Table 4.

(continued). Representative biomedical application scenarios, micro/nano-scale design requirements, and validation considerations for HM-based platforms synthesized from the present analysis and relevant literature

Application Scenario	Biological/Clinical Challenge	Required Micro/Nano-Scale Properties	Representative Nano-Enabled Design Strategies	Characterization and Translational Bottlenecks
Organ-on-a-chip/disease modeling	Reconstructing tissue microenvironments	ECM-mimetic, tunable stiffness, modularity	Cell-laden microgels, multicompartmental HMs	Standardization, reproducibility, model validation
Controlled-release and long-acting delivery	Burst release, short exposure, unstable release profile	High loading, controlled diffusion, predictable degradation, formulation stability	PLGA/alginate/chitosan HMs, thermosensitive HMs, core–shell HMs	Release reproducibility, IVIVC, scale-up, storage stability
Bioimaging and biosensing	Signal stability, tissue penetration, biological background interference	Stable labeling, responsive interfaces, reproducible particle size, nanocomposite integration	Fluorescent/magnetic HMs, nanoparticle-integrated HMs, stimuli-responsive microgels	Sensitivity, specificity, calibration, long-term signal stability, in vivo tracking