Table 1.

Summary of natural-polymer-based hydrogels for antimicrobial therapy.

Matrix Material	Superiority	Hydrogel	Modification	Highlight	Antimicrobial Activity	Mechanism	Reference
Chitosan (CS)	electropositive, effective killing of microorganisms by electrostatic interaction	BP/CS-bFGF hydrogel	carboxymethyl chitosan	Basic fibroblast growth factor was added to promote tissue regeneration.	S. aureus, E. coli > 67%	electrostatic interaction between carboxymethyl chitosan and bacteria	[50]
		CSG-PEG/DMA/Zn hydrogel	amidation reaction of polyethylene glycol monomethyl ether	be prepared by photoinitiated polymerization; multifunctional platform for antibacterial and anti-oxygen adhesion and hemostasis	S. aureus, E. coli, MRSA ≈100%	sustained release of the antimicrobial agent Zn2+	[51]
Polydopamine (PDA)	high viscosity; intrinsic photothermal properties	CAC/PDA/Cu(H2O2) hydrogel	CuSO4 and H2O2 accelerate the deposition rate of PDA	bionic mussels	S. aureus =99.87%; E. coli = 99.14%; MRSA = 99.25%	electrostatic interaction between carboxymethyl chitosan and bacteria; Sustained release of antimicrobial Cu2+	[52]
		CG/PDA@Ag hydrogel	in situ grown Ag; evenly disperse in guar glue hydrogel	Combined with photothermal therapy, the photothermal conversion efficiency of PDA is improved.	S. aureus =99.8%; E. coli = 99.9%	electrostatic interaction between guar gum and bacteria; sustained release of antimicrobial agent Ag+; photothermal effect of Ag@PDA	[53]
Gelatin	beneficial for fibroblast adhesion and growth	Gelatin-based hydrogel loaded with AgPOM	-	responsive to the acidic infectious environment	MRSA > 90%	photothermal effect of AgPOM; 1O2 formed by the reaction with H2O2	[54]
		GelMA-EGF/Gelatin-MPDA-LZM hydrogel	be amidated by methylacrylamide	photothermal and lysozyme synergistically remove biofilm and antibacterial activity	E. coli = 98.08%	photothermal effect of MPDA; lysozyme	[55]
Agarose	Stable thermally reversible hydrogels can be formed by physical cross-linking without the addition of cross-linking agents.	Gel1(Cyan)/Gel2(PCN) hydrogel	-	real-time monitoring; self-oxygenation enhances the photodynamic effect	S. aureus, E. coli, MRSA > 80%	photodynamic effects of oxygen-enhanced PCN-224	[56]
		CMA-Ag hydrogel	be amidated by carboxymethyl group	response to temperature and pH; The onset time of the inflammatory phase was earlier and the duration was shorter.	S. aureus, E. coli ≈ 100%	Sustained release of the antimicrobial agent Ag+	[57]
Hyaluronic acid (HA)	promoting granulation tissue regeneration and re-epithelialization; reducing inflammatory cell infiltration	HA-PEGSB-CMP hydrogel	be amidated by adipyl dihydrazide	good mechanical properties, can be used for motion wounds	EC, MRSA ≈ 100%	photothermal properties of the cuttlefish melanin nanoparticles	[58]
		BSP-U/DAHA hydrogel	be amidated by aldehyde group	Sol-gel transition can be achieved in response to photothermal and pH.	S. aureus =91.68%; E. coli = 94.94%	photothermal properties of hydrogels formed by cross-linking of catechol and Fe3+ ligands	[59]
Cellulose	Modifications can be made without compromising the structural and mechanical properties.	RPC/PB hydrogel	-	pH response intelligently releases the drug	S. aureus =84.3%	antimicrobial properties of resveratrol	[60]
		BC/GG-Cu@ZIF/GOx hydrogel	-	response to glucose	S. aureus, E. coli ≈ 100%	nanozymes consume glucose and generate ·OH antimicrobial agents	[61]
Alginate	nonimmunogenic and nonthrombotic	TO/ASP hydrogel	be amidated by diacetone acrylamide	not affected by environmental pH and has good antibacterial activity in the range of pH 4–9	S. aureus =99.92%; E. coli = 99.993%	antimicrobial properties of antimicrobial peptides, thymol, and oligomeric tannic acids	[62]
		ALG-HPR hydrogel	-	NIR responsiveness; long-term release of the drug	S. aureus ≈ 100%	photothermal properties of indocyanine green; antimicrobial properties of rifampicin.	[63]