Better targeting of stem cells as medication

Up till now it has not been possible to control stem cells in such a way that they grow into new blood vessels outside the body, or - when injected into an organ - lead to the creation of new small blood vessels and tissue repair.

Research conducted by medical biologist Guido Krenning of the University Medical Center Groningen has resulted in a method whereby the cells can be instructed. This is a great advance in curing numerous life-threatening diseases. Krenning will be awarded a PhD by the University of Groningen on 29 April 2009.

The technique of making new blood vessels in a body has been used for a long time. Several different types of stem cells can be used for this. Krenning has developed a technique whereby one type of stem cell from the blood can be transformed into several cell types that together can form a new blood vessel.

Injecting stem cells to promote organ repair is not new either. It has always been assumed that these stem cells function as 'building blocks' and thus replace the damaged tissue. Krenning has discovered that these stem cells do not act as 'building blocks' but as a 'conductor' that encourages the organ to regenerate itself. This has resulted in a better understanding of the processes behind organ repair and these can be better and more quickly applied.

Current arteriosclerosis therapies concentrate on problems with the major arteries. The aim is to restore blood flow, thus improving the functionality of the affected organs. A blood vessel from somewhere else in the body is used, or else a synthetic tube, to replace the artery where it has narrowed. The problem with using the body's own blood vessels is that they are often also affected by illness. The major drawback of a synthetic material is that it gradually silts up, resulting in new blockages. When blood vessels are created from the patient's own stem cells, these problems no longer occur.

Improving the affected organ tissue can be realised not only by improving the blood supply from the major blood vessels. A diseased organ can repair itself by making new capillaries. By injecting stem cells from the patient's blood into the affected organ, new capillaries are created. Injecting stem cells is currently being tested in clinical trials. Krenning's research has produced so much knowledge about the functioning of these stem cells in controlling tissue regeneration, that tissue repair can also be instigated by imitating the instruction that stem cells give to the damaged tissue.

The technique can now also be used in clinical situations. Cardiovascular disease is the main cause of death in the Netherlands. It is expected that the results of Krenning's research will very soon be applied in the prevention of or relief of organ diseases.