A paper published this week in APL Bioengineering discusses how researchers were able to fabricate biohybrid robots by combining a genetically engineered E. coli MG1655 substrain along with nanoerythrosomes that can swim through the body to deliver drugs and other therapies right to the place that needs it. These robots are made of materials like bacteria that doesn’t trigger the body’s immune response so that they can swim to the affected area, penetrate cells, and deliver their “cargo.
Nanoerythrosomes are drug carriers that are vesicles prepared by extruding red blood cell ghosts. Essentially, red blood cells are emptied, and the remaining cell membrane gets filtered down to nanoscale size. These red blood cell carriers then attach to the bacterial membrane.
The E. coli MG 1655 substrain does the mechanical work by propelling itself through the body. Researchers tracked the bacteria using a custom 2D object tracking algorithm. The biohybrid microswimmers with bacteria carrying nanoerythrosomes were 40% faster than other E. coli based microswimmers.
Due to their speed, the biohybrid microswimmers can deliver drugs faster with less immune response. The researchers will continue to fine-tune the ability of the biohybrid robots to clear the immune system as well as investigate their application to tumors.
"This work is an important stepping stone in our overarching goal of developing and deploying biohybrid microrobots for therapeutic cargo delivery," author Metin Sitti said. "If you decrease the size of red blood cells to nanoscale and functionalize the body of the bacteria, you could obtain additional superior properties that will be crucial in the translation of the medical micro-robotics to clinics."