Preventing the growth of cancer cells in the human body is one of the greatest challenges of modern medical science. However, a team of researchers from the Max Planck Institute for Intelligent Systems claim to have developed an advanced bacteria-mediated therapy to fight cancerous tumors. The proposed treatment involves the use of magnetically guided, bacterial-based microrobots as drug delivery agents.
Microrobots deliver drugs directly into tumors and kill cancer cells painlessly & effectively. “This point-of-care delivery would be minimally invasive, painless, with minimal toxicity for the patient, and the drugs would have an effect where it is needed and not in the whole body,” says Yunus Alapan, co-author of the study.
During their research, the researchers successfully attached nanolipomes (spherical vesicles made of lipids used to store drugs inside) and magnetic nanoparticles to about 86 E. coli bacteria. These special attachments have transformed ordinary bacteria into a small army of bacterial biohybrid micro-robots.
The science of biohybrid microrobots based on bacteria
The numerous nanoliposomes attached to each modified E. coli bacterium are actually vesicles filled with chemotherapeutic drug molecules. Its outer-covering can be easily removed upon exposure with infrared rays. On the other hand, magnetic particles (iron oxide) attached to bacteria are used to control their movement in the human body.
Because E. coli is a highly mobile microbe, the researchers exposed them to magnetic fields. The direction of the magnetic field guides the movement of the iron oxide particles and also bacteria to which they are attached. In addition, to bind the bacteria to magnetic particles & nanolipsomes, the researchers used streptavidin-biotin complexes, the strongest biomolecular binders agent that often commonly used to identify new drug targets.
Streptavidin-biotin complexes are very stable and act as unbreakable strings that bind attachments to bacteria. While further explaining the process, Birgül Akolpoglu, lead author of the study, said, “Imagine that we would inject such bacteria-based microrobots into the body of a cancer patient. With a magnet, we can precisely direct the particles towards the tumor. Once enough microrobots surround the tumor, we shine a laser into the tissue, triggering drug release. Now, not only is the immune system activated to wake up, but additional drugs also help destroy the tumor.
The researchers claim that “on the spot delivery” of chemotherapy drugs using biohybrid microrobots can be done without pain or infection inside the patient’s body. Plus, with more research and development, it could become one of the most effective cancer treatment strategies in the future.
Bacterial microrobots are the perfect match to battle cancer
Biohybrid microrobots show promise for cancer treatment based on an approach known as bacteria-mediated therapy (using bacteria to deliver drugs or release enzymes into the human body at desired sites). Surprisingly, this is not a new treatment, but it is complex. Many scientists have tried to microorganisms will anti cancer drugs.
However, most of them fail because successful treatment with this strategy requires a perfect combination of different techniques. This is where Birgül Akolpoglu and his team beat everyone. They took materials that enhance the abilities of common bacteria and turned them into highly efficient nano-machine for drug delivery.
For example, the nanoliposomes attached to the bacteria consisted of special capsules called green particles to effectively store cancer drugs. These particles only released the drug when they came into contact with infrared radiation (a laser beam). Furthermore, these particles left no-scope for interactions between therapeutic molecules and natural bacterial secretions.
To overcome problems related to motion control with E. coli, the researchers took advantage of the magnetic properties of the iron oxide particles. Therefore, by integrating robotics and physics with biology, researchers at the Max Planck Institute for Intelligent Systems have managed to come-up the perfect components needed to address the various challenges associated with bacterially mediated cancer treatment.