Evaluation of in vitro efficacy of docetaxel-loaded calcium carbonate aragonite nanoparticles (DTX-CaCO3NP) on 4T1 mouse breast cancer cell line.

Abstract

Cockle shell-derived calcium carbonate nanoparticles have shown promising potentials as slow drug-releasing compounds in cancer chemotherapy. In this study, we evaluated the in vitro efficacy of docetaxel (DTX)-loaded CaCO3NP on 4T1 cell line. This was achieved by evaluating the following: cytotoxicity using MTT assay, fluorescence imaging, apoptosis with Annexin V assay, cell cycle analysis, scanning (SEM) and transmission electron microscopy (TEM), and scratch assay. Based on the results, DTX-CaCO3NP with a DTX concentration of 0.5μg/mL and above had comparable cytotoxic effects with free DTX at 24h, while all concentrations had similar cytotoxic effect on 4T1 cells at 48 and 72h. Fluorescence and apoptosis assay showed a higher (p<0.05) number of apoptotic cells in both free DTX and DTX-CaCO3NP groups. Cell cycle analysis showed cycle arrest at subG0 and G2/M phases in both treatment groups. SEM showed presence of cellular blebbing, while TEM showed nuclear fragmentation, apoptosis, and vacuolation in the treatment groups. Scratch assay showed lower (p<0.05) closure in both free DTX and DTX-CaCO3NP groups. The results from this study showed that DTX-CaCO3NP has similar anticancer effects on 4T1 cells as free DTX, and since it has a slow release rate, it is a more preferred substitute for free DTX.