Magneto-conducting multifunctional Janus microbots for intracellular delivery of biomolecules

Although several advances have been made in the field of medicine during the last few decades, yet targeted delivery of biomolecules is still a significant challenge. Thus, the present study illustrates the fabrication of dual nature magneto-conducting Fe₃ O₄ -SU8 derived carbon-based Janus microbots that could deliver biomolecules efficiently inside cells. These microsystems possess dual properties, that is, the half part is magneto-conducting, and another half is only conducting for sufficing the therapeutic payloads efficiently under electromagnetic stimulations. These microbots are intrinsically fluorescent, which can help to trace them intracellularly without using any dye. UV photolithography was employed to design these low aspect ratio microbots (feature size ∼2.5 μm diameter and 3.7 μm length) for attaining better control over locomotion with minimum magnetic field intensity. Interestingly, Janus microbots achieved a higher speed in the electric field (44 µm/s) as compared to the magnetic field (18 µm/s). Moreover, in vitro studies show a higher microbots uptake by HeLa cells in the presence of an external electric field as compared to without electrical field stimulation.