Kristi Anseth works at the intersection of three fields—engineering, chemistry, and biology—to design polymers that imitate living tissues, with the goal of helping the body heal itself. The polymers are meant to serve as scaffolds, or templates, on which cells can grow to replace diseased or damaged body parts, including knees, hips, cartilage, and heart valves—all without the trauma of major surgery.
Anseth is developing liquid precursors that are designed to be injected into the body and then solidified with light through a process called photopolymerization, which essentially links individual molecules together, providing the strength, stability, and flexibility to grow new cells in a three-dimensional framework. All the while, the polymers would support and guide the healing of damaged tissues before gradually dissolving as natural tissue fills in.
A chemical engineer by training, Anseth said she has always been drawn to research with medical relevance and was especially intrigued by the evolving field of tissue engineering. "This is the quintessential engineering problem," Anseth explained. "Designing polymers that can serve as cell scaffolds requires control on many size scales—from molecules to cells to functional subunits of cells to tissues and organs to the entire human body—and on many time scales—from a fraction of a second to several months."
After graduating from Purdue University with a degree in chemical engineering, Anseth went to the University of Colorado at Boulder, where she received a Ph.D. in chemical engineering in just two years. She then worked as a research fellow for two years before returning to her Colorado alma mater as an assistant professor of chemical engineering. Within a decade, she has been named an endowed chair and a distinguished professor, filed for 18 patents, and published nearly 180 research articles—quite an accomplishment for a researcher in her early 40s.
At Colorado, Anseth has already made great progress in designing and building polymers. In 2003, she and her students were the first to successfully develop an injectable and biodegradable scaffold to regenerate cartilage. These scaffolds are designed to be injected into a joint, the knee, for example, along with chondrocytes, the cells that secrete cartilage. Though it is not yet ready for clinical use, such scaffolds hold promise for treating osteoarthritis, which is caused by wear and tear on the cartilage that lines joints, as well as cartilage damaged by injuries and congenital cartilage defects.
Anseth and her students are also collaborating with other investigators to engineer human heart valves. This project is proving to be more challenging because it requires the scaffold to give instructions to the cells and provide an environment where cells can communicate with each other. But the benefit to patients would be huge. Each year in the United States, an estimated 20,000 patients die of heart-valve dysfunction, and existing surgical treatments are far from ideal. They include replacing damaged valves with mechanical valves, which require patients to take blood thinners for the rest of their lives to reduce the risk of blood clots, or heart valves from pigs, which eventually wear out.
As a faculty scientist, Anseth spends a great deal of time teaching students, both undergraduates and graduates, in the classroom and in her laboratory. Her creativity in the classroom has been recognized by several teaching awards, and working with students is part of her job that Anseth especially enjoys. "Beyond teaching the basic scientific method, I try to get my students to take risks and to explore the unexpected," Anseth explained. "This is where some of the most interesting results lie."
Dr. Anseth is also Tisone and Distinguished Professor of Chemical and Biological Engineering at the University of Colorado at Boulder and Associate Professor of Surgery in the School of Medicine at the University of Colorado Health Sciences Center, Denver.
RESEARCH ABSTRACT SUMMARY:
Kristi Anseth designs new synthetic biomaterials that can serve as extracellular matrix analogs to support three-dimensional cell culture and tissue regeneration. In particular, Anseth would like to understand how the structure, chemistry, and mechanics of these materials influence cellular functions, and ultimately tissue regeneration. Scientists who seek to regenerate organs through tissue engineering will need such "intelligent scaffolds" to guide cell organization, control cell interactions, and provide cues to cells in a temporally and spatially regulated manner.
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Photo: Brigid McAuliffe