Ethanol-based proliposome delivery systems of paclitaxel for in vitro application against brain cancer cells

In this study the anticancer activity of paclitaxel-loaded nano-liposomes on glioma cell lines was investigated. Soya phosphatidylcholine:cholesterol (SPC:Chol), hydrogenated soya phosphatidylcholine:cholesterol (HSPC:Chol) or dipalmitoylphosphatidylcholine:cholesterol (DPPC:Chol) in 1:1mole ratio were used to prepare ethanol-based proliposomes. Following hydration of proliposomes, the size of resulting vesicles was subsequently reduced to nanometer scale via probe-sonication. The resulting formulations were characterized in terms of size, zeta potential and morphology of the vesicles, and entrapment efficiency of paclitaxel (PX) as well as the final pH of the preparations. DPPC-liposomes entrapped 35-92% of PX compared to 27-74% and 25-60% entrapped by liposomes made from SPC and HSPC formulations respectively, depending on drug concentration. The entrapment efficiency of liposomes was dependent on the lipid bilayer properties and ability of PX to modify surface charge of the vesicles. In vitro cytotoxicity studies revealed that PX-liposome formulations were more selective at inhibiting the malignant cells. The cytotoxicity of PX-liposomes was dependent on their drug-entrapment efficiency. This study has shown PX-liposomes generated from proliposomes have selective activity against glioma cell lines, and the synthetic DPPC phospholipid was most suitable for maximized drug entrapment and highest activity against the malignant cells in vitro.