Table 3.

The advantages and disadvantages of synthetic hydrogels

	Advantages	Disadvantages	References
Polyethylene glycol (PEG)	Highly versatile for modifications, can serve as carrier for drugs, ECM, growth factors, is biocompatible, bio-inert, injectable, and highly water-soluble, synthesis and degradation are controllable and reproducible, nontoxic	Degrades at high temperature or needs modification	[40, 88]
Polyglycolic acid (PGA)	Biocompatible, biodegradable, cytocompatible, good ductility	Rapid degradation, insolubility	[43, 44]
Polylactic acid (PLA)	Renewable resources, easy production, good biocompatibility, biodegradability, and bioabsorbability, low toxicity, proper mechanical strength, low inflammatory response, transparent, low cost, injectable and compressible	Low hydrophilicity, long-term degradation	[4]
Polylactic-co-glycolic acid (PLGA)	Biodegradable, biocompatible, controllable degradation rate, can serve as a carrier for drugs and tissues, nontoxic	May induce inflammation	[89]
Poly(N-isopropylacrylamide) (PNIPAM)	Thermosensitive, can be used for controlled drug release	Rapid aggregation, requires chemical modification	[50]
Poly(glycolide-co-caprolactone) (PGCL)	Good mechanical strength, biodegradability and biocompatibility, elasticity, proper pore size for drug and cell delivery	N/A	[53]

ECM extracellular matrix