A review of protein hydrogels: Protein assembly mechanisms, properties, and biological applications

In the past few years, protein hydrogels have attracted more and more attention due to their unique physical, chemical and biological properties. They have a more complex molecular structure than traditional polymer hydrogels, which leads to special properties like excellent biocompatibility, biodegradability and responsiveness. The proteins used to construct hydrogels have similar structure and function with proteins in human body, which is an excellent bio-derived material with potential biological activities. Therefore, through the study of the flexible and diverse assembly mechanism of protein hydrogels, we can understand their special properties. This allows it to be used to construct rich and diverse biomaterials with a wide range of application prospect. In this review, we summarized the research progress of protein hydrogels. The different assembly mechanisms were briefly described, including self-assembly and co-assembly. Then we introduced properties based on protein, including responsiveness, adhesion property, biocompatibility, conductivity, self-healing and mechanical property. In addition, the applications of protein hydrogels in wound dressings, drug delivery, bioadhesion, and biosensing were reviewed. Finally, we summarized the current challenges in the field of protein hydrogels. The future development prospects in biomedicine, tissue repair, biosensing and so on were also prospected.