Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bacteria navigate microparticle swarms to target: a biohybrid microrobot develops

26.06.2015

In the 1966 movie Fantastic Voyage, a submarine complete with crew is shrunk in size so that it can navigate through the human body, enabling the crew to perform surgery in the brain. This scenario remains in the realm of science fiction, and transporting a surgical team to a disease site will certainly remain fiction. Nevertheless, tiny submarines that could navigate through the body could be of great benefit: they could deliver drugs precisely to a target location, without causing side effects and stressing the whole organism.

If things go according to Metin Sitti, director of the Physical Intelligence Department at the Max Planck Institute for Intelligent Systems in Stuttgart, with the help of biohybrid microrobots targeting therapy for example within stagnant fluids inside the human body such as inside the eye, spinal cord fluid, brain lobes, or urinary tract could in the foreseeable future come close to reality.


Swarm of biohybrid systems, composed of flagellated bacteria attached to microparti-cles, navigate through stagnant fluids such as inside the eye, the spinal cord, the brain, or the urinary tract.

Dr. Metin Sitti

The little helpers would accurately home-in on targets in the body, releasing a significant amount on drug precisely at the wished target location, without stressing the rest of the human body with side effects that this medication could potentially generate.

That this dream based on the Fantastic Voyage could come true in the near future is strengthened by recent scientific outcomes, published in Scientific Reports (Nature) this month. Researchers from the Carnegie Mellon University in Pittsburgh, USA and the Max Planck Institute for Intelligent Systems in Stuttgart have shown recently that flagellated bacteria attached to a large number of microparticles can carry the microsystem as a swarm to the desired target.

Maintaining an appropriate environment, like optimal pH level or non-polluted surrounding is essential for the survival of most microorganisms like bacteria, and they have developed sensing and propelling behaviors to move away from “un-wished or bad” environments. Flagellated bacteria such as E. coli or S. marcescens move self-propelled towards a desired pH level, which is called pH-taxis.

Scientist now take advantage out of these “natural” properties and link bacteria (bio-component) to artificial components like microparticles, to create swarms of biohybrid microrobots with a size of 1 to 5 micron (micron = 1/1000 mm), which can be manufac-tured fast at low costs.

“The bacteria serves as the sensor and actuator, while the microparticle is loaded with a specific cargo, like a drug that is intended to be delivered to a specific target location, “ explains Dr. Metin Sitti, director at the Max Planck Institute for Intelligent Systems in Stuttgart.

Given the pH-tactic response of a specific bacterial strain and knowing that cancerous tumors have a lower pH compared to that of periphery normal tissue, the use of a microrobotic system for targeted drug delivery application by pH-taxis seems to be attractive.

Until now, it has been unclear whether a specific number of bacteria (mostly in the range of 1 to 10), all stochastically linked to the same microparticle, would move as a group in the same direction, without releasing the particle. And even if a swarm consis-ting of several thousand copies of these biohybrid systems would manage to do so. A team of international researchers have now shown this kind of “swarm movement” of biohybrid microrobots for the first time, examined in water-like fluids, which serve as model fluids for non-floating liquor like naturally present in spinal cord fluid, brain lobes, eye, and urinary tract of the human body.

Since the bacteria strains used for the biohybrid systems are not pathogenic for human and the complete biobybrid microrobot will degrade afterwards, no burden has to be expected for the body.

One restriction of this bacteria-propelled microrobots may be the limited distance they can swim. External guidance will be needed to get the device most of the way to its destination fast. One obvious strategy for guiding a robot to the right spot fast is to add magnetic micro/nanoparticles to its synthetic body and to steer it externally with mag-nets.

Magnetic steering would take the microrobots fast to the target region coarsely, and turning off the magnetic field would allow cell-based steering using pH-taxis to reach to the target region finely. When arrived at the target location, the drug cargo needs to be released, either actively or passively. The passive way could be that the drug itself responds on pH and will be released automatically at the preferred pH value. The active release could be achieved by remote heating of metallic nanocomponents and hydrogel body of the robot, which would trigger the drug release.

Further steps might be to genetically modify bacteria in terms of their preferred pH value or to improve their motility. Within the human body, lots of helpful bacteria are resident, for example various strains of bacteria in the intestinal mucosa are necessary for the physiological digestion.

“In all of these experiments, safety aspects are of main importance for us”, states Dr. Metin Sitti. “The bacteria and the artificial component of the biohybrid microrobot are carefully selected and engineered, to avoid any toxic effect or other negative immune response when injected into any living system in the future.”

Weitere Informationen:

http://pi.is.mpg.de/

Annette Stumpf | Max-Planck-Institut für Intelligente Systeme

More articles from Life Sciences:

nachricht Complementing conventional antibiotics
24.05.2018 | Goethe-Universität Frankfurt am Main

nachricht Building a brain, cell by cell: Researchers make a mini neuron network (of two)
23.05.2018 | Institute of Industrial Science, The University of Tokyo

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Molecular switch will facilitate the development of pioneering electro-optical devices

A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.

The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

When corals eat plastics

24.05.2018 | Ecology, The Environment and Conservation

Surgery involving ultrasound energy found to treat high blood pressure

24.05.2018 | Medical Engineering

First chip-scale broadband optical system that can sense molecules in the mid-IR

24.05.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>