Table 2.

Summary of synthetic hydrogels suited for organoid culture.

Hydrogels	Origin	Advantages	Disadvantages	Gelation	Organoid types	Refs.
PEG	Artificially synthesized	•Biodegradability •Biocompatibility •Good water solubility •Physiological inertia •Wide range of size distribution, adjustable arm length and controllable molecular weight •Easy to be modified	•Low cell adhesion •Lacks of bioactivity •Lacks of the intricate nonlinear mechanical properties	•Physical gelation: Electrostatic adsorption •Chemical gelation: Photopolymerization, click chemistry, radical polymerization	•hHSPC-derived bone marrow organoids •Primary human intestinal enteroids and endometrial organoids •IPSC-derived liver organoids	[[129], [130], [131], [132],134,135]
PIC	Artificially synthesized	•Thermosensitive (the gelation temperature around 18 °C) •Ultra-response to mechanical stress (i.e., strain-stiffening property)	•Poor biodegradability	•Physical gelation: Thermal self-assembly •Chemical gelation: Click chemistry	•Human Liver Organoid •Mammary Gland Organoid	[136,137,178]
PAAM	Artificially synthesized	•Eastic modulus is easy to control	• Relatively chemically inert and lacks cell adhesion sites	•Acrylamide (AAm) and bisacrylamide (BAAm) were copolymerized by free radical polymerization in aqueous solution •Micellar copolymerization methodology	•Cardiovascular organoids	[140,179]
PVA	Artificially synthesized	•Low toxicity •High hydrophilicity •Good mechanical properties (i.e., high elastic modulus and high mechanical strength)	• Lacks of cell adhesion sites	•Physically gelation: Freeze-thawing •Chemical gelation: PEG-link, epichlorohydrin, boric acid, aldehydes, and heavy metal compounds •Radiation gelation: Gamma-ray, electron beams, and X-ray	•Pancreas organoids	[28,180]