represent the whole sample	Combine conventional imaging with cryo-EM, SAXS, DLS, or NTA	[57,58]
Size and dispersion in solution	DLS, NTA, RPS, SAXS	Hydrodynamic size, particle number distribution, average solution structure, and aggregation during storage	DLS is sensitive to dust and large aggregates. NTA and RPS have detection limits. SAXS provides an average signal and requires model fitting	Compare an ensemble method with direct imaging or a single-particle method	[56,58,63]
Surface charge and colloidal stability	Zeta potential, time-dependent DLS	Net surface charge, charge changes, aggregation trends, and short-term dispersion stability	Zeta potential does not identify surface chemical groups, ligand attachment, or targeting mechanisms. The result depends on the measurement medium	Report pH, ionic strength, conductivity, temperature, and storage time. Combine with chemical analysis and stability tests	[58,59]
Molecular interactions	UV–Vis, FT-IR, 1H NMR	Changes in the electronic environment, functional-group environment, and local chemical environment	Spectral shifts provide indirect evidence. A single spectrum cannot establish a specific interaction or identify the dominant driving force	Combine spectroscopy with ITC, XRD, SAXS, chemical perturbation tests, or MD simulation	[64,65]
Molecular packing and internal order	XRD, SAXS, cryo-EM	Crystalline or amorphous state, repeat distance, internal order, and average structural model	A changed XRD pattern does not prove co-assembly. SAXS fitting may not be unique. Cryo-EM examines a limited sample area	Compare solid-state, solution-state, and spectroscopic results	[58,65]
Phase and thermal behavior	DSC, TGA	Melting, glass transition, phase change, decomposition, water or volatile content, and thermal stability	Thermal changes cannot independently distinguish co-assembly from physical mixing, amorphization, or recrystallization. TGA does not predict colloidal stability in water	Combine DSC and TGA with XRD, spectroscopy, and solution-state stability tests	[67,68]
Mechanical and recovery properties	Rheology	Storage modulus, loss modulus, gel point, stiffness, flow, yield behavior, and structural recovery	Rheology provides a bulk average. The result depends on instrument geometry, temperature, loading history, and test range. It does not show local nanostructure	Combine rheology with microscopy, SAXS, and retention or release tests	[69–71]
Binding thermodynamics	ITC	Enthalpy change, binding affinity, apparent stoichiometry, and overall thermodynamic trends	The fitted values depend on the binding model, concentration accuracy, dilution heat, baseline, and background signals. ITC does not identify the exact contact site	Combine ITC with spectroscopy, structural analysis, dilution controls, and concentration controls	[72,73]
Chemical composition and spatial distribution	HPLC, LC–MS, UHPLC–HR-MS, SEM–Raman	Component identity, quantitative content, component enrichment, and spatial chemical distribution	Detection of a compound does not prove that it is a structural building block. Ionization bias, isomers, adducts, and database limits may affect identification	Combine composition analysis with fractionation, component removal, reconstitution, or assembly perturbation tests	[39,40]
Mechanistic model and assembly pathway	MD simulation combined with SAXS, NMR, or ITC	Possible contact sites, packing modes, interaction energies, and atomistic assembly pathways	Simulation results depend on the force field, starting structure, simulation time, ion parameters, and solvent model. MD is not direct proof	Validate the model with independent structural, spectroscopic, scattering, or thermodynamic results	[65,67]
Stability, reversibility, and responsiveness	Time-dependent DLS, spectroscopy, SAXS, rheology, microscopy	Changes in size, morphology, molecular association, mechanical behavior, and structural recovery over time or after stimulation	Short observation periods may miss delayed aggregation or disassembly. Signal recovery does not always mean complete structural recovery	Use repeated measurements, independent batches, and stimulus-on/stimulus-off controls	[56,58,63,69–71]

Abbreviations: AFM, atomic force microscopy; cryo-EM, cryogenic electron microscopy; DLS, dynamic light scattering; DSC, differential scanning calorimetry; FT-IR, Fourier-transform infrared spectroscopy; HPLC, high-performance liquid chromatography; ITC, isothermal titration calorimetry; LC–MS, liquid chromatography–mass spectrometry; MD, molecular dynamics; NMR, nuclear magnetic resonance; NTA, nanoparticle tracking analysis; RPS, resistive pulse sensing; SAXS, small-angle X-ray scattering; SEM, scanning electron microscopy; STM, scanning tunneling microscopy; TEM, transmission electron microscopy; TGA, thermogravimetric analysis; UHPLC–HR-MS, ultra-high-performance liquid chromatography–high-resolution mass spectrometry; UV–Vis, ultraviolet–visible spectroscopy; XRD, X-ray diffraction.

Applications in Biomedicine

TCM-derived self-assembled systems have been studied in drug formulation, disease models, targeted delivery, tissue repair, and theranostics. Most available evidence remains preclinical (Figure 9). The biological effects of these systems should be interpreted in relation to their structural and physicochemical properties rather than by disease category alone. Particle size and surface characteristics influence colloidal behavior and interactions with cellular membranes; morphology and aspect ratio can affect intracellular processing, tissue retention, and organ distribution; elasticity and deformability regulate endocytosis, lysosomal escape, and tissue penetration; and structural stability and responsiveness determine whether active components remain associated during circulation and are released at the intended site. These effects are system-dependent and should not be assumed solely from particle morphology. Across these applications, the reported biological benefits should be considered at three levels: the intrinsic pharmacological activity of the components; formulation-level effects arising from altered dispersion, stability, retention, or release; and architecture-dependent effects arising specifically from the assembled state. An outcome can be attributed to self-assembly itself only when dose-matched free-component mixtures, deliberately non-assembled or disassembled controls, and appropriate carrier or formulation controls are included. Most current studies support component- and formulation-level benefits, whereas comparatively few isolate the contribution of the assembled architecture.

Figure 9.

Biomedical applications of TCM-derived self-assembled and co-assembled systems. (A) Applications investigated in tumor, neurological, cardiovascular, inflammatory, infectious, immune-modulation, and tissue-repair models. (B) Active targeting and stimuli-responsive release based on pH, reactive oxygen species, glutathione, and enzymes. (C) Multifunctional platforms combining photodynamic, photothermal, sonodynamic, magnetic-response, imaging, and therapeutic functions. (D) The transformation of TCM-derived active compounds into self-assembled nanomedicines. (Created with BioRender.com).

Enhancement of Druggability for Bioactive Components in TCM

Some TCM-derived compounds have low aqueous solubility or limited environmental stability. The following examples examine whether assembly changes dispersion, exposure, or formulation stability. Celastrol is a bioactive compound isolated from the root bark of Tripterygium wilfordii. However, its biomedical application remains limited due to poor water solubility, low bioavailability, and high toxicity. Similarly, erianin derived from Dendrobium also suffers from poor aqueous solubility. In the celastrol–erianin system, the authors reported increased aqueous dispersion, systemic exposure, and antitumor effects under the tested conditions.⁷⁴ As a characteristic active constituent of Dipsacus asperoides, Asperosaponin VI (ASP VI) can spontaneously form dynamic self-assembled structures in the presence of sodium taurocholate and dipalmitoylphosphatidylcholine upon dissolution in the gastrointestinal tract. This process further promotes its gastrointestinal absorption, increases its in vivo exposure, and ultimately improves the druggability and pharmacological properties of ASP VI.^74,75 These examples illustrate two different routes to improved druggability: direct co-assembly of two active compounds in the celastrol–erianin system, and environmentally induced assembly with endogenous gastrointestinal components in the ASP VI system. Because the formulations, administration contexts, and evaluated endpoints differ, the observed improvements cannot be assigned to a single common assembly mechanism.

Treatment of Diseases

As an important direction in the modernization of TCM, TCM-derived self-assembly has advanced rapidly in therapeutic applications in recent years. The disease-oriented studies below differ in assembly class, administration route, experimental model, and therapeutic endpoint. Therefore, this section compares how the assembled state contributes to delivery or treatment. It does not treat all examples as evidence for one shared therapeutic mechanism. Direct active-component assemblies are separated from polymer-, membrane-, metal-, or carrier-assisted systems whenever the available evidence permits.

Cancer Therapy

Cancer-oriented TCM-derived assemblies can be broadly divided into direct active-component assemblies and carrier-assisted hybrids, which differ in how the nanostructure contributes to treatment. In direct assemblies, structural organization may alter dispersion, component ratio, exposure, or release, whereas in carrier-assisted systems, targeting and cargo delivery may depend substantially on auxiliary materials rather than on the TCM-derived components alone.^76–82 As discussed above, the self-assembled OA system provides evidence that antitumor performance in this specific formulation is influenced not only by molecular composition and particle size but also by nanomechanical properties, because flexible OA nanogels exhibited lower cellular endocytosis than rigid OA nanoparticles while showing enhanced lysosomal escape, deformation-assisted tumor penetration, and improved antitumor efficacy.⁴⁴ This finding challenges the assumption that greater cellular uptake necessarily predicts better in vivo performance.

Neurological and Cerebrovascular Disorders

Neurodegenerative diseases are pathologically characterized by progressive neuronal damage and apoptosis, accompanied by the aggregation of abnormal proteins.⁸³ Current treatments face several challenges, including poor ability of drugs to cross the blood–brain barrier, low drug stability, single-target mechanisms, and limited therapeutic efficacy.^83,84

More direct evidence comes from systems in which TCM-derived small molecules form the therapeutic structure. Luo et al prepared a glycyrrhizic acid–berberine–rhein hydrogel (GBR-gel) under physiological conditions. The system contained no added carrier. The researchers applied the hydrogel directly to the injured brain. GBR-gel reduced inflammation and neural impairment after traumatic brain injury. The authors also linked the response to recovery of the suppressed glutamatergic synapse pathway.⁸⁵

Lou et al used ginsenoside Rg3 and naringenin as both active compounds and building units. The two molecules formed nanoparticles by an antisolvent method. The system contained no polymeric carrier or surfactant. Molecular simulations and FT-IR spectroscopy supported roles for hydrogen bonding and hydrophobic interactions. Intranasal delivery promoted particle accumulation in affected brain regions in an early Alzheimer’s disease mouse model. The system reduced amyloid-β deposition, oxidative stress, and inflammatory signals. It also alleviated cognitive deficits (Figure 10).⁸⁶

Figure 10.

Carrier-free co-assembly, intranasal delivery, and proposed neuroprotective mechanism of ginsenoside Rg3–naringenin nanoparticles (GNNs) in early Alzheimer’s disease. Copyright 2026, MDPI.⁸⁶

These studies represent two distinct direct-assembly strategies: a locally applied multicomponent hydrogel and an intranasally delivered binary nanoparticle. Because they addressed different diseases, administration routes, and endpoints, the available evidence supports only system-specific effects and does not establish a general design rule for neurological or cerebrovascular disorders.

Treatment of Cardiovascular Diseases

Cardiovascular diseases are associated with high incidence, disability, and mortality rates, and their pathogenesis often involves oxidative stress, inflammation, thrombosis, and endothelial injury.⁸⁷ TCM-derived self-assembled systems have been investigated for cardiovascular therapy through endothelial protection and antithrombotic, anti-inflammatory, or antioxidant effects. Ginsenoside Rb1 and probucol first co-assembled into carrier-free ginsenoside Rb1–probucol nanoparticles (RPNPs). Macrophage microvesicles (MMVs) then coated the RPNPs to form MMVs/RPNPs.⁸⁸ The active compounds form the core, while the membrane adds targeting and biological-interface functions. This study therefore supports a hybrid design. It does not isolate the effect of the co-assembled core from the effect of membrane coating. Causal attribution requires comparisons among dose-matched free drugs, uncoated RPNPs, and suitable membrane controls.

Treatment of Inflammatory Diseases

Inflammatory diseases encompass a wide spectrum of disorders, including rheumatoid arthritis, ulcerative colitis, pneumonia, and psoriasis, whose pathogenesis essentially involves excessive inflammatory responses triggered by aberrant immune activation. The reported inflammatory systems do not operate through one shared mechanism, but intervene at different stages of disease-specific inflammatory processes. The sinomenine–glycyrrhizic acid nanohydrogel was associated mainly with the regulation of excessive neutrophil activation and nuclear factor kappa B (NF-κB)/mitogen-activated protein kinase (MAPK) signaling in rheumatoid arthritis,⁸⁹ whereas Coptidis Rhizoma self-assembled nanoparticles ameliorated inflammatory damage in an atopic dermatitis model and berberine–hesperetin nanoparticles combined immune-microenvironment regulation with intestinal-barrier repair in ulcerative colitis.^90,91 By contrast, the baicalin–resveratrol system incorporated an additional antiviral function in respiratory syncytial virus-induced pneumonia.⁹² Direct comparison among these systems remains inappropriate because the disease models, administration routes, doses, particle properties, and therapeutic endpoints differ substantially.

Immunomodulation for Adjuvant Disease Therapy

Immunomodulatory agents can support disease treatment by regulating immune-cell activity and balancing immune responses.⁹³ TCM-derived agents may act through multiple pathways, but their biocompatibility and adverse-effect profiles remain product- and dose-dependent. Co-assembled nanosystems may modify the distribution and release of these compounds, but their contribution must be separated from intrinsic drug effects. A triterpenoid assembly-driven system co-delivering betulinic acid and a cyclin-dependent kinase 4/6 (CDK4/6) inhibitor showed chemoimmunotherapeutic activity in the reported model. It remodeled the immunosuppressive tumor microenvironment and increased immune activation.⁹⁴ In another study, a self-assembled chitosan–puerarin hydrogel modulated macrophage polarization.⁹⁵ The formulation reduced pro-inflammatory gene expression, increased anti-inflammatory gene expression, and supported antibacterial activity and wound repair.⁹⁵ A nanovaccine assembled from chitosan oligosaccharide, Ganoderma lucidum polysaccharide, and tumor-cell lysate facilitated antigen delivery to dendritic cells, promoted dendritic-cell maturation, and produced antitumor effects in the tested model.⁹⁶

These three systems differ in material design. The betulinic acid system is an active-component cancer nanomedicine; the chitosan–puerarin system is a polymer-based wound hydrogel, and the Ganoderma lucidum system is a biomacromolecule-based nanovaccine. Their immune endpoints and disease models are not directly comparable, and the reported effects may arise from active compounds, auxiliary materials, assembled architecture, or their combination. Matched non-assembled controls and longer safety studies are needed before a general immunomodulatory advantage can be attributed to TCM-derived self-assembly.

Other Diseases

TCM-derived self-assembly has also been investigated in metabolic disorders and infectious diseases. Curcumin–glycyrrhetinic acid nanoparticles combine direct drug–drug co-assembly with mild photothermal treatment to regulate lipid metabolism and inflammation in an obesity model.⁹⁷ By contrast, EGCG–Au nanoparticles rely on metal–phenolic coordination and irradiation-induced reactive oxygen species (ROS) generation to damage drug-resistant bacteria and biofilms.⁹⁸ Because the disease models, material compositions, and external energy inputs differ, these systems should be interpreted as independent preclinical proof-of-concept formulations rather than evidence of a general therapeutic advantage of TCM self-assembly.

Targeted and Intelligent Responsive Delivery Systems

TCM-derived self-assembled systems have been investigated as a means of modulating the distribution and release of active components from Chinese herbal medicines. The reported delivery strategies can be broadly divided into two categories. The first is surface-mediated active targeting, in which ligands or biological membranes are introduced to enhance the recognition of diseased cells or tissues. However, this targeting function does not necessarily originate from the self-assembled core. For example, a biomimetic nano-TCM platform for immunotherapy against rheumatoid arthritis was constructed through the carrier-free co-assembly of celastrol and Calculus Bovis-derived bilirubin. The resulting nanoparticles were subsequently camouflaged with hyaluronic acid (HA)-functionalized erythrocyte membranes. The HA coating was designed to exploit its affinity for cluster of differentiation 44 (CD44) receptors expressed on pro-inflammatory M1 macrophages. The resulting formulation was reported to show enhanced targeting toward these macrophages (Figure 11A).⁹⁹ In another study, nanoparticles were co-assembled via non-covalent interactions using the Astragalus derivative LS102 and the Angelica active ingredient Z-ligustilide as core components. The study reported increased accumulation of the formulation in injured myocardium after platelet-membrane and cyclic arginine-glycine-aspartic acid (cRGD) modification.¹⁰⁰ Thus, both systems contain a TCM-derived co-assembled core but rely mainly on externally introduced membranes or ligands for targeting. Their targeting effects should therefore not be attributed to self-assembly alone.

Figure 11.

(A) HA-RM-Cel-BR evades immune elimination and possesses prolonged systemic circulation owing to red blood cell membrane camouflage. Via HA-mediated active targeting, this nanoplatform preferentially accumulates in inflamed joints and alleviates local inflammation. The upward arrows (↑) indicate increased IL-10 expression and Treg cells, whereas the downward arrows (↓) indicate decreased Th17 cells and plasma cells. Copyright 2025, Springer Nature.⁹⁹ (B) Schematic diagram of LUT@POP-FH-Mn showing pH-responsive release under weakly acidic conditions. Copyright 2026, Elsevier.¹⁰¹

The second approach involves lesion-associated accumulation and stimulus-responsive drug release. Some TCM-derived self-assembled formulations are designed to promote lesion accumulation and stimulus-dependent release; however, the extent and specificity of these effects require validation under in vivo conditions. The enhanced permeability and retention (EPR) effect may contribute to the passive accumulation of nanostructures in some tumor models. Nevertheless, its magnitude can vary, and uniform tumor accumulation should not be assumed. Elevated glutathione, ROS, and acidic pH in the tumor microenvironment have been widely exploited as design cues for responsive TCM-derived delivery systems.¹⁰² For example, a trimeric prodrug containing defined disulfide and cinnamaldehyde–thiophosphate linkages was constructed from ligustrazine, paclitaxel, and the poly(ADP-ribose) polymerase (PARP) inhibitor olaparib. The disulfide linkage was designed to undergo cleavage under high glutathione (GSH) levels, whereas the ROS-responsive linkage enabled further component release under tumor-mimicking conditions.¹⁰³ This responsiveness is encoded mainly in chemically cleavable covalent linkages and is therefore distinct from non-covalent monomer self-assembly. Moreover, responsiveness observed in buffer or tumor-mimicking media may not fully predict release behavior in vivo, where dilution, protein binding, enzymatic degradation, and competing ions can alter the assembly state. By comparison, Polygonatum odoratum polysaccharide, luteolin, and Mn²⁺ formed a pH-responsive non-covalent hybrid co-assembly. Its reported release behavior was consistent with structural destabilization under acidic conditions (Figure 11B).¹⁰¹ The two systems therefore rely on different responsive mechanisms. The trimeric prodrug depends on the cleavage of covalent linkages, whereas the polysaccharide–luteolin–Mn²⁺ system involves the destabilization of a multicomponent assembly. Because the latter contains a polysaccharide and an inorganic ion, it is better classified as a TCM-derived hybrid assembly.

The two targeting and release pathways of TCM self-assembly systems are not mutually exclusive. In practice, they are often combined to construct dual-functional “active targeting–intelligent response” drug delivery systems.¹⁰⁴ However, increasing the number of functional elements also makes mechanistic attribution more difficult. The respective contributions of the self-assembled core, membrane or ligand modification, and responsive linkage should therefore be evaluated using appropriate controls.

Tissue Repair and Regenerative Medicine

The fundamental aim of regenerative medicine is to restore the physiological function of injured tissues and organs. Benefiting from favorable biocompatibility, degradability and intrinsic bioactivities, self-assembling materials derived from TCM have exhibited considerable potential across diverse regenerative scenarios, covering vascular,¹⁰⁵ cartilage,¹⁰⁶ bone,¹⁰⁷ nerves,¹⁰⁸ teeth,¹⁰⁹ and soft tissues.¹¹⁰ In the GA hydrogel integrated with extracellular vesicles and the puerarin–silk fibroin nanofibrillar hydrogel, TCM-derived molecules are directly involved in the formation of the local matrix or scaffold.^108,111 In contrast, curcumin–polyaminopropyl biguanide nanoparticles and naringin–curcumin nanoparticles are further incorporated into hydrogel matrices. In these cases, the hydrogel mainly acts as a local reservoir, while the assembled nanoparticles serve as the primary pharmacologically active components.^109,110 The sodium alginate/GA hydrogel loaded with Netrin-1 (SA/GA@Netrin-1) patch can be regarded as an intermediate design, since a TCM-derived component participates in the hybrid matrix, whereas Netrin-1 provides an additional regenerative signal (Figure 12).¹¹²

Figure 12.

Schematic diagram for the fabrication of SA/GA@Netrin-1 patch and its function mechanism in diabetic wound treatment. Copyright 2025, American Chemical Society.¹¹²

Overall, these systems indicate that TCM-derived assemblies may enable local retention, sustained release, structural support, and regulation of inflammation or tissue repair. However, these effects are highly system-dependent. Variations in matrix composition, mechanical properties, injury models, and evaluation endpoints also make it difficult to establish a unified structure–regeneration relationship at present.

Integrated Diagnosis and Therapy

TCM-derived assemblies have been studied as formulations that combine two or more therapeutic or imaging functions. Ordered co-assembly has been used to combine TCM bioactive ingredients with photosensitizers, sonosensitizers, or magnetic components. For instance, co-assembly of Rh, an anticancer active component, with a photosensitizer has achieved synergistic effects of chemotherapy and photothermal therapy. Upon laser irradiation, such assemblies enhance the cellular uptake of Rh and strengthen its antitumor efficacy.¹¹³ An artesunate–TTQ conjugate, in which TTQ is an aggregation-induced emission organic sonosensitizer, was formulated into nanosonosensitizers through DSPE–PEG2000-assisted self-assembly. Dually activated by ultrasound and intracellular ferrous ions, this nanosystem exhibited robust ROS generation and potent tumor suppression in mouse tumor models.¹¹⁴ Moreover, the integration of magnetically responsive moieties allows magnetically targeted delivery of active ingredients, thereby improving drug delivery efficiency.¹¹⁵ Notably, nanosystems formed by co-assembly of TCM monomers with other therapeutic agents can enable the sequential release of multiple components and exert their therapeutic effects in a coordinated manner, thus enabling multicomponent synergistic therapy. As an example, an intelligent nanoplatform formed through the co-assembly of triptolide and metformin responds to the lesion microenvironment and achieves spatiotemporally cascaded synergistic therapy ranging from vascular regulation to immunomodulation and bone protection.¹¹⁶ These systems combine therapy with photothermal, sonodynamic, magnetic, or microenvironment-responsive functions. However, the added sensitizer, magnetic component, covalent linkage, or auxiliary polymer often provides the key external function. The evidence therefore supports multifunctional integration. It does not show that TCM-monomer self-assembly alone produces theranostic performance.

TCM-derived assemblies have also been studied as platforms for combining imaging and therapy. In one example, indocyanine green (ICG) promoted the assembly of a paclitaxel prodrug into nanoparticles used for imaging and chemotherapy (Figure 13).¹¹⁷ This study supports functional integration within one formulation. However, it does not establish diagnostic–therapeutic synergy. Most reports remain limited to imaging feasibility and small-animal efficacy. Few studies show that imaging information changes treatment decisions or improves therapeutic outcomes.

Figure 13.

(A) Schematic illustration of the preparation of indocyanine green-potentiated paclitaxel nanoprodrugs (IPS NPs) from the co-assembly of indocyanine green (ICG) and paclitaxel (PTX) prodrug, and (B) ICG-potentiated prodrug delivery for tumor-specific chemotherapy and real-time therapeutic feedback. Copyright 2022, Wiley.¹¹⁷

Conclusion and Perspective

Established Advances and Evidence Boundaries

Current evidence indicates two relatively well-supported advances in TCM-derived self-assembly research. The first is that selected, structurally defined TCM-derived molecules can function both as bioactive agents and as supramolecular building blocks. When the active molecules themselves form the structural framework, the formulation moves beyond conventional drug loading toward a “drug-as-structure” model.⁶⁵

The second advance is a shift from single-factor descriptions toward a multivariable understanding of assembly. In individual systems, hydrophobicity, aromatic stacking potential, hydrogen-bonding capacity, ionization state, component ratio, pH, solvent composition, temperature, and ionic strength have each been associated with assembly outcomes. However, their relative contributions remain compound- and context-dependent, and no universal hierarchy has yet been established. Changes in dispersibility, colloidal persistence, local retention, or release should therefore be interpreted as system-specific structure–property relationships. Claims of biological synergy should be reserved for studies supported by appropriate quantitative combination analyses.⁶⁵

The conceptual advance, therefore, extends beyond nanoscale size reduction: selected natural molecules may retain pharmacological activity while also possessing an intrinsic propensity to assemble. This principle is most clearly represented by carrier-free systems. Hybrid formulations occupy a different position because polymers, biomacromolecules, metal ions, or biological membranes may contribute substantially to stability, mechanical behavior, targeting, or biological identity.⁹⁹ Mechanistic interpretation must therefore distinguish the intrinsic pharmacology of the components, the properties arising from the assembled state, and the functions introduced by auxiliary materials. Likewise, an assembly pathway should not ordinarily be assigned from a single spectroscopic or imaging result; convergent evidence from orthogonal analytical methods is required.

The evidence boundary is equally clear. The application studies surveyed here are overwhelmingly preclinical and rely mainly on cell culture and small-animal models.²⁴ Without dose-matched unassembled mixtures, deliberately disrupted assemblies, and conventional-formulation comparators, improved biological outcomes cannot be attributed solely to self-assembly. Clinical efficacy and transferable structure–function relationships therefore remain to be established.

Remaining Challenges and Research Priorities

Reproducibility begins with control of the source materials. For herbal starting materials, botanical authentication, controlled extraction and processing, marker quantification, contaminant testing, and chemical fingerprinting are established elements of quality assurance.¹¹⁸ For isolated TCM-derived monomers, chemical identity should be complemented by quantitative purity and impurity profiles, counterion and water content, and solid-form characterization. Pharmaceutical solid-form research shows that solid-state differences can alter stability, dissolution, and manufacturability.¹¹⁹ However, whether they also change the self-assembly of a given TCM monomer remains largely untested. Possible effects on nucleation, critical assembly concentration, particle-size distribution, or morphology should therefore be treated as risks to be examined rather than established consequences. Reproducibility should be demonstrated across independent raw-material lots and independently prepared assembly batches using predefined chemical and structural attributes.^118,119

The studies surveyed here also do not consistently report long-term colloidal stability, and stability during storage is not equivalent to behavior in biological media. Recent studies outside the TCM field show that protein coronas can modify nanoparticle performance. In lipid nanoparticles, corona composition altered cellular uptake and intracellular trafficking, and greater uptake did not necessarily produce greater mRNA expression.¹²⁰ In polymer-modified lipid nanovesicles, surface functional-group density changed corona composition, circulation, and tissue-dependent cellular internalization.¹²¹ These findings do not establish the same effects in TCM-derived carrier-free assemblies; rather, they identify mechanisms that warrant system-specific testing. A TCM-focused review similarly identifies absorption, transport, and distribution as unresolved dimensions of the in vivo fate of self-assembled TCM ingredients.⁵⁵ Relevant studies should therefore examine serum stability, dilution-induced destabilization, protein adsorption, enzymatic degradation, and in vivo disassembly, while distinguishing intact assemblies from released or metabolized components whenever technically feasible.^120,121 For systemic or repeated administration, complement activation, cytokine responses, and repeated-dose immunogenicity also merit product-specific evaluation. This recommendation is extrapolated from the broader nanomedicine literature and has not yet been demonstrated generally for TCM self-assembled systems.¹²²

A carrier-free composition does not remove manufacturing complexity. A recent perspective on carrier-free nanodrugs identifies unpredictable assembly and unclear in vivo fate as persistent translational barriers,¹²³ while an industry perspective on nanomedicine emphasizes product-specific chemistry, manufacturing, and control challenges involving physicochemical characterization, quality attributes, and stability.¹²⁴ A quality-by-design framework provides a practical means of connecting critical material attributes and process parameters with measurable product quality.¹²⁵ Depending on the preparation route, mixing order, concentration, pH, temperature, shear, and solvent-removal rate should be screened as candidate process variables rather than presumed to exert fixed effects. Relevant quality attributes may include chemical composition, free and assembled fractions, particle-size distribution, morphology, release behavior, and colloidal stability, although the final set must be justified for each product.^123–125

Regulatory uncertainty warrants similar restraint. Comparative analyses of the European and US regulatory landscapes indicate that nano-enabled health products may enter different pathways according to their composition, intended use, and mode of action, while nano-specific requirements remain fragmented.¹²⁶ The literature surveyed here does not identify a dedicated regulatory category for multicomponent carrier-free TCM supramolecular assemblies. The contribution of each active component, structural consistency, in vivo fate, and nanomaterial-related risks are consequently likely to require case-specific justification.^123,124

Progress toward predictive design will depend less on accumulating additional isolated examples than on generating comparable evidence. Molecular descriptors, component ratios, and environmental conditions should be varied systematically, and both successful and failed assembly outcomes should be reported. Computational or data-driven models may then become useful, but only when the underlying experiments use standardized preparation, characterization, and metadata. The scarcity of failed or non-reproducible outcomes in the literature surveyed here currently makes it difficult to distinguish robust design principles from conditions identified through system-specific optimization.

Causal structure–function analysis is equally important. In situ and time-resolved measurements should be paired with dose-matched unassembled mixtures, deliberately disassembled formulations, and conventional comparators. Pharmacokinetic and biodistribution methods should, where technically possible, differentiate intact assemblies from dissociated or metabolized components.⁵⁵ A credible translational sequence would therefore combine independent-batch validation, scale-up sensitivity analysis, biological-fluid stability, product-specific immune assessment, and in vivo fate studies before claims of clinical utility are advanced.^122–125 Early dialogue with the relevant regulatory authority may clarify product-specific data expectations, but it should not be presented as evidence that a universal regulatory pathway already exists.¹²⁶

In summary, TCM-derived self-assembly is better regarded as an emerging molecular-engineering strategy than as a clinically established platform. Its principal conceptual contribution is the demonstration that selected natural molecules can couple pharmacological activity with structural organization. The next substantive advance will not arise from increasing the number of reported self-assembled systems alone, but from converting system-specific observations into reproducible and causally supported design rules and testing them under physiologically and clinically relevant conditions.

Funding Statement

This work was financially supported by grants from the Jilin Province Science and Technology Development Plan Projects (Grant No. YDZJ202601ZYTS523).

Abbreviations

AFM, atomic force microscopy; API, active pharmaceutical ingredient; cryo-EM, cryogenic electron microscopy; BBR, berberine; BP, borax–puerarin; DLS, dynamic light scattering; DSC, differential scanning calorimetry; EGCG, epigallocatechin gallate; EPR, enhanced permeability and retention; FT-IR, Fourier-transform infrared spectroscopy; GA, glycyrrhizic acid; GSH, glutathione; HPLC, high-performance liquid chromatography; HR-MS, high-resolution mass spectrometry; isoG, isoguanosine; ITC, isothermal titration calorimetry; LC–MS, liquid chromatography–mass spectrometry; MAPK, mitogen-activated protein kinase; MD, molecular dynamics; MMF, mycophenolate mofetil; NF-κB, nuclear factor kappa B; NMR, nuclear magnetic resonance; NTA, nanoparticle tracking analysis; PBA, phenylenebisboronic acid; PDI, polydispersity index; PVA, polyvinyl alcohol; Rh, rhein; ROS, reactive oxygen species; RPS, resistive pulse sensing; SAXS, small-angle X-ray scattering; SEM, scanning electron microscopy; STM, scanning tunneling microscopy; TCM, traditional Chinese medicine; TEM, transmission electron microscopy; TGA, thermogravimetric analysis; UHPLC–HR-MS, ultra-high-performance liquid chromatography–high-resolution mass spectrometry; UV–Vis, ultraviolet–visible spectroscopy; XRD, X-ray diffraction; ZR1, zingibroside R1.

Disclosure

The authors report no conflicts of interest in this work.