In recent times multifunctional nanomaterials which refers to two or more heterogeneous compositions exhibiting diverse functionalities fused into one single nanostructure, has been at the center of attraction mainly due to the wide variety of potential applications. Of these, the optically active magnetic multifunctional nanomaterials (MMN) have gained special attention in the biomedical arena as active components of therapeutic and diagnostic agents. In the Nath laboratory, we have focused on creating Au-Fe3O4 MMNs through extensive hypothesis driven materials chemistry, with the motivation of using them as efficient hyperthermia agents for cancer treatment. The Au-Fe3O4 magnetic nanostructures are designed such that they can exhibit maximum efficiency towards heat generation under an applied magnetic field with lower dosing levels. These Au-Fe3O4 nanostructures were made by simple one-pot solution chemistry based method involving environmentally safe and benign precursors like Fe(CO)5 which was refluxed in presence of HAuCl4 and surfactants like oleic acid and oleylamine. By varying the reaction conditions we could make various kinds of MMN morphologies like core-shell, dumbbell and Janus-like nanoparticles. Preliminary magnetization studies with our morphology optimized Au-Fe3O4 multi-modal nanostructures suggest that they might have better hyperthermia efficiencies than the commercially produced samples, due to optimization of the superparamagnetic property. Another notable feature was that despite the bigger size of these MMNs, coupling the Fe3O4 with Au actually led to retention of the superparamagnetic properties above the critical domain through exchange bias interactions. These Au-Fe3O4 nanoparticles were functionalized with biomolecules like cysteine and (-)EGCG (epigallocatechin gallate), which can aid in internalization of these MMNs inside the disease tissue, and also help in making them readily dispersible in water which increases the probability of cell uptake. Synthesis, characterization, detailed property studies of these Au-Fe3O4 nanoparticles along with their biofunctionalization, cell viability and toxicity evaluation will be discussed in this talk.

Multifunctional magnetic nanomaterials for biomedical applications

249th National Meeting (2015)

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