Nov 17 2004
Virginia Commonwealth University engineers and scientists have developed and patented a unique technique to grow three-dimensional tissues and organs in a mold made from material the human body naturally uses to repair wounds, potentially eliminating the chance for rejection.
If successful, the new technique eventually would allow patients to grow new organs from their own cells and in effect, be their own transplant donors, said Gary Bowlin, Ph.D., an associate professor of biomedical engineering and co-inventor of the technique.
The U.S. Patent and Trademark Office has issued VCU a patent for Plasma-Derived Fibrin-Based Matrices and Tissues, a process that offers an alternative approach in tissue engineering — creating a three-dimensional matrix using a patient’s plasma as a source of fibrin, the scaffold the body uses in wound healing.
“In the future, our goal is to use the fibrin-based matrices and tissue to regenerate tissues and organs clinically,” Bowlin said. “Using fibrin directly from the human body to create a three-dimensional matrix for tissue regeneration was the key to our research, and this work could lead to the development of products that will improve the quality of life for many patients.”
According to the VCU team, using the scaffold and cells from the patient reduces the risk for host rejection of the new tissue or organ. Also, because the cells are taken from the patient, there is no exposure to viruses that are not already present in the patient. However, there are limitations to this approach due to cell availability and reproduction.
Eventually, engineers and scientists would be able, for example, to take a patient with a cirrhotic liver, extract some healthy liver cells and then grow the liver cells as a micro-organ in a fibrin matrix. The new organ then could be placed back into the patient.
Previously, researchers worked with collagen gels to form similar matrices with the hope that the collagen and cells would interact appropriately to form a healthy matrix and regenerate the tissue and organs. Little success was observed with the collagen gel because, as opposed to wound-repairing, regenerative properties of fibrin, it was considered a “normal” environment.
“The fibrin-based matrices and tissue has the potential to work because we are using the body’s provisional matrix that promotes normal regeneration in the body,” Bowlin said. “The cells will enter the fibrin-based matrix and should automatically recognize that they have entered a ‘wound’ and understand that their job is to now regenerate.”
Fibrinogen, a blood coagulation protein in the body, helps the body to form clots. It also promotes cell adhesion and wound healing. When a person is injured or cut, fibrinogen is broken down by an enzyme to form short fibers known as fibrin, which grows into a meshwork or netting. Fibrin holds the clot together, and it eventually becomes stabilized. Fibrin meshwork acts as a provisional matrix that guides the regeneration of wounds.
The next step in research is laboratory studies to observe the interaction of different types of cells from different parts of the body with the fibrin-based matrices and tissue.
The patent is the first step in a long process that includes pre-clinical and clinical trials and could take up to 15 years, Bowlin said.
Working with Bowlin were: Marcus Carr, Ph.D., professor of internal medicine and biomedical engineering; David Simpson, Ph.D., associate professor of anatomy and neurobiology; Gary Wnek, Ph.D., former professor of chemical engineering at VCU, now at Case Western Reserve University; Helen Fillmore, Ph.D., assistant professor of neurosurgery; and Philippe Lam, Ph.D., former research assistant professor of chemical engineering at VCU.