Novel biodegradable sandwich-structured nanofibrous drug-eluting membranes for repair of infected wounds: an in vitro and in vivo study

Background: The purpose of this study was to develop novel sandwich-structured nanofibrous membranes to provide sustained-release delivery of vancomycin, gentamicin, and lidocaine for repair of infected wounds. Methods: To prepare the biodegradable membranes, poly(D, L)-lactide-co-glycolide (PLGA), collagen, and various pharmaceuticals, including vancomycin, gentamicin, and lidocaine, were first dissolved in 1,1,1,3,3,3-hexafluoro-2-propanol. They were electrospun into sandwich-structured membranes with PLGA/collagen as the surface layers and PLGA/drugs as the core. An elution method and a high-pressure liquid chromatography assay were used to characterize in vivo and in vitro drug release from the membranes. In addition, repair of infected wounds in rats was studied. Histological examination of epithelialization and granulation at the wound site was also performed. Results: The biodegradable nanofibrous membranes released large amounts of vancomycin and gentamicin (well above the minimum inhibition concentration) and lidocaine in vivo for more than 3 weeks. A bacterial inhibition test was carried out to determine the relative activity of the antibiotics released. The bioactivity ranged from 40% to 100%. The nanofibrous membranes were functionally active in treating infected wounds, and were very effective as accelerators in early-stage wound healing. Conclusion: Using the electrospinning technique, we will be able to manufacture biodegradable, biomimetic, nanofibrous, extracellular membranes for long-term delivery of various drugs.