| Alginate | Alginate microspheres prepared by microfluidic technology with different elasticities and microarchitectures,controlled by calcium ion concentrations. | 18, 32 kPa | Elasticity and porosity regulated the fate of encapsulated MSCs through modulation of the nuclear factor-κB pathway | MSCs | 34 |
| Chitosan-hyaluronic acid | Porous chitosan-hyaluronic acid scaffolds of varied stiffness were fabricated using a phase separation method | 1.41–27.7 kPa | Increased matrix stiffness resulted in increased drug resistance of glioblastoma multiforme cells, and elevated expression of drug resistance-,hypoxia-, and invasion-related genes | Glioblastoma multiforme cells | 21 |
| Dynamic protein hydrogels | A Ru2+-mediated photochemical strategy was used to crosslink an aqueous solution of FGR(G-MEP-R)2 into a chemically-crosslinked protein hydrogel | 6–20 kPa | Human lung fibroblasts dynamically responded to changes of hydrogel mechanics in a reversible fashion, regulated by redox state | Human lung fibroblasts | 39 |
| Fibrin-alginate | Mechanical properties were tuneable via calcium chloride crosslinking | 0.6–3.8 kPa | Spreading of MSCs and endothelial cells was a function of alginate crosslinking density | MSCs,
endothelial cells | 22 |
| Hyaluronic acid | Methacrylated hyaluronic acid was synthesized to allow for crosslinking via Michael addition using the crosslinker dithiothreitol | 0.2–4.5 kPa | Human breast cancer cell (MDA-MB-231Br) adhesion, spreading, proliferation and migration were tightly regulated by the hydrogel stiffness | MDA-MB-231Br | 23 |
| Polyacrylamide | Stiffness of polyacrylamide gels was adjusted using different monomer-to-crosslinker formulations | 2–32 kPa | Cytoskeleton assembly and cell morphology were efficiently regulated by substrate stiffness | HeLa cells | 24 |
Poly
(dimethylsiloxane) | Poly(dimethylsiloxane) was used as the base material in which iron particles were embedded to create a magnetorheological elastomer, whose elasticity was controlled by the spacer distances between the magnet and the samples | 10–55 kPa | The softer substrates yielded more organised sarcomeres,and sarcomere formation was positively correlated with the degree of myocyte enrichment when using human-derived induced pluripotent stem cell cardiomyocytes | Human-derived induced pluripotent stem cell cardiomyocytes,
cardiac fibroblasts | 25 |
| Polyurethane | Controlling the crosslinking of tri-block copolymer and polycaprolactone triol yielded polyurethanes of varying elasticity | 45.0–244.8 kPa | Scaffolds with different stiffnesses stimulated the proliferation of different types of cells | 3T3 fibroblasts,
MG63 cells | 26 |
| Silk fibroin | Developed by introducing inert silk fibroin nanofibres within an enzyme crosslinked system of silk fibroin | 9–60 kPa | MSCs differentiated into endothelial, myoblast and osteoblast cells on the different elastic substrates | MSCs | 35 |
| Silk fibroin-collagen | The concentrations of both proteins was changed gradually while maintaining the ratio at 1:7, which resulted in a gradual change in stiffness at a fixed composition | 0.1–20 kPa | High rigidity allowed human MSCs to preserve all-directional spreading with polygonal shape. Soft substrates might not maintain the polygonal shape | Human MSCs | 27 |
| Poly(ether carbonate urethane)urea | Young’s modulus of scaffolds was tuned by adjusting the molecular weight of polydiol (soft segment) as well as the feed ratios of hard molecular segment to soft molecular segment | 2.5–13.4 MPa | Annulus fibrosus-derived stem cells showed strong tendencies to differentiate into various types of annulus fibrosus-like cells depending on the substrate elasticity | Annulus fibrosus-derived stem cells | 36, 102 |
| PEG | Stiffness was adjusted by adding various PEG monomers and the photoinitiator lithium phenyl-2,4,6-trimethylbenzoylphosphinate | 1.5–12.6 kPa | The functional and molecular outputs of adult mouse ventricular myocytes were dependent on the PEG hydrogel stiffness | Adult mouse ventricular myocytes | 28 |
| Poly(L-lactide-co-caprolactone)/poly(L-lactic acid) | Fibre stiffness was controlled by altering the flow rates of the poly(L-lactic acid)-core and poly(L-lactide-co-caprolactone)-shell solutions. | 14.7–2141.7 MPa | Higher stiffness of the aligned fibrous substrates was found to significantly encourage the proliferation and migration of human umbilical artery smooth muscle cells | Human umbilical arterial smooth muscle cells | 29 |
| GelMA hydrogels | Prepared by photocrosslinking methacrylate gelatine and adjusting the stiffness by varying the concentration | 3–180 kPa | PC12 cell viability, adhesion, spreading and average neurite length were influenced by stiffness | PC12 cells | 30 |
| GelMA/PEGDA hydrogels | Prepared by photocrosslinking methacrylate gelatine and adjusting the stiffness with the crosslinker PEGDA | 4, 40 kPa | Increased matrix stiffness promoted osteogenic differentiation of MSCs | MSCs | 31 |
| GelMA/Collagen hydrogels | Prepared by mixing collagen and GelMA to form an interpenetrating network | 2–12 kPa | With the increase of matrix stiffness, the invasion and sprouting of the two cells decreased regardless of fibre content | MDA-MB-231Br and endothelial cells | 32 |
| Alginate/GelMA hydrogels | Prepared by mixing alginate and GelMA | 6–13 kPa | The expression level of MSC osteogenesis markers was enhanced with the increase in the matrix elastic modulus | MSCs | 33 |