We use cookies to understand how you use our site and to improve your experience. This includes personalizing content and advertising. To learn more, click here. By continuing to use our site, you accept our use of cookies. Cookie Policy.

Features Partner Sites Information LinkXpress
Sign In
Advertise with Us
Feather Safety Razor

Download Mobile App




Events

ATTENTION: Due to the COVID-19 PANDEMIC, many events are being rescheduled for a later date, converted into virtual venues, or altogether cancelled. Please check with the event organizer or website prior to planning for any forthcoming event.

Bacteria-Based Biohybrid Microrobots Seek and Destroy Tumor Cells

By HospiMedica International staff writers
Posted on 01 Aug 2022
Print article
Image: Bacteria-based biohybrid microrobots on a mission to one day battle cancer (Photo courtesy of Max Planck Institute for Intelligent Systems)
Image: Bacteria-based biohybrid microrobots on a mission to one day battle cancer (Photo courtesy of Max Planck Institute for Intelligent Systems)

E. coli bacteria are fast and versatile swimmers that can navigate through material ranging from liquids to highly viscous tissues. But that is not all, they also have highly advanced sensing capabilities. Bacteria are drawn to chemical gradients such as low oxygen levels or high acidity – both prevalent near tumor tissue. Treating cancer by injecting bacteria in proximity is known as bacteria mediated tumor therapy. The microorganisms flow to where the tumor is located, grow there and in this way activate the immune system of patients. Bacteria mediated tumor therapy has been a therapeutic approach for more than a century. For the past few decades, scientists have looked for ways to increase the superpowers of this microorganism even further. They equipped bacteria with extra components to help fight the battle. However, adding artificial components is no easy task. Complex chemical reactions are at play, and the density rate of particles loaded onto the bacteria matters to avoid dilution. Now, scientists have combined robotics with biology by equipping E. coli bacteria with artificial components to construct biohybrid microrobots.

A team of scientists in the Physical Intelligence Department at the Max Planck Institute for Intelligent Systems (Stuttgart, Germany) attached several nanoliposomes to each bacterium. On their outer circle, these spherical-shaped carriers enclose a material (ICG, green particles) that melts when illuminated by near infrared light. Further towards the middle, inside the aqueous core, the liposomes encapsulate water soluble chemotherapeutic drug molecules (DOX). The second component the researchers attached to the bacterium is magnetic nanoparticles. When exposed to a magnetic field, the iron oxide particles serve as an on-top booster to this already highly motile microorganism. In this way, it is easier to control the swimming of bacteria – an improved design toward an in vivo application. Meanwhile, the rope binding the liposomes and magnetic particles to the bacterium is a very stable and hard to break streptavidin and biotin complex, which was developed a few years prior and comes in useful when constructing biohybrid microrobots.

The scientists managed to equip 86 out of 100 bacteria with both liposomes and magnetic particles. They showed how they succeeded in externally steering such a high-density solution through different courses. First, through an L-shaped narrow channel with two compartments on each end, with one tumor spheroid in each. Second, an even narrower set-up resembling tiny blood vessels. They added an extra permanent magnet on one side and showed how they precisely control the drug-loaded microrobots towards tumor spheroids. And third – going one step further – the team steered the microrobots through a viscous collagen gel (resembling tumor tissue) with three levels of stiffness and porosity, ranging from soft to medium to stiff.

The stiffer the collagen, the tighter the web of protein strings, the more difficult it becomes for the bacteria to find a way through the matrix. The team showed that once they add a magnetic field, the bacteria manage to navigate all the way to the other end of the gel as the bacteria had a higher force. Because of constant alignment, the bacteria found a way through the fibers. Once the microrobots are accumulated at the desired point (the tumor spheroid), a near infrared laser generates rays with temperatures of up to 55 degrees Celsius, triggering a melting process of the liposome and a release of the enclosed drugs. A low pH level or acidic environment also causes the nanoliposomes to break open – hence the drugs are released near a tumor automatically.

“Imagine we would inject such bacteria based microrobots into a cancer patient’s body. With a magnet, we could precisely steer the particles towards the tumor. Once enough microrobots surround the tumor, we point a laser at the tissue and by that trigger the drug release. Now, not only is the immune system triggered to wake up, but the additional drugs also help destroy the tumor,” said Birgül Akolpoglu, a Ph.D. student in the Physical Intelligence Department at MPI-IS. “This on-the-spot delivery would be minimally invasive for the patient, painless, bear minimal toxicity and the drugs would develop their effect where needed and not inside the entire body.”

“Bacteria-based biohybrid microrobots with medical functionalities could one day battle cancer more effectively. It is a new therapeutic approach not too far away from how we treat cancer today,” added Prof. Dr. Metin Sitti, who leads the Physical Intelligence Department. “The therapeutic effects of medical microrobots in seeking and destroying tumor cells could be substantial. Our work is a great example of basic research that aims to benefit our society.”

Related Links:
Max Planck Institute for Intelligent Systems 


Print article
IIR Middle East

Channels

Surgical Techniques

view channel
Image: Engineers have developed a process that enables soft robots to grow like plants (Photo courtesy of University of Minnesota)

Soft Robotic System Can Grow Like Plants to Allow Surgical Access to Hard-To-Reach Areas

Soft robotics is an emerging field where robots are made of soft, pliable materials as opposed to rigid ones. Soft growing robots can create new material and “grow” as they move. These machines could be... Read more

Patient Care

view channel
Image: The biomolecular film can be picked up with tweezers and placed onto a wound (Photo courtesy of TUM)

Biomolecular Wound Healing Film Adheres to Sensitive Tissue and Releases Active Ingredients

Conventional bandages may be very effective for treating smaller skin abrasions, but things get more difficult when it comes to soft-tissue injuries such as on the tongue or on sensitive surfaces like... Read more

Health IT

view channel
Image: Using digital data can improve health outcomes (Photo courtesy of Unsplash)

Electronic Health Records May Be Key to Improving Patient Care, Study Finds

When a patient gets transferred from a hospital to a nearby specialist or rehabilitation facility, it is often difficult for personnel at the new facility to access the patient’s electronic health records... Read more

Business

view channel
Image: Differentiated stapling technology for bariatric surgery (Photo courtesy of Standard Bariatrics)

Teleflex Completes Acquisition of Bariatric Stapling Technology Innovator

Teleflex Incorporated (Wayne, PA, USA), a leading global provider of medical technologies, has completed the previously announced acquisition of Standard Bariatrics, Inc. (Cincinnati, OH, USA), which has... Read more
Copyright © 2000-2022 Globetech Media. All rights reserved.