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.