Preparation, characterization and evaluation of cytotoxic activity of Tamoxifen bound liposomes against breast cancer cell line

Abstract

The goal of this study was to determine whether neutrally or positively charged liposomes encapsulated with tamoxifen could inhibit the proliferation of human breast cancer MCF-7 cell proliferation compared to free tamoxifen by estimating the potential effects of these complexes on the cell death of human breast carcinoma (MCF-7) cell lines. The formulated tamoxifen liposomal conjugate was characterized by analytical techniques to determine its size, size-distribution, thermotropic changes and conformational changes along with possible cytotoxicity towards MCF-7 (breast cancer cell line) in Vitro. The mean particle diameter was estimated to be 64.70±49.75 nm, 73.72±23.8 nm and 119±54.7 nm for blank liposomes, neutral and positively charged liposomes bound tamoxifen, respectively. As tamoxifen is introduced into positive liposomes, it results in noticeable broadening and shift to lower temperature at 135 C compared to the main characteristic endothermic peak (Tm) of pure liposomes that exists at 140C, while the introduction of tamoxifen into neutral liposomes contributes to the disappearance of the main endothermic peak of pure liposomes. FTIR analysis revealed structure changes in vesicles after tamoxifen was incorporated into liposomes. The IC50 value for tamoxifen in the cytotoxic assay with MCF-7 treated cells was 0.34 μg/ml, while tamoxifen-loaded neutrally or positively charged liposomes showed an increase of IC50 value to 119.62 and 101.23 µg /ml, respectively. Current data suggests a new treatment regimen in where free tamoxifen is substituted with liposomal tamoxifen to improve anticancer activity against MCF-7 cancer cell lines.