Urartu Seker1
Bilkent University1
We have developed self-actuating genetic circuits for nanomaterial synthesis using a protein based scaffolding. The self-actuated living material systems can sense the environmental signal, process the signal using the sensor gene circuits, process the gene circuits and create an output which the final nanomaterial scaffolding biofilm protein.<sup>1 In </sup>the follow-up study we have focused on nanomagnet synthesizing and tumor colonizing living material systems. The high cancer incidence grows the demand for efficient cancer diagnostic tools with minimized side effects nowadays. Developments in this aspect bring magnetic nanoparticles (MNPs) for biomedical applications due to their stability, biocompatibility, and magnetism properties. In nature, magnetic nanocrystals are synthesized in certain organisms, including many bacteria, which help their spatial orientation and survival by sensing the earth's geomagnetic field. This work aims to convert <i>Escherichia coli</i> to accumulate magnetite, which can further be coupled with drug delivery modules. For that, we designed bacterial machines in a way to accumulate magnetite using genetic circuitries hiring Mms6 with iron-binding activity and essential in magnetite crystal formation. Our work 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. Alternatively, cellular machines are also engineered to display Mms6 peptide on the cell surface via an autotransporter protein<sup>2</sup> providing easy synthesis conditions that showed augmented MRI performance. Our findings are promising for endowing a probiotic bacterium, able to accumulate magnetite intracellularly or extracellularly, serving as theranostics agent for cancer diagnostics via MRI scanning, drug delivery, and hyperthermia treatment.<sup>3</sup> The study was supported TUBITAK 115M108