Preparation, characterization, and anticancer effects of simvastatin-tocotrienol lipid nanoparticles

Previously it was shown that combined low dose treatment of tocotrienols and statins synergistically inhibited the growth of highly malignant +SA mammary epithelial cells in culture. Therefore, the objective of the present work was to prepare and characterize lipid nanoparticles that combined simvastatin and tocotrienol rich fraction (TRF) as potential anticancer therapy. The entrapment of simvastatin in the oily nanocompartments, which were formed by TRF inclusion into the solid matrix of the nanoparticles, was verified by its high entrapment efficiency and the absence of endothermic or crystalline peaks when blends were analyzed by DSC and PXRD, respectively. The release of simvastatin from the nanoparticles in sink conditions was characterized by an initial burst release of approximately 20% in 10 h followed by a plateau. No significant change in particle size (similar to 100 nm) was observed after storage for six months. The anticancer activity of the nanoparticles was verified in vitro by observing their antiproliferative effects on malignant +SA mammary epithelial cells. The IC50 of the reference alpha-tocopherol nanoparticles was 17.7 mu M whereas the IC50 of the simvastatin/TRF nanoparticles was 0.52 mu M, which confirmed the potency of the combined treatment and its potential in cancer therapy. (C) 2010 Elsevier B.V. All rights reserved.