Regarding the study, Asst. Prof. Şeker said, “We built engineered bacteria which can colonize at the tumor site, produce magnetic nanoparticles using a series of genetic circuits for MRI. We employed magnetite synthesizing protein from magnetotactic bacteria, a peroxidase from Rhodospirillum, and an iron transporter of E. coli Nissle 1917. In our design, engineered bacteria can transport iron from the environment, which is later oxidized from Fe2 to Fe3, and finally, magnetic nanoparticles formed by Mms6 protein. Finally, we showed MR imaging of the engineered bacteria accumulating intracellular nanomagnets. In this approach, we aim to increase the targeting, early detection of the tumors and other pathologies with high contrast MRI.”.
Today, with the high incidence of cancer, the need for high-efficiency cancer diagnostic tools has increased. Therefore, magnetic nanoparticles (MNPs) for biomedical applications play an important role in this regard due to their stability, biocompatibility, and magnetic properties. Certain organisms, including many bacteria, can sense the earth’s geomagnetic field and synthesize magnetic nanocrystals that aid their spatial orientation and survival. The work of Asst. Prof. Şeker and his research team aim to convert Escherichia coli to accumulate magnetite, which can further be coupled with drug delivery modules. The research team designed magnetite accumulating bacterial machines using genetic circuitries hiring Mms6 with iron-binding activity and essential in magnetite crystal formation. The study demonstrates that the combinatorial effect of Mms6 with ferroxidase, iron transporter protein, and material binding peptide enhances the paramagnetic behavior of the cells in magnetic resonance imaging (MRI) measurements. The cellular machines have also been designed to display the Mms6 peptide on the cell surface via an autotransporter protein with enhanced MRI performance. The findings are promising for endowing a probiotic bacterium, able to accumulate magnetite intracellularly or extracellularly, serving as a theranostics agent for cancer diagnostics via MRI scanning and hyperthermia treatment.
https://onlinelibrary.wiley.com/doi/full/10.1002/smll.202200537
