The cellular magnetic response and biocompatibility of biogenic zinc- and cobalt-doped magnetite nanoparticles

Abstract

The magnetic moment and anisotropy of magnetite nanoparticles can be optimised by doping with transition metal cations, enabling their properties to be tuned for different biomedical applications. In this study, we assessed the suitability of bacterially synthesized zinc- and cobalt-doped magnetite nanoparticles for biomedical applications. To do this we measured cellular viability and activity in primary human bone marrow-derived mesenchymal stem cells and human osteosarcoma-derived cells. Using AC susceptibility we studied doping induced changes in the magnetic response of the nanoparticles both as stable aqueous suspensions and when associated with cells. Our findings show that the magnetic response of the particles was altered after cellular interaction with a reduction in their mobility. In particular, the strongest AC susceptibility signal measured in vitro was from cells containing high-moment zinc-doped particles, whilst no signal was observed in cells containing the high-anisotropy cobalt-doped particles. For both particle types we found that the moderate dopant levels required for optimum magnetic properties did not alter their cytotoxicity or affect osteogenic differentiation of the stem cells. Thus, despite the known cytotoxicity of cobalt and zinc ions, these results suggest that iron oxide nanoparticles can be doped to sufficiently tailor their magnetic properties without compromising cellular biocompatibility.

Remote regulation of magnetic particle targeted Wnt signaling for bone tissue engineering

“…Our experiments show that UM206 peptide alone or MNP bound UM206 with or without magnetic field stimulation has no obvious cytotoxic effects on hMSC at a range of doses. This finding agrees with previous studies which have shown the biocompatibility of iron-oxide based MNP in numerous cell types [30], [31], [32], [33], [34].…”

Cell-Promoted Nanoparticle Aggregation Decreases Nanoparticle-Induced Hyperthermia under an Alternating Magnetic Field Independently of Nanoparticle Coating, Core Size, and Subcellular Localization

“…Our results suggest that MNPs heating capacity was reduced when associated to cells compared to their performance in water, indicating that the contact of MNPs with cells may affect their heating capacity, probably due to nanoparticle aggregation. According to our results, MNP aggregation seems to be independent of the cell type, incubation time or nanoparticle coating, supporting the idea that contact with cells is sufficient to induce nanoparticle aggregation, as previously proposed [39][40][41][42][43][44] . MNP aggregation in a non-controlled way could be one of the causes of the different magnetic behavior observed in cell-induced aggregation, and could explain the inefficient response to de AMF and reduced heating capacity.…”

Alternating current (AC) susceptibility as a particle-focused probe of coating and clustering behaviour in magnetic nanoparticle suspensions

“…Thus, ACS measurements as a function of field frequency enable determination of the Brownian relaxation time and subsequently the hydrodynamic size of the particles using equation (2) above. Using this versatile characterization method, the formation of protein corona around MNPs caused by their surface charge 18,19 , the aggregation of MNPs within polymer nanocomposites 20 , and the mobility of MNPs in cells 19,21,22 , have been explored previously. Figure 1: Schematic showing the AC susceptibility versus frequency curve expected for blocked magnetic nanoparticles displaying Brownian relaxation.…”