Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Johns Hopkins Team Deploys Hundreds of Tiny Untethered Surgical Tools in First Animal Biopsies

By using swarms of untethered grippers, each as small as a speck of dust, Johns Hopkins engineers and physicians say they have devised a new way to perform biopsies that could provide a more effective way to access narrow conduits in the body as well as find early signs of cancer or other diseases.

In two recent peer-reviewed journal articles, the team reported successful animal testing of the tiny tools, which require no batteries, wires or tethers as they seize internal tissue samples. The devices are called “mu-grippers,” incorporating the Greek letter that represents the term for “micro.”

Instead of relying on electric or pneumatic power, these star-shaped tools are autonomously activated by the body’s heat, which causes their tiny “fingers” to close on clusters of cells. Because the tools also contain a magnetic material, they can be retrieved through an existing body opening via a magnetic catheter.

In the April print edition of Gastroenterology, the researchers described their use of the mu-grippers to collect cells from the colon and esophagus of a pig, which was selected because its intestinal tract is similar to that of humans. Earlier this year, the team members reported in the journal Advanced Materials that they had successfully inserted the mu-grippers through the mouth and stomach of a live animal and released them in a hard-to-access place, the bile duct, from which they obtained tissue samples.

“This is the first time that anyone has used a sub-millimeter-sized device—the size of a dust particle—to conduct a biopsy in a live animal,” said David Gracias, an associate professor of chemical and biomolecular engineering whose lab team developed the microgrippers. “That’s a significant accomplishment. And because we can send the grippers in through natural orifices, it is an important advance in minimally invasive treatment and a step toward the ultimate goal of making surgical procedures noninvasive.”

Another member of the research team, physician Florin M. Selaru of the Johns Hopkins School of Medicine, said the mu-grippers could lead to an entirely new approach to conducting biopsies, which are considered the “gold standard” test for diagnosing cancer and other diseases.

The advantage of the mu-grippers, he said, is that they could collect far more samples from many more locations. He pointed out that the much larger forceps used during a typical colonoscopy may remove 30 to 40 pieces of tissue to be studied for signs of cancer. But despite a doctor’s best intentions, the small number of specimens makes it easy to miss diseased lesions.

“What’s the likelihood of finding the needle in the haystack?” said Selaru, an assistant professor in the Division of Gastroenterology and Hepatology. “Based on a small sample, you can’t always draw accurate inferences. We need to be able to do a larger statistical sampling of the tissue. That’s what would give us enough statistical power to draw a conclusion, which, in essence, is what we’re trying to do with the microgrippers. We could deploy hundreds or even thousands of these grippers to get more samples and a better idea of what kind of or whether a disease is present.”

Although each mu-gripper can grab a much smaller tissue sample than larger biopsy tools, the researchers said each gripper can retrieve enough cells for effective microscopic inspection and genetic analysis. Armed with this information, they said, the patient’s physician could be better prepared to diagnose and treat the patient.

This approach would be possible through the latest application of the Gracias lab’s self-assembling tiny surgical tools, which can be activated by heat or chemicals, without relying on electrical wires, tubes, batteries or tethers. The low-cost devices are fabricated through photolithography, the same process used to make computer chips. Their fingerlike projections are made of materials that would normally curl inward, but the team adds a polymer resin to give the joints rigidity and to keep the digits from closing.

Prior to a biopsy, the grippers are kept on ice, so that the fingers remain in this extended position. An endoscopy tool then is used to insert hundreds of grippers into the area targeted for a biopsy. Within about five minutes, the warmth of the body causes the polymer coating to soften, and the fingers curl inward to grasp some tissue. A magnetic tool is then inserted to retrieve them.

Although the animal testing results are promising, the researchers said the process will require further refinement before human testing can begin. “The next step is improving how we deploy the grippers,” Selaru said. “The concept is sound, but we still need to address some of the details. The other thing we need to do is thorough safety studies.”

Further development can be costly, however. The team has applied for grants to fund advances in the project, which is protected by provisional patents obtained through the Johns Hopkins Technology Transfer Office. Biotechnology investors might also help move the project forward. “It is more a question of money than time as to how long it will take before we could use this in human patients,” Selaru said

Along with Gracias and Selaru, the Johns Hopkins researchers who contributed significantly to the two journal articles were Evin Gultepe, Sumitaka Yamanaka, Eun Shin and Anthony Kalloo. Additional contributors were Kate E. Laflin, Sachin Kadam, Yoosun Shim, Alexandru V. Olaru, Berkeley Limketkai, Mouen A. Khashab and Jatinder S. Randhawa. The researchers are affiliated with the School of Medicine, the Whiting School of Engineering and the Johns Hopkins Institute for NanoBioTechnology.

Funding for this research has come from the National Institutes of Health, the National Science Foundation, the Flight Attendants Medical Research Institute and the Broad Medical Research Institute.

The Advanced Materials journal article can be viewed here:
Biopsy with thermally-responsive untethered microtools, E. Gultepe, J. S. Randhawa, S. Kadam, S. Yamanaka, F. M. Selaru, E. J. Shin, A. N. Kalloo, D. H. Gracias, Advanced Materials 25, 4, 514-519 (2013) (Video Link: Deployment of the mu-grippers) (Video Link: Retrieval of the mu-grippers)

The Gastroenterology journal article and accompanying video can be viewed here:
Biologic tissue sampling with untethered microgrippers, E. Gultepe, S. Yamanaka, K. E. Laflin, S. Kadam, Y.S. Shim, A. V. Olaru, B. Limketkai, M. A. Khashab, A. N. Kalloo, D. H. Gracias, F. M. Selaru, Gastroenterology 144, 4, 691-693 (2013).

Phil Sneiderman | EurekAlert!
Further information:

More articles from Medical Engineering:

nachricht Gentle sensors for diagnosing brain disorders
29.09.2016 | King Abdullah University of Science and Technology

nachricht New imaging technique in Alzheimer’s disease - opens up possibilities for new drug development
28.09.2016 | Lund University

All articles from Medical Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>