Tunable Protein Hydrogels: Present State and Emerging Development.

In recent years, protein and peptide-based hydrogels have received great attention for applications in biomedicine. Compared to hydrogels based on synthetic materials, they have the decisive advantages of being biological origin, providing cells with a more in vivo-like microenvironment and possessing potential biological activity. Empowered by the steadily deepened understanding of the sequence-structure-function relationship of natural proteins and the rapid development of molecular-biological tools for accurate protein sequence editing, researchers have developed a series of recombinant proteins as building blocks and responsive blocks to design novel functional hydrogels. The use of multi-block design further expands the customizability of protein hydrogels. With the improvement of standardization of preparation and testing methods, protein hydrogels are expected to be widely used in medical treatment, skin care, artificial organs and wearable electronic devices. More recently, the emergence of catalytically active protein hydrogel brings new opportunities for applications of protein hydrogels. It is believed that through integrated approaches of engineering biology and materials sciences novel and hereto unthinkable protein hydrogels and properties may be generated for applications in areas beyond medicine and health, including biotechnology, food and agriculture, and even energy.