Hybrid Fe3O4-Poly(acrylic acid) Nanogels for Theranostic Cancer Treatment.

Multifunctional nanomedicine integrated with both therapy and diagnostics holds vast potential in cancer treatment. We developed hybrid Fe3O4-poly(acrylic acid) (PAA) nanogels for both drug delivery and magnetic resonance imaging (MRI). Superparamagnetic Fe3O4 nanoparticles were encapsulated inside porous PAA nanogels via an in situ co-precipitation approach. With successive growth of magnetic nanoparticles, the highest magnetization saturation (M(s)) value of the Fe3O4 nanoparticles in the PAA nanogels was determined as 20 emu/g. The resulting hybrid Fe3O4-PAA nanogels showed high drug loading capacity (98%) and sustained drug release in vitro. Cytotoxicity assays and cellular imaging demonstrated that the hybrid nanogels were highly biocompatible and efficiently internalized in human neuroblastoma SH-SY5Y cells. In MRI studies, the hybrid nanogels exhibited an excellent contrast in T2 weighted imaging and a high MRI sensitivity in the tumor site.