Novel biomaterials for regenerating cartilage tissue
More than 30 million adults in the United States suffer from osteoarthritis (OA), a disease of the joints that affects both the bones and the cartilage that coats the ends of the bones. OA causes cartilage deterioration, which, in turn, causes swelling and pain in the joint. Cartilage has limited ability to self-repair; currently, all treatments address the symptoms and not the underlying disease.
Exercise, weight loss and medication are often recommended. Other treatments include grafts, autologous chondrocyte implantation (implanting the patient’s own cartilage-producing cells), and microfracture (creating tiny fractures in the bone to allow new cartilage to develop). Once a large area of cartilage is affected, the main option is whole joint replacement. While joint replacement works well, there are concerns that patients are outliving the length of time the replacement will work, and cartilage replacement does not treat the underlying disease.
Enter cartilage tissue engineering — the development of a temporary construct that promotes tissue regeneration through the use of a scaffold, cells, and bioactive factors. While this approach is promising, there are many challenges, such as integration with surrounding tissue, longevity, and creating the right biochemical and mechanical properties to match the surrounding tissue. Also, since inflammation degraded the original cartilage, the new cartilage is put into a highly inflammatory environment that will likely degrade the new cartilage as well. The result is that decades of research have not yielded a viable, long-term, engineered cartilage therapy.
Our lab is investigating in vitro (in a test environment) inflammation models that mimic the in vivo (in a living organism) osteoarthritic environment so we can design constructs that withstand the destructive environment of OA. We have developed a novel bio-based hydrogel, inspired by native cartilage, that promotes differentiation of stem cells and generation of cartilage tissue. The materials we are using are based on molecules found in native cartilage, and are designed to both encourage new cartilage production and resist inflammation-mediated degradation.
We are collaborating with Dr. Alyssa Panitch at the University of California, Davis to develop modified biopolymers that confer inflammation-resistant properties. We are also working with Dr. Gert J. Breur and Dr. Abigail Cox in the Purdue University College of Veterinary Medicine. Funding for our work comes from the generous donations of Purdue alumni, and we are seeking funding from the National Institutes of Health (NIH).
Cartilage tissue engineering and regenerative medicine have an important role to play in the future of medicine. Tissue engineering is moving closer to fully restoring native functions of tissue by probing the body’s innate ability to repair itself. As medicine continues to become more personalized, regenerative medicine will lead to further exciting discoveries and treatments.
Collaboration is essential for addressing these and the many other challenges in biotech applications. Chemical engineering is often thought of as a cross-disciplinary field, developing skills in mathematics, physics, biology and chemistry. Chemical engineers have the unique ability to bridge numerous disciplines to create holistic technologies. They are able to communicate at a higher level across these disciplines because of their diverse background in many fields.
Julie C. Liu
Associate Professor, Davidson School of Chemical Engineering;
Associate Professor, Weldon School of Biomedical Engineering
College of Engineering, Purdue University
Carly M. Battistoni
Graduate Research Assistant, Davidson School of Chemical Engineering,
College of Engineering, Purdue University
