Melatonin loaded lipid enriched chitosan microspheres – Hybrid dressing for moderate exuding wounds

Abstract

The aim of this study was to develop nanostructured lipid carrier (NLC)-loaded chitosan-based microspheres as innovative dry powder wound dressing, with melatonin incorporated in both, NLC and chitosan matrix of the proposed hybrid system. Melatonin-loaded NLCs were prepared by a hot homogenization technique, while NLC-loaded microspheres were produced by a spray-drying method. To optimize the critical formulation and process parameters for both NLC and hybrid system, a definitive screening design was employed. NLC particle size, hybrid system production yield, particle size, moisture content, and zeta potential were investigated as responses. The optimized hybrid system was characterized by prolonged melatonin release, good flowability and appropriate extent of fluid uptake. In contact with simulated wound fluid, the hybrid system swelled, turning into a hydrogel layer. The presence of lipid nanoparticles attenuated the evaporative water loss showing the potential to provide optimal hydration for moderate exuding wounds. The hybrid system was proven to be biocompatible with skin keratinocytes and fibroblasts and moreover, showed antimicrobial activity against Staphylococcus aureus and S. aureus MRSA strain.