Engineered tissue is more viable with blood of its own

By adding small blood vessels to artificially grown muscle tissue, the chances of succesful tissue 'repair' rise. Without nourishing blood, thicker tissue has limited viability.

By adding the vessels, a vascular network forms, connecting itself to the vascular system of the body after implanting. In this way, the engineered tissue is better prepared. Together with scientists of MIT in Massachusetts, Clemens van Blitterswijk and Jeroen Rouwkema of the University of Twente, publish these promising results in the July issue of Nature Biotechnology.

Until now, tissue engineering -technology to repair damaged human tissue by implanting grown tissue- is still limited to thin tissue like skin. Thin skin is able to recruit blood vessels from underlying layers. When it comes to thicker tissue, blood can’t reach the cells in time: this may take days. In muscle tissue, for example, the distances between the cells and the nearest blood vessels may exceed the critical 100 to 200 microns. Without blood of their own, the cells will die.

The research team now managed to add small blood vessels, endothelial cells derived from stem cells, to the engineered tissue. This is forming a vascular network of its own, thus better preparing the new tissue. Thanks to this ‘prevascularization’ process, the tissue can connect to the body tissue easier. The scientists proved that the vascular systems connect well, by introducing vascularized human tissue into a mouse.

Prof.dr. Clemens van Blitterswijk of the BMTI Institute for Biomedical Technology in Twente is very enthusiastic: "The chances of practical application of tissue engineering rise enormously: except muscle tissue we can think of tissue that is even more complex."