Copper-based polymer-metal-organic framework embedded with Ag nanoparticles: Long-acting and intelligent antibacterial activity and accelerated wound healing

Herein, we provided a novel copper-based polymer-metal-organic framework (polyCu-MOF) as an efficient scaffold for loading silver nanoparticles (denoted as polyCu-MOF@AgNPs), which was applied as a superior antibacterial agent for wound healing. PolyCu-MOF was prepared by using the polyether ligand containing 1,4-benzenedicarboxylic acid (H2BDC) unit as building block, 4,4 & PRIME;-bipyridine as co-ligand, and copper ions as coordination centers. Given that polyCu-MOF comprised an ultrathin nanosheet-like structure, abundant carboxyl moieties, and structure defects and possessed large specific surface area and high porosity, large amounts of Ag ions were adsorbed in the polyCu-MOF network, forming polyCu-MOF@AgNPs hybrid after reduction by NaBH4. Compared with the Cu-MOF@AgNPs hybrid, in which Cu-MOF was synthesized using H2BDC as ligand, the polyCu-MOF@AgNPs hybrid contained lower density of copper nodes and higher loading amount of Ag NPs, thereby showing lower released amount of Cu2+ ions and higher released amount of Ag+ ions, enhancing biocompatibility, and decreasing hemolysis. In vitro experiments showed that polyCu-MOF@AgNPs efficiently killed bacteria through damaging cell integrity caused by the production of reactive oxygen species and disruption of bacterial metabolism. Furthermore, in vivo experiments revealed that polyCu-MOF@AgNPs improved the healing efficiency of bacteria-infected wound because of the synergistic antibacterial effect, promoting skin regeneration and dense collagen deposition. The present work can provides an effective antibacterial platform based on polymer-MOF and extends great potential applications of MOFs in wound healing.