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, firstname.lastname@example.org
William Murphy | EurekAlert!
Human skin is an important source of ammonia emissions
27.05.2020 | Max-Planck-Institut für Chemie
Biotechnology: Triggered by light, a novel way to switch on an enzyme
27.05.2020 | Westfälische Wilhelms-Universität Münster
In living cells, enzymes drive biochemical metabolic processes enabling reactions to take place efficiently. It is this very ability which allows them to be used as catalysts in biotechnology, for example to create chemical products such as pharmaceutics. Researchers now identified an enzyme that, when illuminated with blue light, becomes catalytically active and initiates a reaction that was previously unknown in enzymatics. The study was published in "Nature Communications".
Enzymes: they are the central drivers for biochemical metabolic processes in every living cell, enabling reactions to take place efficiently. It is this very...
Early detection of tumors is extremely important in treating cancer. A new technique developed by researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from normal tissue. The work is published May 25 in the journal Nature Nanotechnology.
researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from...
Microelectronics as a key technology enables numerous innovations in the field of intelligent medical technology. The Fraunhofer Institute for Biomedical Engineering IBMT coordinates the BMBF cooperative project "I-call" realizing the first electronic system for ultrasound-based, safe and interference-resistant data transmission between implants in the human body.
When microelectronic systems are used for medical applications, they have to meet high requirements in terms of biocompatibility, reliability, energy...
Thomas Heine, Professor of Theoretical Chemistry at TU Dresden, together with his team, first predicted a topological 2D polymer in 2019. Only one year later, an international team led by Italian researchers was able to synthesize these materials and experimentally prove their topological properties. For the renowned journal Nature Materials, this was the occasion to invite Thomas Heine to a News and Views article, which was published this week. Under the title "Making 2D Topological Polymers a reality" Prof. Heine describes how his theory became a reality.
Ultrathin materials are extremely interesting as building blocks for next generation nano electronic devices, as it is much easier to make circuits and other...
Scientists took a leukocyte as the blueprint and developed a microrobot that has the size, shape and moving capabilities of a white blood cell. Simulating a blood vessel in a laboratory setting, they succeeded in magnetically navigating the ball-shaped microroller through this dynamic and dense environment. The drug-delivery vehicle withstood the simulated blood flow, pushing the developments in targeted drug delivery a step further: inside the body, there is no better access route to all tissues and organs than the circulatory system. A robot that could actually travel through this finely woven web would revolutionize the minimally-invasive treatment of illnesses.
A team of scientists from the Max Planck Institute for Intelligent Systems (MPI-IS) in Stuttgart invented a tiny microrobot that resembles a white blood cell...
19.05.2020 | Event News
07.04.2020 | Event News
06.04.2020 | Event News
28.05.2020 | Transportation and Logistics
28.05.2020 | Physics and Astronomy
28.05.2020 | Power and Electrical Engineering