Gold Nanoparticles and Chitosan Nanoparticles: A Systematic Review

Abstract

Gold nanoparticles (AuNPs) and chitosan nanoparticles (CNPs) have emerged as multifunctional nanomaterials in biomedical sciences, particularly in conservative and endodontic dentistry. Thei antimicrobial, biocompatible, and regenerative properties make them promising candidates for enhancing clinical outcomes. This systematic review aimed to evaluate and synthesize the current evidence on the application of AuNPs and CNPs in endodontics and conservative dentistry. A systematic literature search was performed using PubMed, Scopus, and Web of Science databases up to April 2025. Studies focusing on the synthesis, characterization, and dental application of AuNPs and/or CNPs were included. After applying Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, 10 studies were selected and analyzed qualitatively. Most studies demonstrated strong antimicrobial efficacy of chitosan–AuNP composites against biofilm-forming bacteria relevant to caries and endodontic infections. Some studies also highlighted enhanced sealing ability, siRNA delivery, drug release, and photothermal therapeutic applications. Several formulations showed high biocompatibility and regenerative potential. Gold and CNPs present significant promise in improving antimicrobial disinfection, restorative sealing, and regenerative outcomes in dentistry. However, further in vivo and clinical research is necessary to confirm their long-term safety and efficacy.

INTRODUCTION

Nanotechnology has significantly influenced dental materials and therapeutics, especially in endodontics and conservative dentistry. Among various nanomaterials, gold nanoparticles (AuNPs) and chitosan nanoparticles (CNPs) have emerged as promising agents due to their unique physicochemical properties and biocompatibility. AuNPs exhibit excellent antimicrobial action, surface functionalization, and optical behavior, making them ideal for disinfection and visualization during dental procedures.[1,2] Similarly, chitosan, a natural biopolymer derived from chitin, offers inherent antibacterial, hemostatic, and bioadhesive properties, enhancing its utility in caries prevention, intracanal medicaments, and regenerative endodontics.

MATERIALS AND METHODS

This systematic review was conducted in accordance with PRISMA guidelines. A comprehensive literature search was performed across PubMed, Scopus, and Web of Science databases up to April 2025 using the following keywords: “gold nanoparticles,” “CNPs,” “endodontics,” “conservative dentistry,” “dental nanotechnology,” and their combinations. Boolean operators (AND/OR) were applied to refine the search. Inclusion criteria consisted of: (1) original in vitro, in vivo, or ex vivo studies; (2) studies evaluating AuNPs or CNPs in endodontic or restorative dental applications; (3) English-language articles; and (4) publication in peer-reviewed journals. Exclusion criteria included: (1) review articles, editorials, or conference abstracts; (2) studies unrelated to dental applications; and (3) articles with insufficient methodological detail.

RESULTS

The selected studies encompass diverse in vitro and ex vivo research, mainly targeting antimicrobial, sealing, or regenerative roles of gold and CNPs. Most investigations utilized biologically or chemically synthesized nanoparticles, with potential applications in conservative dentistry, especially for disinfection, material enhancement, and bioactivity modulation [Table 1].

Table 1.

Characteristics of included studies

Study No.		Year		Author (First)		Type of study		Application		Nanoparticle type
1		2022		Chittratan P		In vitro		Cariogenic bacteria control		Chitosan–gold–thymol NPs
2		2024		Rane S		In vitro		Apical leakage in root canals		Chitosan NPs in sealers
3		2021		Shaabani E		In vitro		Gene delivery potential		Chitosan-coated AuNPs
4		2020		Fuster MG		In vitro		Antibacterial action		Chitosan–gold NPs
5		2022		Mostafa EM		In vitro		Anti-biofilm activity		Fungus-synthesized AuNPs
6		2021		Hussein MAM		In vitro		Endodontic disinfection		AuNPs + Punica extract
7		2024		Zhao M		Ex vivo		Chemoembolization therapy		AuNP–chitosan nanocomposite
8		2022		Zhang Y		In vitro		Phototherapy and disinfection		Curcumin-loaded Au-CNPs
9		2022		Panichikkal J		In vitro		Bioactivity modulation		AuNPs with rhizospheric bacteria
10		2025		Kowalska A		Review		Dental applications summary		Chitosan and gold NP overview

NPs: Nano particles, AuNPs: Gold nanoparticles, CNPs: Chitosan nanoparticles

Antimicrobial efficacy was consistently high across most studies, particularly against biofilms and cariogenic pathogens. Several formulations demonstrated good biocompatibility, supporting their dental use. Some studies also reported regenerative or gene delivery potential, indicating a dual role of these nanoparticles in both disease control and tissue engineering [Table 2].

Table 2.

Summary of applications in endodontics and conservative dentistry

Study No.		Target use case		Antimicrobial effect		Biocompatibility		Regenerative potential
1		Caries inhibition		High		Moderate		Not reported
2		Root canal sealing		Moderate		High		Not applicable
3		siRNA delivery		Low		High		Potential use
4		Biofilm control		High		High		Not explored
5		Disinfection		High		Not specified		No
6		Pulpal infection		High		High		Not explored
7		Drug release system		Not tested		High		Moderate
8		PDT and PTT		High		High		Potential
9		Growth modulation		Moderate		High		Yes
10		Review insights		-		-		-

PTT: Photothermal, PDT: Photodynamic therapy

DISCUSSION

The use of layer-by-layer (LbL) assembled chitosan-coated AuNPs for siRNA delivery by Shaabani et al.[3] opens new directions for regenerative endodontics, particularly in gene-modulated repair or stem-cell activation. Fuster et al.[4] and Mostafa et al.[5] reported the superior antimicrobial performance of biosynthesized chitosan–gold composites against oral pathogens, with minimal cytotoxicity, suggesting a favorable safety profile. Hussein et al.[6] further enhanced this potential by integrating Punica granatum extracts, yielding synergistic antimicrobial properties suitable for root canal irrigants or intracanal medicaments.

Beyond disinfection, Zhao et al.[7] explored AuNP–CNP nanocomposites for controlled chemoembolization—potentially useful for localized delivery of anti-inflammatory or regenerative agents in periapical lesions. Similarly, Zhang et al.[8] introduced a photodynamic and photothermal platform utilizing curcumin-functionalized Au-CNPs, which combines antimicrobial and healing actions. These multimodal approaches not only offer disinfection but also reduce reliance on systemic antibiotics, which is critical amid rising antimicrobial resistance.

Panichikkal et al.[9] examined the biological influence of AuNPs in promoting growth factor release and enhancing cell proliferation, affirming their regenerative capabilities. Kowalska et al.’s[10] review further consolidates these findings, reinforcing the translational relevance of chitosan–gold nanomaterials in modern dental therapies.

CONCLUSION

Gold and CNPs exhibit significant promise in conservative and endodontic dentistry due to their antimicrobial, bioactive, and regenerative potential. Their synergy offers enhanced therapeutic outcomes, from disinfection to tissue repair.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.