Calcium carbonate end capped, folate mediated Fe3O4@mSiO2 core shell nanocarriers as targeted controlled release drug delivery system
Magnetic mesoporous silica nanospheres (MMSN) were prepared and the surface was modified with cancer cell specific ligand folic acid. Calcium carbonate was then employed as acid activated gatekeepers to cap the mesopores of the MMSN, namely, MMSN FA CaCO3. The formation of the MMSN FA CaCO3 was proved by several characterization techniques, viz. transmission electron microscopy, zeta potential measurement, Fourier transform infrared spectroscopy, BET surface area measurement, and UV Vis spectroscopy. Daunomycin was successfully loaded in the MMSN FA CaCO3 and the system exhibited sensitive pH stimuli responsive release characteristics under blood or tumor microenvironment. Cellular uptake by folate receptor (FR) overexpressing HeLa cells of the MMSN FA CaCO3 was higher than that by non folated conjugated ones. Intracellular uptake studies revealed preferential uptake of these nanoparticles into FR positive [FR( HeLa than FR negative [FR( ]A549 cell lines. DAPI stain experiment showed high apoptotic rate of MMSN FA DNM CaCO3 to HeLa cells. The present data suggest that the CaCO3 coating and folic acid modification of MMSN are able to create a targeted, pH sensitive template for drug delivery system with application in cancer therapy.
Journal of biomaterials applications