"Trojan Horse"-Inspired Bionic Coating of Mesh-Like Assembled Lysozyme Nanofibers for Anti-Infection, Anti-Oxidative Stress and Bone Repair.

Bacterial biofilm infection and sustained oxidative stress response seriously affect the osseointegration of bone implants. Here, this study developed a bioactive Mg2+ loaded tannic acid (TA)/lysozyme amyloid protein fiber (LAPF) composite antioxidative coating to enhance antibacterial, antioxidative and pro-osteogenic functions of bone implants. Inspired by "Trojan horse", the mesh-like TA/LAPF coatings exhibited good antibacterial properties, significantly inhibiting the formation of bacterial biofilms. Interestingly, the TA/LAPF coatings cleared 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) free radicals obviously (scavenging rate of 83.46 ± 1.43%), and inhibited intracellular reactive oxygen species (ROS) of bone marrow mesenchymal stem cells (BMSCs) under an oxidative stress environment. In addition, the biomimetic LAPF coatings exhibited good blood compatibility, promoting the migration of human umbilical vein endothelial cells (HUVECs) and angiogenesis effectively. Notably, the (TA/LAPF)8+Mg2+coatings could effectively improve early adhesion of BMSCs, and exhibited both great in vitro alkaline phosphatase (ALP) activity and osteogenic mineralization. In 6-week implantation experiments, Mg2+ loaded TA/LAPF coating significantly inhibited in vivo bacterial growth and promoted bone regeneration. The biomimetic mesh-like coatings of antibacterial protein-based nanofiber provide important guidance for the design of anti-infection scaffolds in surface engineering of bone repair.