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Posted on Jun 17, 2018, 1 a.m.
Researchers have developed a device holding promise to halt progression of heart attack to heart failure with a small device that attaches directly to damaged heart tissue to deliver therapy, as published in Nature Biomedical Engineering.
After heart attack a cascade of events leading to heart failure begins, damage to the area in the heart where a blood vessel was blocked leads to scar tissue, the heart will respond to scarring by remodelling to compensate, which often ends in ventricular or valve failure.
The device called Therepi contains a reservoir that attaches to damaged heart tissue with a refill line connecting to the reservoir to a port on or under patient skin where therapies can be injected by a healthcare professional or by the patient to restore cardiac function. Heart Therepi addresses problems with current drug delivery methods by non-invasively administering localized therapies as often as needed after the reservoir is implanted on the heart in one surgical procedure.
Alternative current methods can be inefficient and involve invasive procedures that directly inject therapies in to the heart often requiring multiple surgeries, or drugs are delivered systemically rather than administered directly to the site of damage with the volume of drugs used limited to avoid toxic side effects meaning only a small amount will reach the target damaged area.
The reservoir is constructed from a gelatin based polymer in a half spherical shape with a flat bottom to attach to tissue, consisting of a semipermeable membrane which is adjustable to allow more drugs or larger materials to pass directly into heart tissue. The reservoir acts like a cell factory, rather than pass through the membrane in to the heart cells stay in the reservoir and produce paracrine factors which promote healing in the damaged tissue.
Over a four week period multiple doses of cells were administered to damaged heart tissues in rat models, hemodynamic changes in tissue were analyzed using a pressure volume catheter and echocardiography to compare functional changes over times. Therepi was shown to be effectively improve cardiac function after heart attack. Hearts which received multiple dosages of cells via Therepi had more cardiac function than those that with no treatment of only a single injection.
Therepi can go beyond treating heart disease, its capabilities can provide opportunity to treat multiple localized doses to be delivered as a tool to identify exact dosages for a variety of conditions in other parts of the body. Optimizing the design and adjusting materials could lend the Therepi reservoir to be used for a wide range of diseases and health problems in a variety of areas, the device is a platform that can be tailored to different systems and conditions providing an example of how intersectional research looking at device and biological therapies can help to create new ways to combat and treat disease.
Materials provided by Massachusetts Institute of Technology.
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Journal Reference:
William Whyte, Ellen T. Roche, Claudia E. Varela, Keegan Mendez, Shahrin Islam, Hugh O’Neill, Fiona Weafer, Reyhaneh Neghabat Shirazi, James C. Weaver, Nikolay V. Vasilyev, Peter E. McHugh, Bruce Murphy, Garry P. Duffy, Conor J. Walsh, David J. Mooney. Sustained release of targeted cardiac therapy with a replenishable implanted epicardial reservoir. Nature Biomedical Engineering, 2018; 2 (6): 416 DOI: 10.1038/s41551-018-0247-5
