Microbial-based magnetic nanoparticles production: a mini-review.

The ever-increasing biomedical application of magnetic nanoparticles (MNPs) implies increasing demand in their scalable and high-throughput production, with finely tuned and well-controlled characteristics. One of the options to meet the demand is microbial production by nanoparticles-synthesizing bacteria. This approach has several benefits over the standard chemical synthesis methods, including improved homogeneity of synthesis, cost-effectiveness, safety and eco-friendliness. There are, however, specific challenges emanating from the nature of the approach that are to be accounted and resolved in each manufacturing instance. Most of the challenges can be resolved by proper selection of the producing organism and optimizing cell culture and nanoparticles extraction conditions. Other issues require development of proper continuous production equipment, medium usage optimization and precursor ions recycling. This mini-review focuses on the related topics in microbial synthesis of MNPs: producing organisms, culturing methods, nanoparticles characteristics tuning, nanoparticles yield and synthesis timeframe considerations, nanoparticles isolation as well as on the respective challenges and possible solutions.

Physicochemical Properties of Magnetic Nanoparticles: Implications for Biomedical Applications In Vitro and In Vivo.

Magnetic and superparamagnetic iron oxide nanoparticles are emerging as promising candidates for various applications in biology and medicine, and especially in oncology. These applications, however, require that a specific set of physical, chemical, and biological properties be combined in a given sample of nanoparticles for them to act as intended. Some of these properties are fundamental: They strictly determine the nanoparticles' behavior both in vitro and in vivo. These properties are the charge, the solution stability and zeta potential, and the coating of the nanoparticles. A certain combination of these properties may satisfy a researcher in an in vitro study, but other properties should also be considered when in vivo applications are planned. For in vivo experiments, additional determinants of the quality of nanoparticles are their size, shape, modifications with targeting moieties, and degradation/excretion pathways. All these properties are in the focus of the present review.