Thiolation-Based Protein-Protein Hydrogels for Improved Wound Healing

Abstract The limitations of protein-based hydrogels, including their insufficient mechanical properties and restricted biological functions, arise from the highly specific functions of proteins as natural building blocks. A potential solution to overcome these shortcomings is the development of protein-protein hydrogels, which integrate structural and functional proteins. In this study, we introduce a protein-protein hydrogel formed by crosslinking bovine serum albumin (BSA) and a genetically engineered intrinsically disordered collagen-like protein (CLP) through Ag-S bonding. Our approach involves thiolating lysine residues of BSA and crosslinking CLP with Ag + ions, utilizing thiolation of BSA and the free-cysteines of CLP. The resulting protein-protein hydrogels exhibit exceptional properties, including notable plasticity, inherent self-healing capabilities, and gel-sol transition in response to redox conditions. Furthermore, in comparison to standalone BSA hydrogels, these protein-protein hydrogels demonstrate remarkable antibacterial properties, enhanced cellular viability, and improved cellular migration. In vivo experiments provide conclusive evidence of accelerated wound healing, observed not only in murine models with streptozotocin (Step)-induced diabetes but also in zebrafish models subjected to UV-burn injuries. Detailed mechanistic insights, combined with assessments of pro-inflammatory cytokines and the expression of epidermal differentiation-related proteins, robustly validate the protein-protein hydrogel’s effectiveness in promoting wound repair. This pioneering approach advances the development of protein-protein hydrogels and serves as a reference for the creation of multifunctional protein-based hydrogels.