Tannic acid-etched PAN/PVP nanofibers loaded with Cu-MOFs enhance antibacterial efficacy and accelerate wound healing

Wound infection represents a prevalent and pressing clinical challenge, resulting in delayed wound healing and severe complications. In this study, a novel wound dressing was fabricated through a combination of electrospinning and acid etching techniques. First, nanofibers were fabricated by blending electrospun polyacrylonitrile/Polyvinylpyrrolidone (PAN/PVP) polymers with copper-based metal organic frameworks (Cu-MOFs). Subsequently, tannic acid was employed to etch the surface sites of Cu-MOFs on the fibers. The obtained nanofibers exhibited a typical porous structure, superior water absorption and gas permeability, with the average water vapor transmission rate was 2170.6 gm^-2day^-1. Additionally, the release behavior of copper ions can be modulated by altering the mass ratio of PVP to PAN, the amount of Cu-MOFs and the use of tannic acid. In vitro antibacterial assays revealed that the antibacterial efficacy of nanofibers increased with the addition of Cu-MOFs, after 48 hours of treatment, the inhibition rates of the nanofibers against E. coli and S. aureus reached over 79.5 % and 90 %, respectively. In vivo experiments demonstrated that these nanofibers alleviated wound inflammation and promoted collagen and angiogenesis, exhibition superior anti-inflammatory and wound-healing effects. The biosafety tests indicated that the nanofibers loaded with 1 % and 3 % Cu-MOFs exhibited good biocompatibility, while the nanofibers loaded with 5 % Cu-MOFs showed slight cytotoxicity. This study provides a novel strategy for the design and fabrication of advanced wound dressings in biomedical applications.