Table 1.
Representative materials that can be used for 3D cell culture studies
| Materials | Gelation method | Featured properties | Ref. |
|---|---|---|---|
| Natural‐derived materials | |||
| Collagen | Raising the temperature and the pH can initiate collagen fibril self‐assembly |
Fibrous structure Exhibits structural and mechanical properties (strain‐stiffening) reminiscent of native tissues Displays native cell adhesion ligands |
[[qv: 24,26b,41,51b]] |
| Fibrin | Thrombin can initiate self‐assembly of insoluble polypeptide chains of fibrinogen into a fibrillar network |
Fibrous structure Enzymatically degradable Strain‐stiffening property |
30, 93 |
| Gelatin | Gelatin gel can be formed by lowing the temperature or photo‐cross‐linking (for methacrylated gelatin, GelMA) |
Stiffness can be controlled Enzymatically degradable |
94 |
| Alginate | Alginate hydrogels can be formed by cooperative binding with divalent cations such as Ca2+ or Ba2+ |
Should be functioned with adhesive proteins for cell adhesion and spreading Stress‐relaxation property |
[[qv: 6b,47,95]] |
| Hyaluronic acid | Modified HA can form gels by photo‐cross‐linking or enzymatically cross‐linking | It contains a high degree of chemical modification that enables considerable tunability | 45, 96 |
| Chitosan | Gels can be formed by adjusting the pH | Excellent biocompatibility and immunostimulatory activities | 97 |
| Dextran | Dextran gels can be formed by chemically cross‐linking |
Commercially available Cross‐linked dextran can act as a microcarrier |
98 |
| Agarose | Cooling initiates the aggregation of double helices by the entanglement of anhydro bridges |
Tunable elastic moduli Viscoelastic properties |
99 |
| Matrigel | Gels can be formed irreversibly and rapidly between 24 and 37 °C |
Gelling speed depends on the concentration and gelation temperature A heterogeneous composition |
100 |
| Synthetic materials | |||
| Polyethylene glycol (PEG) | PEG gels can be formed under both physiological pH and temperature | Can be engineered to present different adhesive ligands and to degrade via passive, proteolytic, or user‐directed modes | 87 |
| Poly(vinyl alcohol) (PVA) | Modified PVA can form gels under photo‐cross‐linking | Satisfactory biocompatibility and sufficient mechanical properties | 101 |