Table 1.

Polymers commonly used in various hydrogel formulations.

Natural Polymer	Synthetic Polymer	Hybrid Polymer
Hyaluronic acid	PEG-PLA-PEG	P (PEG-co-peptides)
Pectin	PEG-PLGA-PEG	P-(HPMA-g-peptide)
Alginic acid	PEG-PCL-PEG	P (PLGA-co-serine)
Carrageenan	PLA-PEG-PLA	Alginate-g-(PEO-PPO-PEO)
Chondroitin sulphate	PHB	HA-g-NIPAAm
Dextrin sulphate	P (PEG/PBO terephthalate)	Collagen-n-acryl ate
Chitosan	Polyurethane	Alginate-acryl ate
Polylysine	Polyimide
Collagen (and gelatine)	Polyvinylpyrrolidone
Carboxy methylchitin	Polyvinyl alcohol
Fibrin and silk fibroin	Polyacrylate
Dextrin	Polythene oxide
Pullulan	Polymethacrylate
Agarose Elastin Glycosaminoglycans Decellularized Hydrogels