Optimisation of electrospinning parameters to successfully obtain high ratios of medium chain length polyhydroxyalkanoate in electrospun fibres with drug loading for wound healing applications

Chronic wounds, burns and ulceration of dermal and mucosal tissues are extremely common and can arise for a wide variety of reasons causing extreme pain and reducing patient quality of life. Current treatment regimens involve the use of topical corticosteroids for prolonged treatment periods. Due to issues surrounding the use of topical ointments there is inadequate drug contact with the wound site and non-specific tissue interaction, potentially leading to significant development of fungal infections as a side effect to corticosteroid treatment. Medium chain length (MCL) and short chain length (SCL) polyhydroxyalkanoates (PHAs) may be applicable to optimise material properties for wound dressing applications. Initial work focussed on defining the optimal electrospinning parameters for suitably elastic fibres whilst subsequent work focussed on achieving an optimised dosing of clobetasol propionate (CP) and fluconazole (FLU) for incorporation with the electrospun fibres without detrimentally compromising the properties of the scaffolds for wound healing applications. Physical and mechanical analysis showed that the 80:20 blend of MCL:SCL polymer at an electrospinning solution concentration of 10% (w/v) gave defect-free fibres with the best elastic properties for wound dressing applications. CP and FLU incorporation into the electrospun fibres did not cause any significant decrease in oral mucosal cell viability. Following in vitro wound healing study promising formulations containing 2% and 10% CP and FLU, respectively, were identified.