An innovative approach to implants
New biomaterials could make implants safer and cheaper
Archived article from Oct 23, 1998
By Amy Vames
Chances are, you or someone you know has some form of artificial implant: a heart valve made from plastic and metal, a breast implant made from silicone, a bone pin made from stainless steel.
More than 17 million Americans carry some form of implant in their bodies. But all existing implants elicit a reaction, such as inflammation or unwanted fibrous growth. Moreover, the devices themselves eventually deteriorate, requiring reconstruction procedures that are among the costliest of therapies.
What doctors need, said Joachim Kohn, director of the New Jersey Center for Biomaterials and Medical Devices based at Rutgers, is an implant that will foster tissue regeneration and then degrade in the body once it has served its purpose. Kohn, a professor of chemistry, and Kathryn Uhrich, an assistant professor of chemistry, are working to create new polymeric implant materials that will do just that. Industry and federal funds, such as a recent $905,000 grant to Kohn from the National Institutes of Health, are providing support for the effort, which bridges the strategic-planning growth areas of engineering and the life sciences.
Kohn's work is already showing signs of success. He and his colleagues have begun creating biomaterials that, upon implantation, serve as a scaffold onto which cells attach and multiply. As the cells grow into functional tissue, the polymer degrades harmlessly, leaving only healthy tissue behind. Sophisticated methods of synthesizing the materials, developed in Kohn's laboratory, allow tailoring the scaffolds to attract specific cell types. Thus, one material would promote bone growth while another might promote blood-vessel wall growth.
Such an approach, Kohn pointed out, relies on the ability to develop large numbers of biomaterials for the many tissue types found in the body. To create this extensive library of biomaterials in a short period of time, Kohn adapted the process of combinatorial chemistry, long used in the pharma-ceutical industry to generate great numbers of potential drugs. Kohn is the first to apply concepts related to combinatorial chemistry to biomaterials. Once the polymers are synthesized, they can be fabricated into a variety of shapes for specific applications.
This innovative technique has led to a licensing agreement between the university and a new company, Advanced Materials Design. The company's president, Arikha Moses, said "biomaterials made using this method could raise the efficacy and lower the cost of many different types of implants. We think these new materials will foster the development of novel healing and tissue-reconstruction strategies in markets with unmet needs."
"Building partnerships with industry is an important mechanism for advancing the development of these biomaterials," Kohn added. Other companies that his laboratory is working with are Integra LifeSciences Corp., Veritas Medical Technologies Inc. and Convatec, a Bristol-Myers Squibb company. Uhrich's laboratory works with Advanced Renal Technology, Hoechst and Provid.
As director of the New Jersey Center for Biomaterials and Medical Devices, Kohn leads a statewide program that promotes and assists such partnerships. The center is sponsored by Rutgers, the University of Medicine and Dentistry of New Jersey, and the New Jersey Institute of Technology in coordination with Princeton University. The center receives operating support from the New Jersey Commission on Science and Technology.