Triple-responsive drug nanocarrier: Magnetic core-shell nanoparticles of Fe3O4@poly(N-isopropylacrylamide)-grafted-chitosan, synthesis and in vitro cytotoxicity evaluation against human lung and breast cancer cells

Herein, synthesis, characterization and cytotoxicity evaluation of core-shell nanoparticles of magnetic Fe3O4-poly(N-isopropylacrylamide) (PNIPAAm) grafted with chitosan, as magnetic field, pH and temperature responsive nanocarrier for targeted delivery of anticancer drug is reported. PNIPAAm and chitosan are respectively, served as thermo- and pH-responsive moieties. The chemical structure, morphology and magnetic properties of materials are confirmed via Fourier transform infrared (FT-IR) spectroscopy, vibrating sample magnetization (VSM), thermal gravimetric analysis (TGA), field emission-scanning electron microscopy (FE-SEM), energy dispersive X-ray analysis (EDX) and dynamic light scattering (DLS) measurements. The core-shell structure and size of final nanoparticles were confirmed by transmission electron microscopy (TEM) as 85 nm. The nanocarrier have exhibited 94% drug entrapment efficiency and 32% drug loading capacity for methotrexate (MTX) as an anticancer drug, and an enhanced antitumor activity against A549 and MCF7 cell lines compared to free MTX in in vitro cytotoxicity assay. The highest MTX release has been observed at 40 °C and pH = 5.5 which is very similar to cancerous cell conditions, proving capability of nanocarrier in targeted drug delivery. In addition, DAPI staining and MTT assay tests confirmed effective anticancer performance of MTX-loaded nanocarrier. In conclusion, synthesized nanocarrier can be successfully employed for targeted drug delivery to cancerous tissues.