Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Smallest tools could give biggest results in bone repair

07.02.2012
When William Murphy works with some of the most powerful tools in biology, he thinks about making tools that can fit together. These constructions sound a bit like socket wrenches, which can be assembled to turn a half-inch nut in tight quarters, or to loosen a rusted-tight one-inch bolt using a very persuasive lever.

The tools used by Murphy, an associate professor of biomedical engineering and orthopedics and rehabilitation at University of Wisconsin-Madison, however, are proteins, which are vastly more flexible than socket wrenches -- and roughly 100 million times smaller. One end of his modular tool may connect to bone, while the other end may stimulate the growth of bone, blood vessels or cartilage.

On February 4th and 6th, at the Orthopedic Research Society meeting in San Francisco, Darilis Suarez-Gonzalez and Jae Sung Lee of the Murphy lab are reporting that orthopedic implants "dip-coated" with modular growth factors can stimulate bone and blood vessel growth in sheep.

For many years, medical scientists have been fascinated by growth factors -- proteins that can stimulate tissues to grow. But these factors can be too effective or not specific enough, leading to cancer rather than the controlled growth needed for healing.

Murphy wants to start applying the manifold benefits of the modular approach to healing or regenerating bone, tendon, and ligaments, and in particular to replacement surgery after an artificial joint has loosened or failed. Temporarily stimulating bones to grow by placing growth factors near the new implant could shorten healing time and ensure a good, tight fit.

The approach could also be used for reattaching ligaments to bone after sports injuries and healing large bone defects during spinal fusion, facial reconstruction or trauma. In this work, Murphy collaborates with two associate professors of orthopedics and rehabilitation at the School of Medicine and Public Health. "Ben Graf focuses on knee injuries in sports medicine," he says, "and David Goodspeed, a lieutenant colonel in the Army who has seen blast injuries during multiple tours in Iraq, is working on the kind of major traumatic wound we think is potentially treatable using this approach."

The working end of the modular structure may feature a fragment of a growth factor, but not the entire protein. "Often, you just want the specific regions that activate the signaling pathways, because that can reduce the chances of stimulating unwanted growth, even cancer," he says.

At the other end, Murphy may place an anchoring molecule that binds to the bone and prevents the modular structure from migrating away from the wound.

With the modular approach, he says, "you might be able to stimulate bone formation without the side effects. We are trying to decrease stimulation outside of the bone defect, trying to design these molecules to specifically generate new bone in a defect, and to stay there."

Animal tests, performed in collaboration with Mark Markel, a professor of veterinary medicine, have shown that the bone is denser around the implant, and that the union between the implant and the bone is stronger than produced by state-of-the-art orthopedic techniques. The added growth factors have not been detected elsewhere in the animal, Murphy says.

Engineering each section of the molecule separately allows their properties to be tailored as needed. "We can take similar protein structures and modulate them," Murphy says. "If we want a molecule that binds very strongly to the surface of a bone graft, we can do that. If we want one that releases over controllable time-frames, we can do that as well."

Moving from the lab to the clinic is a major step, and Murphy knows that many hurdles remain. "We have shown that this can work in a large, clinically relevant animal model, but realistically, I don't see this being used in the clinic within the next five years."

Murphy says his approach is inspired by biology without trying to exactly duplicate normal communication between cells and tissues. "We are not interested in specifically mimicking a particular structure or function, but nature uses a variety of fundamental mechanisms during development and regeneration, and we are taking lessons from them and designing synthetic systems to achieve similar outcomes. We are not repeating nature, but we are inspired by nature."

David Tennenbaum, 608-265-8549, djtenenb@wisc.edu

William Murphy | EurekAlert!
Further information:
http://www.wisc.edu

More articles from Life Sciences:

nachricht Link Discovered between Immune System, Brain Structure and Memory
26.04.2017 | Universität Basel

nachricht Researchers develop eco-friendly, 4-in-1 catalyst
25.04.2017 | Brown University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Scientist invents way to trigger artificial photosynthesis to clean air

26.04.2017 | Materials Sciences

Ammonium nitrogen input increases the synthesis of anticarcinogenic compounds in broccoli

26.04.2017 | Agricultural and Forestry Science

SwRI-led team discovers lull in Mars' giant impact history

26.04.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>