During a heart attack of a person, a part of his heart muscle loses its blood supply and cells in that part of the heart die. It damages the muscle and reduces the ability of the heart to pump blood around the body. Damage to heart muscle is irreversible. Repairing or replacing the damaged heart using nanotechnology based scaffold has a great potential.
Stem cells
Stem cells serve as the foundation upon which a future form of "cellular therapy" is constructed. The time between the injury to the heart and the application of stem cells affects the degree to which regeneration takes place, and this has real implications for the patient who is rushed unprepared to the emergency room in the wake of a heart attack. In such a case, patient's cells be harvested in advance, to minimise the preparation necessary for the cells' administration and can be tuned to genetically "programme" to migrate directly to the site of injury and to synthesize immediately the heart proteins necessary for the regeneration process.
Investigators are currently using stem cells from all sources to address these questions, thus providing a promising future for therapies for repairing or replacing the damaged heart.
Nanotechnology based stem cell therapy
Stem cell therapy can repair heart muscle cells and restore the viability and function of the area already damaged and could have a tremendous impact on modern medicine. There is no clinical therapy available for the repair of damaged heart muscle, there exist tremendous opportunities for the creation of novel nanotechnology based therapies.
Principle of scaffold
Researchers at the University of Washington have built a scaffold that supports the growth and integration of stem cell-derived cardiac muscle cells. The scaffold supports the growth of cardiac cells in the lab and encourages blood vessel growth in living animals.
Researchers built a tiny tubular porous scaffold to support and stabilize the fragile cardiac cells to be injected into a damaged heart, where it will foster cell growth and eventually dissolve away. The new scaffold not only supports cardiac muscle growth, but potentially accelerates the body's ability to supply oxygen and nutrients to the transplanted tissue.
Thus the researchers can seed the scaffold with stem cells from either the patient or a donor, and then implant it when the patient is treated for a heart attack, before scar tissue has formed. Preparing such a scaffold would be significantly cheaper and easier to use. The scaffold is a flexible polymer with interconnected pores all of the same size containing channels to accommodate cardiac cells' preference for fusing together in long chains. Over five days, the cardiac muscle cells multiplied faster in the scaffold environment than other cell types, and could survive up to 300 micrometers from the scaffold edge to integrate with the body. The cells expressed two proteins associated with muscle contraction and could contract with sufficient force to deform the scaffold. Results showed that the scaffolds are bio compatible and after four weeks the heart had accepted the foreign body, and new blood vessels penetrated into the scaffold.
The scaffold is made from a jelly-like hydrogel material and a needle is used to implant the tiny scaffold rods into the heart muscle. But the scaffold can support growth of larger clumps of heart tissue. Then scaffold degradation time is adjusted so that the scaffold degrades at the same rate that cardiac cells proliferate and that blood vessels and support fibers grow in, and then implant a cell-laden scaffold into a damaged heart.