The congress, which is being presented by the Pittsburgh Tissue Engineering Initiative (PTEI), began today and concludes April 27 with joint sessions with the Society for Biomaterials Annual Meeting. Both meetings are at the Westin Convention Center Hotel, downtown Pittsburgh.
Serving as chairman of the Regenerate World Congress is Alan J. Russell, Ph.D., director of the McGowan Institute and professor of surgery at the University of Pittsburgh School of Medicine, PTEI executive director and TERMIS president. William Wagner, Ph.D., McGowan Institute deputy director, and an associate professor of surgery, chemical engineering and bioengineering, is scientific chairman.
The Regenerate World Congress provides a forum for the latest research on tissue engineering/regenerative medicine approaches to restoring the function of damaged or diseased tissues and organs. It will be held every three years, with the next congress in Korea in 2009.
Among the presentations being presented by McGowan Institute-affiliated researchers are studies focused on the development of a biohybrid lung device, the regenerative potential of stem cells from placenta, muscle or fat tissue; biomechanical training of tissue constructs; and creation of an artificial esophagus using an extracellular matrix scaffold. Following are highlights of just some of this research:
Blood vessel workout: Progenitor cells can be mechanically induced to become cells for building new blood vessels
Using a unique "panel" of mechanical stimulations that accurately mimic the pressure, strain and shear forces that blood vessels are normally subjected to, researchers have demonstrated for the first time that bone marrow-derived progenitor cells can be stimulated to differentiate into mature cells in a dose-dependent manner.
One specific type of stimulation, called cyclic pressure, dramatically increased the differentiation of progenitor cells, according to research presented by Timothy M. Maul, a pre-doctoral fellow in the department of bioengineering who is working in the laboratory of David Vorp, Ph.D., associate professor of surgery and bioengineering, University of Pittsburgh School of Medicine. Why cyclic pressure, which mimics the hydrostatic pressure that causes the stretching of blood vessels, is able to yield greater numbers of differentiated cells is unclear. The researchers plan to look at gene expression patterns for biochemical markers and proteins known to influence the way cells behave to get a more accurate picture. "Once we are able to understand exactly what is being switched on or off by mechanical stimulation, we can potentially use appropriate types and magnitudes of forces to help guide progenitor cells into becoming mature cell types useful for engineering new blood vessel tissue," he explained.
Cardiac patch helps heal heart after attack, according to animal studies
A tissue-engineered cardiac "patch" promoted both tissue and vessel formation and improved heart function weeks after heart attack, according to researchers who tested the biodegradable material in small animal studies. Their findings suggest a new therapeutic option for preventing heart failure following myocardial infarction.
"The patch helps keep the tissue thick and mechanically softer, creating a more conducive environment for healing instead of scar tissue formation," explains William Wagner, Ph.D., associate professor of surgery, chemical engineering and bioengineering at the University of Pittsburgh, deputy director of the McGowan Institute and scientific chairman of the Regenerate World Congress. Made of a flexible, microporous polyester urethane material that biodegrades over time, the cardiac patch promoted growth of new vessels and of smooth muscle cell bundles that may aid the contractile function of the heart, the researchers found. By comparison, rats that did not have the patch applied had profound scarring and thinning of the left ventricle wall. According to Dr. Wagner, future studies will determine if seeding the patch with muscle-derived stem cells can bring about even greater improvements in healing and heart function.
Double bonus: Delivering chemotherapy in a gel may improve breast cancer treatment while also reducing breast deformity
By encapsulating a common breast cancer chemotherapy drug, doxorubicin, in microspheres, or beads, and then mixing them with a gelatin made of a polymer, researchers have found that they can successfully control the delivery of chemotherapy in animals. In addition to delivering chemotherapy in a more controlled fashion, the researchers believe the gel may help decrease the occurrences of breast deformities that often occur after surgery and radiation treatment.
Researchers at the McGowan Institute for Regenerative Medicine, in collaboration with bioengineers at Carnegie Mellon University, inserted the chemotherapy-containing gel under the skin next to the mammary gland in mice with experimental breast tumors. After 30 days, they found that the tumors were completely eradicated compared to a control group of mice. "We sought to develop a possible alternative to radiation therapy that would not only release chemotherapy slowly to kill the cancerous cells left behind after surgery but that also would fill in the dimples and sometimes quite significant indentations that are common after tumor removal by surgery or radiation," said Howard D. Edington, M.D., a faculty member at McGowan, who also is associate professor of surgery and surgical oncology at the University of Pittsburgh and chief of surgery at Magee-Womens Hospital. Following additional laboratory studies, the next step will be to conduct clinical trials on women with breast cancer, said Dr. Edington.
The McGowan Institute for Regenerative Medicine was established by the University of Pittsburgh School of Medicine and University of Pittsburgh Medical Center to realize the vast potential of tissue engineering and other techniques aimed at repairing damaged or diseased tissues and organs. It serves as a single base of operations for the university's leading scientists and clinical faculty working to develop tissue engineering, cellular therapies, biosurgery techniques and artificial and biohybrid organ devices.