Algae-Based Biohybrid Microrobots for Biomedical and Environmental Applications

Bioinspired microrobots capable of actively moving in versatile biological fluids and environmental surroundings have attracted considerable attention for biomedical and environmental applications because of their unique dynamic features that are otherwise difficult to achieve by their static counterparts. Herein, algae-based biohybrid microrobots are fabricated via click chemistry to functionalize algae with different agents from small molecules to nanoparticles (eg. angiotensin-converting enzyme 2 (ACE2) receptor and antibiotics-loaded cell membrane-coated nanoparticles). The resulting biohybrid microrobot displays fast (&gt;100 μm/s) and long-lasting self-propulsion in diverse simulated biofluid and aquatic media, obviating the need for external fuels. In a mouse model of acute pneumonia, the resulting antibiotics-loaded biohybrid algae-based microrobots achieve significant therapeutic efficacy in reducing the bacterial burden and effective treatment of bacterial infection, while showing negligible <i>in vivo</i> toxicity. In another example, the ACE2-modified algae microrobots display effective “on-the-fly” removal of SARS-CoV-2 pseudovirus in many contaminated water matrices.