Polypeptide-engineered physical hydrogels designed from the coiled-coil region of cartilage oligomeric matrix protein for three-dimensional cell culture

Photo-cross-linkable physical hydrogels based on the coiled-coil region of the cartilage oligomeric matrix protein and polyethylene glycol diacrylate were designed and synthesized to mimic the natural extracellular matrix for three-dimensional cell culture. The engineered polypeptides (Pcys and RGDPcys) were modified with polyethylene glycol diacrylate to form photo-cross-linkable multifunctional macromers via the Michael-type addition reaction between the cysteine residues and acrylates. Gel formation was confirmed by rheological measurements. The swelling ratio and stability of 10% w/v RGDP-PEGacrylate6k hydrogel were 38% and 15 days, respectively. Spreading and migration of encapsulated fibroblast cells were observed in these physical hydrogels, while round cells were observed in a covalent control hydrogel. In addition, rapid self-healing of these physical hydrogels can provide a flexible way to build tissue by self-assembly and bottom-up approach. The results demonstrate that such physical hydrogels are expected to have great potential applications in tissue engineering.