Synthesis and functionalization of polypyrrole-Fe3O4 nanoparticles for applications in biomedicine

Superparamagnetic Fe3O4 particles are successfully encapsulated inside polypyrrole (PPY) via emulsion polymerization using polyvinyl alcohol as a surfactant. The thus-obtained PPY-Fe3O4 nanoparticles have distinct spherical shape and size (80-100 nm in diameter) and are superparamagnetic with high magnetization values and good electrical conductivities. By varying the starting Fe3O4 : pyrrole monomer mass ratio, nanoparticles with varying Fe3O4 content can be synthesized. These nanoparticles are also cyto-compatible, and due to the electrically conducting PPY they display enhanced specific power absorption rates on the basis of per unit weight of Fe as compared to the seed Fe3O4 particles. The surfaces of these nanoparticles can be further functionalized with cell-targeting molecules such as folic acid. The potential of using folic acid-functionalized PPY-Fe3O4 nanoparticles in cancer cell targeting was investigated and it was observed that the uptake of these nanoparticles by MCF-7 breast cancer cells is significantly enhanced as compared to non-functionalized ones. Such nanoparticles with cancer cell targeting capability and enhanced specific power absorption rates hold great promise for use in the intracellular hyperthermia treatment of cancer tumors.