When it comes to delivering genes to living human tissue, the odds of success come down the molecule. The entire therapy – including the tools used to bring new genetic material into a cell – must have predictable effects.
Now, a new screening process will simplify non-viral transfection, providing a method researchers and clinicians to use to find an optimal set of biomaterials to deliver genes to cells.
Developed by William Murphy, the Harvey D. Spangler professor of biomedical engineering at the University of Wisconsin-Madison, the method gives researchers greater control over how cells react to the gene delivery mechanism. The broader implication is more nuanced, effective control over cell behavior. “We’ve been exploring using this concept for reprogramming of adult cells, as well as controlling differentiation of stem cell types,” he says.
Murphy and his collaborators published news of their advance in the March 28, 2013 issue of Nature Scientific Reports.
Biomedical Engineering and Orthopedics and Rehabilitation Associate Professor Bill Murphy has been named co-director of the UW-Madison Stem Cell & Regenerative Medicine Center. He joins Timothy Kamp, professor of cardiovascular medicine, at the helm.
Murphy served on the SCMRC’s first executive committee in 2007. More recently, as associate director, he led the formation of new scientific focus groups within the center. His lab team designs and synthesizes new “bioinspired” biomaterials to address a variety of regenerative medicine challenges, including stem cell differentiation, tissue regeneration, and controlled drug delivery. He is a past recipient of the National Science Foundation Career Award and the Wisconsin Vilas Associate Award.
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, 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 4 and 6, at the Orthopedic Research Society meeting in San Francisco, Darilis Suarez-Gonzalez and Jae Sung Lee of the Murphy lab reported 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.