In situ synthesis of biomineralized magnetic nanoparticle within hydrogel

Abstract

Magnetic nanoparticle (MNP) is of high practicle interest in the domain of biomedicine and biomedical application e.g., drug delivery, magnetic fluid hyperthermia, magnetic resonance imaging, biosensing. The magnetic nanoparticles are explored due to its high tunability of its physical and magnetic properties. A considerable effort has been devoted for the synthesis of MNP e.g., ball milling, arc melting, co-precipitation, microwave and microfluidics techniques. However, hydrogels can offer a new platform for in situ synthesis of biomineralized MNP as well as magnetic hydrogels (MH), because of its an advantageous controled network structure. It is an emerging and promising concept, as most of the biopolymer are supposed to be biodegradable that can be considered as an alternative eco-friendly material too. In this work, "PVP-CMC Hydrogel" is used as matrix for synthesis of biomineralized MNP, where the unique porous networks structure exhibited within swollen/wet PVP-CMC hydrogel. Here, PVP-CMC hydrogel function as a chemical reactor, where inorganic salts (FeCl2 and FeCl3) are reacting with precipitating agents ammonium hydro-oxide (NH4OH) to generate biomineralized MNP. This method prevents from aggregation and shows a narrow particle size distribution. X-ray diffraction studies reveal the formation of magnetite phase. Structural and morphological analysis using transmission electron microscopy shows the spherical shaped magnetic nanoparticle with size of 10 ± 2 nm. The saturation magnetization of the MNP was 78 emu/g and 12 emu/g for magnetic hydrogel. This synthesis process can be used to synthesize "bare" MNP, MH and extended to other oxides by changing the salts for the biomedical applications.