Table 4.

Hybrid hydrogels as functional wound dressings.

Base Component	Secondary Component	Functionality	Outcome(s)	Refs.
Chitosan	Dextran-dopamine	pH-responsive controlled drug release Antibacterial activity Angiogenic activity Adhesive property	Controlled release of silver nanoparticles (AgNPs) and deferoxamine in acidic environments AgNPs release showed rapid antibacterial activity and simultaneous deferoxamine release promoted angiogenesis by enhancing the expression of hypoxia-inducible factor-1 alpha (HIF-1α) and VEGF	[49]
Chitosan	Poly(vinyl alcohol) (PVA)	Antimicrobial effect Sustained release of Ag+ and epidermal growth factor (EGF)	Enhanced re-epithelization Sufficient collagen deposition	[50]
Chitosan	Poly(d,l-lactide)-poly(ethylene glycol)-poly(d,l-lactide) (PLEL)	Thermo-sensitive Antibacterial activity Adhesive properties	Catechol modified quaternized chitosan (QCS-C) enhanced tissue adhesion Enhanced antibacterial properties Loading nano-scaled bioactive glass promoted angiogenesis by up-regulating the gene expression of VEGF and b-FGF Enhanced wound healing	[51]
Chitosan	Hyaluronic acid (HA)	Adhesive properties Anti-inflammatory activity Antioxidant effect	Catechol-containing hydrogels presented adhesion strength to the wet surfaces Supported mesenchymal stem cell growth, migration, and proliferation Protected cells against oxidative stress by controlled and sustained in situ delivery of catechol Promoted down-regulation of the pro-inflammatory cytokine IL-1β	[52]
Chitosan	Alginate and Polydeoxyribonucleotide (PDRN)-loaded CaCO3 nanoparticle (PCNP)	Controlled gene delivery Anti-inflammatory Pro-angiogenic	PCNP improved the in situ delivery efficacy of PDRN Accelerated proliferation of fibroblasts Increased amount of collagen fiber deposition, blood vessel formation, and cell attachments Accelerated wound healing	[53]
Chitosan	Gelatin	Biodegradable Biocompatible	Uniformly interconnected 3D porous structures Tailored degree of swelling and degradation behavior by increasing photocrosslinking and increasing gelatin concentration	[54]
Chitosan	Oxidized HA-graft-aniline tetramer (OHA-AT)	Biodegradable Antibacterial activity Electroactive Antioxidant effect Neovascularization	Accelerated wound healing by increasing granulation tissue thickness, collagen disposition and angiogenesis Amoxicillin loading added effective antibacterial activity	[55]
Chitosan	Arginine-based poly(ester urea urethane) (Arg-PEUU)	Anti-inflammatory activity Antibacterial activity Biodegradable	Methacrylate-modified chitosan (CS-GMA) and Arg-PEUU hybrid hydrogels exhibited an excellent antibacterial activity Hybrid hydrogel showed high water content, a three-dimensional microporous network structure, cytocompatibility, and enzymatic biodegradability	[56]
Chitosan	Decellularized extracellular matrix (dECM) and Gelatin	Antibacterial Biocompatible	Interconnected pore structure with high porosity promoted cell growth Degradation rate matched with the new tissue formation in skin tissue engineering Antibacterial activity Maintained the moisture and nutrition balance	[57]
Chitosan	Gallic acid (GA)	Adhesive property Antibacterial activity Homeostasis properties	Exhibited favorable antioxidant properties, high biocompatibility, and haemocompatibility High capacity of homeostasis and promoted wound healing	[58]
Chitosan	PVA and PEG	pH/glucose-triggered drug release Anti-inflammatory Neovascularization	pH and glucose-responsive drug delivery activity Enhanced wound closure rate, inflammatory infiltrate, neovascularization, and collagen deposition with the incorporation of the insulin/L929 into the hydrogel in vivo diabetic wounds	[59]
Gelatin	Lipopeptide-surfactin (SF)	Angiogenic activity Anti-inflammatory	GelMA-SF hydrogels promoted diabetic wound healing via regulating macrophage polarization and promoting angiogenesis	[60]
Agar	Fumaric acid (FA) and incorporated Ag NPs	Antibacterial Biodegradable	Controlled Ag ion release and microbial growth inhibition Accelerated healing rate with promising epithelialization, angiogenesis, and less lipid peroxidation Organized collagen deposition	[61]
Dextran	Poly(ethylene glycol) diacrylate (PEGDA)	Biodegradable Neovascularization Pro-angiogenic	Slower degradation of the dextran hydrogel with the high content of nondegradable PEGDA and higher cross-linking density Dextran hydrogel promoted rapid, efficient, and functional neovascularization without the addition of growth factors or cytokines Neutrophil cell infiltration expedited hydrogel degradation, which lead to vascular cell infiltration. Complete skin regeneration	[62]
Dextran	PEG	Controlled release of immune stimulatory cargo proteins Anti-inflammatory	Controlled release of cargo proteins Improved retention and effectiveness of an immune-stimulatory protein in the wound environment	[63]
Methylcellulose	Pluronic F-127	Thermosensitive controlled release of MMP-9 siRNA Gene delivery	Down-regulation of MMP-9 expression Enhanced diabetic wound healing	[64]