Design of functional hydrogels using smart polymer based on elastin-like polypeptides

Elastin-like polypeptides (ELPs) are genetically encoded materials that enable the bottom-up design and manufacture of functional biomaterials. Here, we report the design and synthesis of a lysine-rich ELPs modified with methacrylate groups, giving rise to temperature-induced phase transition and photo-crosslinking capabilities. The degree of methacrylate functionalization could be varied by changing the reactant ratio of N-succinimidyl methacrylate (NHS-MA) to ELPs. The prediction of the structural transition with increasing temperature was validated using integrated experimental and simulation approaches. Combined with hydrogel fabrication strategy, methacrylated ELPs (ELP-MA) can be engineered into different physical forms like coacervates and hydrogels, which further function as light transmittance regulator and elastic adhesives. In addition, physical properties of the hydrogels such as mechanical strength, pore size, and swelling ratio could be controlled by the methacrylation degree and ELP-MA concentration. Subcutaneous implantation in mice showed that the resulting ELP-MA hydrogels exhibited a good biocompatibility. Our biological and chemical engineering approaches to creat functional materials of the ELP-MA will be useful to design various smart materials in the future.