Super-magnetic smart hybrid doxorubicin loaded nanoparticles effectively target breast adenocarcinoma cells

A facile straightforward eco-friendly approach for the preparation of super-paramagnetic, thermo-responsive inorganic/organic hybrid nanoparticle system is described: several super-paramagnetic Fe3O4 nanoparticle clusters into silica shell using sol-gel process tailoring the silica shell thickness ∼40 nm. Use of poly (N-isopropylacrylamide-co-N-vinylimidazole-co-Acrylic acid) (PNIBIM-AA) polymer acts as specific structure directing agent, which covalently linked with silica-magnetic core via free-radical polymerization; leads directly to core-shell-corona hybrid nano-carrier system. Functional properties such as uniformity in size, pH and magnetic momentum are achieved. Effect of temperature/pH dependent bi-phasic (burst initial followed by sustain) release of model chemotherapeutic molecule Doxorubicin on MCF7 (breast adenocarcinoma cells from human) is investigated comprehensively including MTS assay, calcein AM/ethidium bromide assay and actin filament arrangements. DOX-loaded MNP/MSN/p-NBIM-AA (concentration range 50–1000 μg/ml) induces dose-dependent cytotoxicity in response to released DOX. Untreated viable cells become green upon hydrolysis of intra cellular esterases activity with well stretched actin filament compared to treated dead red colored round cells. Taken together, the designed nano-carrier is a potential multifunctional delivery platform for therapeutic applications.