In vitro evaluation of Aurora kinase inhibitor—VX680—in formulation of PLA-TPGS nanoparticles

Polymeric nanoparticles prepared from poly(lactide)-tocopheryl polyethylene glycol succinate (PLA-TPGS) were used as potential drug carries with many advantages to overcome the disadvantages of insoluble anticancer drugs and enhance blood circulation time and tissues. VX680 is an Aurora kinase inhibitor and is also the foremost Aurora kinase inhibitor to be studied in clinical trials. In this study, we aimed to investigate whether VX680-loaded PLA-TPGS nanoparticles (VX680-NPs) are able to effectively increase the toxicity of chemotherapy. Accordingly, we first synthesized VX680-loaded nanoparticles and NP characterizations of morphology, mean size, zeta potential, and encapsulation efficiency were spherical shape, 63 nm, −30 mV and 76%, respectively. Then, we investigated the effects on HeLa cells. The cell cytotoxicity was evaluated by the xCELLigence real-time cell analyzer allowing measurement of changes in electrical impedance on the surface of the E-plate. Analysis of nucleus morphology and level of histone H3 phosphorylation was observed by confocal fluorescence scanning microscopy. Cell cycle distribution and apoptosis were analyzed by flow cytometry. Our results showed that VX680-NPs reduced cell viability with IC₅₀ value lower 3.4 times compared to free VX680. Cell proliferation was inhibited by VX680-NPs accompanied by other effects such as high abnormal changes of nucleus, a decrease of phospho-histone H3 at Ser10 level, an increase of polyploid cells and resulted in higher apoptotic cells. These results demonstrated that VX680-NPs had more cytotoxicity than as treated with VX680 alone. Thus, VX680-NPs may be considered as promising drug delivery system for cancer treatment. (paper)