Nitrofurazone-loaded electrospun PLLA/sericin-based dual-layer fiber mats for wound dressing applications

The ideal wound dressing should achieve rapid healing with hemostasis, antimicrobial activity, maintenance of a moist wound bed, etc. The electrospun blend mat meets the requirements outlined for wound healing, by their microfibrous structures providing a suitable environment for wound healing. In this study, a dual-layer nanofiber blend mat wound dressing of nitrofurazone (NFZ)-loaded poly(L-lactide) (PLLA)/sericin nanofibers and NFZ-loaded PLLA nanofibers is fabricated by electrospinning. The NFZ-loaded PLLA/sericin nanofibers act as the first layer and then the NFZ-loaded PLLA nanofibers are the second layer to prepare the dual-layer fiber dressings. The prepared dual-layer NFZ-loaded fiber dressings have satisfactory antibacterial activity against both Gram-positive and Gram-negative bacteria. In vitro drug release studies show that the drug release profiles can be controlled by adjusting the drug amount in different layers of the dual-layer dressings. The methyl thiazolyl tetrazolium (MTT) assays demonstrate that the NFZ-loaded PLLA/sericin fibers are nontoxic and biocompatible. In vivo wound healing tests are performed in rats. The results reveal that the dual-layer fiber dressings perform better than commercial non-woven dressing in decreasing wound size. It is observed at 12 days that the wound size reduction is 97% for being dressed with the dual-layer fiber dressings but 84% for the commercial woven dressing. These NFZ-loaded PLLA/sericin‖PLLA dual-layer fiber mats may provide a promising candidate for accelerating wound healing.