Preparation and characterization of withaferin A loaded pegylated nanoliposomal formulation with high loading efficacy: In vitro and in vivo anti-tumour study

Abstract

Withaferin A (WA) is a natural steroidal lactone with promising therapeutic applications. However, its clinical application is limited due to the low bioavailability and hydrophobic nature. In this study, we had prepared PEGylated nanoliposomal withaferin A (LWA) using thin-film hydration method. Dynamic light scattering, Transmission electron microscopy, and HPLC were used to investigate the impact of prepared formulations on the size, charge, morphology, and encapsulation efficiency of the LWA. The prepared nanoliposomal system had spherical vesicles, with the mean particle size of 125 nm and had an encapsulation efficiency of 83.65% with good stability. The characterization results indicated that nanoliposomal formulation is able to improve biocompatibility and bioavailability of WA. In vitro drug release study showed that LWA had an enhanced sustained drug release effect than the free drug. In vitro studies using ascites cell lines (DLA and EAC) showed that LWA treatment could induce apoptosis in ascites cells evidenced by acridine orange/ethidium bromide, Hoechst, and Giemsa staining. In vivo tumour study revealed that LWA treatment significantly reduced tumour growth and improved survival in DLA tumour bearing mice. In vivo results further demonstrated that LWA mitigated solid tumour development by regulating Ki-67 and cyclin D1 protein expression. The overall study results reveal that nanoliposome encapsulated WA exhibits therapeutic efficacy over WA in regulating tumour development as evidenced from ascites cell apoptosis as well as experimental tumour reduction studies.

Keywords: Apoptosis; DLA; EAC; Nanoliposomes; Withaferin A.