Impact of Biocompatible Poly(ethylene glycol)-block-Poly(ε-caprolactone) Nano-Micelles on the Antifungal Efficacy of Voriconazole

Abstract

This study aimed to encapsulate voriconazole into nano-micelles of poly(ethylene glycol)-block-poly(ε-caprolactone) to enhance its antifungal activity and reduce the required doses. The nano-micelles were prepared at various drug/polymer ratios, and their various physicochemical properties were studied. The nano-micelles had a small particle size in the range of ~50-60 nm and homogenous size distribution. The nano-micelles had high encapsulation efficiency and loading capacity in the range of ~40-95% and ~20-27%, respectively. Both encapsulation efficiency and loading capacity could be modulated by changing the drug/polymer ratio. Voriconazole release from the nano-micelles was much slower than the drug solution. The drug release pattern was biphasic, with a relatively faster initial phase followed by a sustained release. The antifungal efficacy was evaluated in vitro against Aspergillus flavus and Candida albicans using the drug solution in dimethyl sulfoxide/water as a control. The inhibition zone diameters of the fungi increased with increasing the drug concentration. The diameter of the inhibition zones against Aspergillus flavus was comparable for the nano-micelles and control. In contrast, the nano-micelles had significantly wider inhibition zones against Candida albicans than the control. These results show that poly(ethylene glycol)-block-poly(ε-caprolactone) nano-micelles could be used as a promising delivery system to enhance voriconazole antifungal efficacy.