A new research from the University at Buffalo Department of Chemical and Biological Engineering announced that tissue engineered blood vessels that have been constructed from the bone marrow adult stem cells may serve as a patient’s own source of new blood vessels in the future. This is achieved through a coronary bypass or other procedures for vessel replacement.
For an experiment like this, a microscope for phase contrast may be used. Living cells which are usually in culture and thin tissue specimens are best viewed under a microscope for phase contrast. Because living cells can be examined at their natural state, ongoing biological processes can be observed under this microscope for phase contrast. As such, this microscope for phase contrast is a beneficial tool in tissue engineering studies. With such microscope for phase contrast, living tissues can be scrutinized better.
Going back to the article, Stelios T. Andreadis, Ph.D., an associate professor in the UB Department of Chemical and Biological Engineering in the School of Engineering and Applied Sciences, said that the results of their study proved that marrow is an excellent source of adult stem cells because such cells contain smooth muscle and endothelial cells. As such, these stem cells can be applied in cardiovascular regenerative medicine.
The research revealed the potential for eventually culturing tissue engineered blood vessels from stem cells taken from the patients who need them. Currently, venous grafts routinely performed in patients undergoing coronary bypass operations. Now, with these findings on tissue engineered blood vessels, a desirable alternative to may be provided since venous grafts have the disadvantages of limited blood vessel availability, pain and discomfort at the donor site, and a high failure rate of ten years.
The UB researchers have created an innovative way of isolating the functional smooth muscle cells from bone marrow. In order to achieve such, they used a fluorescent marker protein and a tissue-specific promoter for alpha-actin, which is a protein found in muscles. This protein is responsible the contraction and relaxation of blood vessels. However, the tissue engineered vessels are not yet strong enough for coronary applications.
As the research progressed, the said blood vessels were able to similarly perform to native tissue in critical ways. The blood vessels had the same morphology and contained several smooth muscle cell proteins. Also, the tissue engineered vessels had the ability to proliferate and contract in response to vasoconstrictors, which is one of the most blood vessel important properties. Furthermore, the tissue cultured vessels also produced collagen and elastin, which are responsible for the strength and elasticity of connective tissues and are essential to the performance of artificial blood vessels.
Andreadis also remarked that these tissue cultured blood vessels are the first tissue engineered vessels that were able to produce elastin in vivo. Furthermore, the smooth muscle cells isolated from the bone marrow can differentiate into several cell types or known as mesenchymal cells. Mesenchymal stem cells do not activate an immune reaction when transplanted into another individual. Thus, they are immunoprivileged. As such, with the tissue engineered vessels, developing a universal cell source for smooth muscle cells may be possible.
The tissue cultured cells were implanted to test sheep and they displayed normal functions for five week. The UB group is currently working on how to make such engineered vessels stronger.More on this topic