Characterization of PLGA-PEG Catharanthus roseus Nanoparticles and Assessing its Anticancer Effects in HER2-Overexpressed Breast Cancer Cells

Background: Catharanthus roseus (CR) shows promising anticancer activity. However, there is limited information on its polymeric formulation. Objectives: Therefore, current study aimed to characterize poly(lactic-co-glycolic acid (PLGA) CR nanoparticles and determine its effects on resistant human epidermal receptor 2 (HER2)-overexpressed breast cancer cells. Methods: PLGA-polyethylene glycol (PEG) CR nanoparticles were synthesized using the solvent displacement method and characterized using ultraviolet-visible spectroscopy (UV-VIS), Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering, transmission electron microscopy (TEM), zeta potential, encapsulation efficiency, and drug release experiments. Cytotoxicity was done using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay. Protein expression was done with a gel image analyzer. Cell morphological changes were viewed under phase-contrast microscope. Results: TEM images showed the nanoparticles were spherical and size less than 100 nm. FTIR results indicated encapsulation of CR based on the presence of 3327 cm(-1), 1637 cm(-1), and 1066 cm(-1) peaks. Encapsulation efficiency was > 60% in both formulations. However, pluronic F68 PLGA-PEG CR nanoparticles showed a gradual release of CR compared with polyvinyl acetate (PVAc). The cytotoxicity assay showed that the half-maximal inhibitory concentration of the CR nanoparticles generated with F68 and PVAc was lower (42-58 mu g/mL) on tamoxifen-resistant cells compared with parent cells (99-147 mu g/mL). Further analysis using CR nanoparticles with F68 exhibited downregulation of HER2 expression and induced apoptotic features based on morphological changes. Conclusion: These findings suggest that PLGA-PEG nanoparticles could retain the cytotoxic effects of CR.