Synthesis, Characterization, and In Vitro Evaluation of Super Paramagnetic Nanoparticles Grafted with PAMPS for Controlled Delivery of Cationic Drugs

The pH-sensitive poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPS) grafted Fe3O4 nanoparticles (NPs), as the polyanionic nanocarriers, were synthesized and characterized by Fourier transform-infrared (FTIR) spectroscopy, energy-dispersive X-ray spectroscopy (EDS), dynamic light scattering (DLS), thermo-gravimetric analysis (TGA) and vibrating sample magnetometry (VSM). The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images were used to explore the shape, morphology and size of the NPs. Doxorubicin (Dox), an anticancer agent as the model drug, was successfully loaded on the synthesized NPs. The Dox-loaded NPs exhibited different release profiles at various pH values. For example, the cumulative Dox release at pH 5.5 was about 2.6 times higher than that at pH 7.4. The cytotoxicity of the synthesized NPs with or without Dox were investigated in the vicinity of the human adipose derived mesenchymal stem cells (hADSCs) and HeLa cells using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay and the AO/EB (acridine orange/ethidium bromide) staining method.