Development of self-assembled phytosterol based nanoassemblies as vehicles for enhanced uptake of doxorubicin to HeLa cells

Nanoscale supramolecular systems have been increasingly gaining importance as drug release vehicles due to their ability to target tumor cells. In this work, we have developed a new class of nanoassemblies derived from the phytosterol 24-EpiBrassinolide (EpiB) for the development of nanocarriers for the anticancer drug Doxorubicin (DOX). EpiB is a biocompatible cholesterol mimic, and has inherent apoptotic properties toward cancer cells. Thus, by encapsulating DOX within a nanocarrier with innate anticancer ability we have developed a targeting system that can enhance the uptake and efficacy of DOX in tumor cells. The nanocarriers were formed by self-assembly of EpiB. The morphologies of assemblies formed were dependent upon the concentration of EpiB used. While at low concentrations, spherical nanoassemblies were formed, at higher concentration, lamellar aggregates with birefringence properties were observed. Our results indicated that the drug loaded nanocarriers showed diffusion controlled release of the drug, and demonstrated antiproliferative effects, cellular uptake and were apoptotic against HeLa cervical cancer cells. Furthermore, EpiB loaded DOX enhanced both apoptosis and uptake into the cell's nuclei. These supramolecular assemblies may have potential applications for enhancing efficacy of chemotherapeutic drugs through passive targeting.