An in vitro cytotoxicity of a novel pH-Sensitive lectin loaded-cockle shell-derived calcium carbonate nanoparticles against MCF-7 breast tumour cell

The acidic microenvironment of tumour cells requires a pH-sensitive delivery mechanism for improving drug release. In this study, we investigated the feasibility of using pH-sensitive ACC nanoparticles with sustained-release performance and slow degradability as carriers for lectins isolated from edible mushroom Agaricus bisporus (ABL) that exhibited anti-proliferating effects on tumour cells. ABL was purified and characterized using ion-exchange, gel filtration chromatography, sodium dodecyl sulfate-polyacrylamide gel electrophoresis and mass spectrometry. ABL-ACC nanoparticles were synthesized through a simple precipitation process coupled with mechanical grinding. The conjugated ABL-ACC-NPs were characterized using Fourier-transform infrared spectroscopy, X-ray powder diffraction, scanning electron microscope, transmission electron microscope and zeta potential. Cytotoxicity of ABL-ACC-NPs was analyzed using methylthiazol tetrazolium assay against MCF-7 cells compared with ABL and ACC-NPs. The results indicated biostability of ACC-NPs and low toxicity toward MCF-7 cells, and induced increased reduction in MCF-7 viability compared with ABL. ABL-ACC-NPs-FITC showed fully internalization and accumulation inside the nucleus comparing with ABL-FITC which showed only accumulation around the nuclear envelope. Inclusively, conjugation of ABL with ACC-NPs has improved its cytotoxicity, enhanced its bioavailability, internalization into the tumour cells, accumulation in cell organelles which may promote cell responses and subsequently triggered cell death.