Table 1.

Compositions and physicochemical properties of prepared hydrogels for determining biomedical application diversity

	Hydrogel material	Cross-linking method	Bioactivity	Degradability	Network pore size	Viscoelasticity	Stiffness	References
Natural material	Collagen	•pH and temperature •TG, Ca2+ •PEG-diNHS •Methacrylation/photopolymerization	Col-derived triple-helical ligands (e.g., GxOGER)—β1-containing integrins, RGD peptides	Collagenase, MMPs, plasmin, pepsin	Fibrous	Viscoelastic	•10–250 Pa (G’)	74,75
	Gelatin	•TG, Ca2+ •Methacrylation/photopolymerization •ferulic acid (FA) conjugation/Laccase (O2)	RGD—α5β1 and αvβ3	Collagenase, MMPs, plasmin, pepsin	Macroporous	Viscoelastic	•11–1800 Pa (G’)	79
	Hyaluronic acid (HA)	•Acrylation/photopolymerization •Host–guest interaction	Specially reacts with CD44 receptor	Hyaluronidase, MMPs	–	Viscoelastic	•1.3–10.6 kPa (E)	81–83
	Alginate	•Divalent cations (e.g., Ca2+ or Ba2+) •Oxidation + gelatin	/	Chelator (e.g., sodium citrate, EDTA, etc.)	Nanoporous	Viscoelastic	•0.5–3 kPa (G’)	5,84
	Fibrin	•Thrombin/Ca2+ •PEG-diNHS	RGD—α5β1 and αvβ3	chymotrypsin, actinase, carboxylase, etc.	Fibrous	Viscoelastic	•0–8 kPa (G’)	85
	Chitosan	•Glutaraldehyde •Genipin •Diisocyanate	/	Hydrolysis	Macroporous	Viscoelastic	•2–30 kPa (G’)	86
	Agarose	•Temperature	/	Hydrolysis	–	Viscoelastic	•1–120 kPa (G*)	87
	Polypeptide	•Self-assembly	-	Enzyme	Fibrous	Viscoelastic	•500–2500 Pa	89–91
	DNA	•Base pairing	/	Nuclease	–	Viscoelastic	•4–23 kPa (E’)	92,93
Synthetic material	PEG	•Acrylation/photopolymerization •Thiolation	/	Hydrolysis	–	Elastic	•1–1200 kPa (compression stress)	95
	PVA	•Calcium gluconate •Glutaraldehyde, etc.	/	Hydrolysis	–	Elastic	•3.7–30.2 kPa	96–98
	PCL	•Temperature	/	Hydrolysis	–	Elastic	•~5 MPa (compressive strength)	101
	Polyacrylamide	•Free radical copolymerization	/	Hydrolysis	–	Elastic	•0.1–740 kPa	99,100
	Polyurethane (PU)	•Temperature	/	Hydrolysis	–	Elastic	•0.68–2.4 kPa (E’)	102,103

Note: / indicates none; - represents depending