The conductive function of biopolymer corrects myocardial scar conduction blockage and resynchronizes contraction to prevent heart failure.

Biomaterials

Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada; Division of Cardiovascular Surgery, Department of Surgery, University Health Network and University of Toronto, Toronto, Canada. Electronic address:

Published: November 2020

Myocardial fibrosis, resulting from ischemic injury, increases tissue resistivity in the infarct area, which impedes heart synchronous electrical propagation. The uneven conduction between myocardium and fibrotic tissue leads to dys-synchronous contraction, which progresses towards ventricular dysfunction. We synthesized a conductive poly-pyrrole-chitosan hydrogel (PPY-CHI), and investigated its capabilities in improving electrical propagation in fibrotic tissue, as well as resynchronizing cardiac contraction to preserve cardiac function. In an in vitro fibrotic scar model, conductivity increased in proportion to the amount of PPY-CHI hydrogel added. To elucidate the mechanism of interaction between myocardial ionic changes and electrical current, an equivalent circuit model was used, which showed that PPY-CHI resistance was 10 times lower, and latency time 5 times shorter, compared to controls. Using a rat myocardial infarction (MI) model, PPY-CHI was injected into fibrotic tissue 7 days post MI. There, PPY-CHI reduced tissue resistance by 30%, improved electrical conduction across the fibrotic scar by 33%, enhanced field potential amplitudes by 2 times, and resynchronized cardiac contraction. PPY-CHI hydrogel also preserved cardiac function at 3 months, and reduced susceptibility to arrhythmia by 30% post-MI. These data demonstrated that the conductive PPY-CHI hydrogel reduced fibrotic scar resistivity, and enhanced electrical conduction, to synchronize cardiac contraction.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.biomaterials.2020.120285DOI Listing

Publication Analysis

Top Keywords

fibrotic tissue
12
cardiac contraction
12
fibrotic scar
12
ppy-chi hydrogel
12
electrical propagation
8
cardiac function
8
model ppy-chi
8
electrical conduction
8
ppy-chi
7
fibrotic
6

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!