Friday 14th December 2007
Researchers at the Imperial College in London have come up with a breakthrough technology that can help repair damage caused to the heart after an attack. The breakthrough is in the form of a stem-cell patch that can be stitched or glued over the damaged area of the heart.
Myocardial infarction or heart attack as it is commonly known, results in a part of the heart muscle losing its blood supply. This causes oxygen starvation and leads to death of cells in that area which ultimately results in scarring.
If not treated on time and in a proper manner, the scarred area can weaken and expand and eventually lead to dangerous consequences including heart failure and death. While medications can help restrict damage to the heart muscle, there is currently no treatment available to actually restore functionality to the damaged area.
Stem cells are considered to be the best bet in developing a viable treatment for this. Several groups around the world are presently working on parallel pathways to use stem cells in heart repair. The main challenge facing all of them is to get these cells to function properly.
The new development achieved by Dr. Sian Harding and colleagues answers this issue. They took beating heart cells derived from stem cells and successfully matured them in a laboratory dish for up to seven months. This gave them a biocompatible scaffold for developing the basis of a patch.
The scientists believe that if it might be possible to stitch or glue this patch of new tissues derived from embryonic stem cells over the damaged area of the heart, that area might become fully functional again.
??We really would like to cover the area of the infarct scar as much as possible, so it might be quite a large patch,? Dr. Harding said. ??We think the patch itself will stop the scar expanding, which is one of the big problems when you have a myocardial infarction because the scar becomes weak and can bulge out.?
The scientists have designed the biomaterial for the patch to have the same elasticity as heart muscle so that it fits right in. It can also be programmed to degrade safely after staying in place for at least two weeks.
The Imperial team believes their patch will be compatible with normal heart muscle because they managed to get the stem cell-derived heart cells to beat in a coordinated fashion for months on end. According to them, their patch should not lead to any abnormal heart rhythms.
In Dr. Harding??s opinion, if safety studies on animals and tests confirm that the new cells are not rejected, they should be able to start initial human trials of the patch within five years. Dr. Harding will be presenting her team??s findings at a UK Stem Cell Initiative conference to be held soon.
Stem cells have always been an ethically controversial field on account of scientists having to use human eggs or embryos to develop them. However, when researchers last month reported success with developing ordinary human skin cells into batches of cells that looked and acted like embryonic stem cells, the field received it biggest ever boost.
??That is a very promising development,? Dr. Harding said. ??They have made heart muscles from those cells and this technique has the potential both for getting round the ethical problems and for producing patient-specific cells.? She believes stem cells derived from a patient??s own tissue would ensure there would be no danger of rejection of the transplant.
