On-site treatment
Damage to the myocardial area due to blockage of the vessel during a heart attack leads to the formation of scar tissue cells on the site of the dead. The attempt of the heart to replace the work of the affected area often ends with insufficiency of the ventricles or valves.
A group of researchers from the Massachusetts Institute of Technology and their colleagues from Harvard University, as well as from scientific institutes in Ireland (Royal College of Surgeons, Trinity College Dublin, Advanced Materials and BioEngineering Research (AMBER) Center, National University of Ireland) tried to stop the development of post-infarction heart failure Galway).
They developed the therapeutic epicardial device Therepi, which is a reservoir mounted directly on the damaged cardiac tissue, with a thin tube connecting it to a port on or under the patient's skin. The drug (small molecules, macromolecules or stem cells) can be injected directly into the epicardium either by a doctor or by the patient himself.
Currently, two drug delivery systems are common for the prevention and treatment of heart failure. In one case, they arrive systematically, and not directly to the site of damage. The amount of drugs used is limited due to the risk of toxic side effects, and often only a small amount reaches the damaged heart tissue.
The second method is to directly inject the drug into the heart muscle. Since several doses are required, several invasive operations are necessary.
Therepi provides targeted drug delivery with the possibility of administering an unlimited number of doses. This requires one surgical intervention to implant the reservoir into the scarring zone on the heart.
The tank itself is made of a gelatin-based polymer, and has a hemispherical shape with a flat bottom attached to the affected tissue. The bottom consists of a membrane, the permeability of which can be adjusted, allowing more drugs or larger molecules to penetrate directly into the heart tissue.
In addition, the reservoir provides a unique opportunity for stem cell therapy. If you lower the permeability of the membrane and keep the cells in the reservoir, the paracrine factors they produce will trigger the regeneration of damaged heart tissue.
In rat models, the authors showed that the device effectively improves cardiac function after a heart attack. They injected several doses of cells into the damaged heart for four weeks, and then assessed hemodynamic and functional changes using a pressure catheter and echocardiography.
In the group of rats with implanted Therepi, indicators of cardiac function (ejection fraction, fractional contraction) improved. Rats that received multiple doses of stem cells showed higher rates than rats that received only one injection or were not treated at all.
The possibilities of using Therepi are not limited to the treatment of heart diseases. The authors intend to use the device as a research tool, it will allow determining the optimal intervals of drug administration.
Therepi can be used to treat other organs after correcting the design and composition of the materials used to create the tank.
Article by W. Whyte et al. Sustained release of targeted cardiac therapy with a replaceable implanted epicardial reservoir is published in the journal Nature Biomedical Engineering.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru based on MIT News: A new way to mend a broken heart.