Electrospun miRNA-21@doxycycline core-sheath nanofibers for a synergistic treatment of diabetic wounds

In this paper, core-sheath nanofiber membrane (miRNA-21@DCH) co-loaded with microRNA-21 and doxycycline (DCH) was prepared by coaxial electrospinning technology for the treatment of diabetic wounds. DCH could inhibit the growth of Gram-negative and Gram-positive bacteria that easily cause infection at the wound site, thus promoting the epidermal layer thickening and dermal connective tissue hyperplasia. The cumulative release rate of DCH was 89 % after 72 h. In vitro antibacterial experiments at 24 h showed that the bacteriostatic zone diameter of miRNA-21@DCH nanofiber membrane was about 3.82 cm for Escherichia coli and 4.54 cm for Staphylococcus aureus , indicating that miRNA-21@DCH nanofiber membrane had good antibacterial effect. The microRNA-21 could promote angiogenesis and collagen deposition at the wound site, providing a favorable growth environment for tissue cell proliferation. The synergistic effect of DCH and microRNA-21 confers miRNA-21@DCH core-sheath nanofiber membrane the advantage of rapid healing of diabetic wounds. After 16 days treatment with miRNA-21@DCH nanofiber membrane, the wound basically healed and the wound surface was smooth. In addition, in vitro cytotoxicity assays showed that miRNA-21@DCH nanofiber membrane had good biocompatibility. The prepared miRNA-21@DCH nanofiber membrane provides a new and effective strategy for the synergistic treatment of diabetic wounds.