1α,25-dihydroxyvitamin D-eluting nanofibrous dressings induce endogenous antimicrobial peptide expression.

Aim: The aim of this study was to develop a nanofiber-based dressing capable of local sustained delivery of 1 alpha,25-dihydroxyvitamin D-3 (1,25(OH)(2)D-3) and augmenting human CAMP induction. Materials & methods: Nanofibrous wound dressings containing 1,25(OH)(2)D-3 were successfully prepared by electrospinning, which were examined in vitro, in vivo and ex vivo. Results: 1,25(OH)(2)D-3 was successfully loaded into nanofibers with encapsulation efficiency larger than 90%. 1,25(OH)(2)D-3 showed a sustained release from nanofibers over 4 weeks. Treatment of U937 and HaCaT cells with 1,25(OH)(2)D-3-loaded poly(epsilon-caprolactone) nanofibers significantly induced hCAP18/LL37 expression in monocytes and keratinocytes, skin wounds of humanized transgenic mice and artificial wounds of human skin explants. Conclusion: 1,25(OH)(2)D-3 containing nanofibrous dressings could enhance innate immunity by inducing antimicrobial peptide production.