preparation of dissolving microneedle with the backing layer of electrospun nanofibers for wound healing acceleration

Aim and background: wound healing is a complicated physiological process that requires an appropriate environment to encourage healing process. herein, we develop a novel dissolving microneedle (mn) patch with electrospun nanofibers backing layer that can perform transdermal delivery and combination therapy for wound healing. nanofibrous scaffold combined of poly (vinyl alcohol) and gelatin loaded with taurine and bismuth nanoparticles was prepared by electrospinning method, called pgtbi. the needle of the mn, called pha, was composed of poly methyl vinyl ether-alt-maleic acid, hyaluronic acid and allantoin. methods: the pgtbi-pha mn patches were fabricated via a molding method in a two-step casting process. characterization experiments of bi2s3 nanoparticles (nps), nanofibrous scaffolds and mn patches were performed to confirm their structure. to evaluate the photothermal effect of bi2s3 nps, different concentrations of bi2s3 nps were irradiated by 808 nm nir laser for 10 min. the mechanical properties of nanofiber mats were investigated. in vivo and in vitro insertion test using trypan blue and parafilm were performed on mn patches.results and discussion: tem image, zeta potential and elemental analysis indicated successful synthesis of bi2s3 nps. the temperature of bi2s3 nps increased by about 50.4 °c at a concentration of 200 μg/ml after irradiation for 10 min, which is the temperature required to kill bacteria, indicating the excellent photothermal performance of bi2s3 nps. investigation of tensile tests showed that young s modulus of the nanofiber mats was 168.4 mpa, which was in the skin range. parafilm and skin insertion tests show that the pgtbi-pha mn patches have sufficient strength to penetrate the skin and successfully release their contents after dissolution.conclusion: we have developed a novel multifunctional pgtbi-pha mn patch to provide targeted therapy for wound healing and skin tissue regeneration.