Diabetic chronic wounds remain a major clinical challenge due to persistent infection, excessive inflammation, and impaired tissue regeneration. Herein, we report a multifunctional peptide-based antibacterial hydrogel (PAHG) for treating infected wounds, constructed through the incorporation of Cys-Arg-NH2 (CR)-Ag nanoassemblies into a bioactive matrix. In this design, the CR dipeptide enables in situ reduction and stable coordination of silver ions, yielding CR-Ag nanoassemblies with controlled silver release and enhanced biocompatibility. Co-assembly of this antibacterial component with chitosan, gelatin, collagen, and epidermal growth factor (EGF) affords a three-dimensional hydrogel network that provides a moist wound microenvironment, structural support, and sustained release of pro-regenerative cues. The resulting PAHG system exhibits excellent antibacterial activity against Escherichia coli and methicillin-resistant Staphylococcus aureus, with inhibition efficiencies exceeding 80%, while maintaining high cytocompatibility with human skin fibroblasts (∼150% viability). In a diabetic infected wound model, PAHG significantly accelerates wound healing, achieving nearly complete closure within 12 days, accompanied by enhanced collagen deposition and no noticeable histopathological abnormalities in major organs. By integrating molecularly engineered antibacterial nanoassemblies with rationally designed multicomponent hydrogels, this work provides a promising strategy for the development of bio-based antimicrobial materials and chronic wound dressings.
Heng Ge, Wen Yuan, Yulin Sun et al.· Journal of materials chemist...· 0 citations
The accumulation of poly(ethylene terephthalate) (PET) waste in the environment poses a severe ecological threat. While extensive research has focused on high-performance PET degradation by thermophilic enzymes, PET hydrolases are efficient under lower-temperature conditions, which would better align with green and energy-saving demands the energy-efficient centralized treatment of PET waste remains underexplored. Herein, based on our previously engineered mesophilic IsPETaseS121P/D186A, we performed rational design to improve its PET degradation activity at relatively low temperature. Through rational design methods including salt bridge construction and hydrophobic engineering, we obtained effective variant PADFL (IsPETaseS121P/D186A/N246D/Y87F/N233L), demonstrating an 8.37-fold activity of IsPETaseS121P/D186A in PET degradation efficiency (56.52-fold of IsPETase). Molecular dynamics (MD) simulations further revealed stronger PET binding affinity, enhanced hydrogen bonding network, and reduced acylation energy barrier. Overall, this work enhances the degradation activity of the PET hydrolase through energy-based rational design and obtained optimized variant PADFL, offering a promising candidate for future efficient PET degradation under mild temperature conditions.