Bio-Conductive Polymers for Treating Myocardial Conductive Defects: Long-Term Efficacy Study

Area of Science:

• Biomaterials Science
• Cardiovascular Research
• Regenerative Medicine

Background:

• Myocardial infarction (MI) results in nonconductive fibrotic scars, causing ventricular dysfunction and arrhythmias.
• Electrical uncoupling between healthy and scarred myocardium leads to sudden cardiac death and heart failure.

Purpose of the Study:

• To evaluate the safety, durability, and efficacy of poly-3-amino-4-methoxybenzoic acid-gelatin (PAMB-G) as a conductive biomaterial for cardiac repair.

Main Methods:

• Intravenous and intramyocardial injections of PAMB-G in mice and myocardial infarction (MI) rat models.
• Toxicity assessments (acute, short-term, long-term), including body weight, organ-brain ratio, hematology, and histology.
• Functional assessments of cardiac electrical conduction, arrhythmia susceptibility, and cardiac function up to 12 months post-injection.
• Durability assessment using mass spectrometry.

Main Results:

• PAMB-G showed no acute toxicity in mice up to 1.6 mL kg⁻¹, including the therapeutic dose of 0.4 mL kg⁻¹.
• No short- or long-term toxicity was observed in MI rats for up to 12 months post-myocardial injection.
• PAMB-G restored electrical conduction, reduced arrhythmia susceptibility, and improved cardiac function in infarcted rat hearts.
• The biopolymer remained detectable for up to 12 months, indicating durability.
• No adverse effects on reproductive organ function or offspring were noted in rats.

Conclusions:

• PAMB-G is a safe, durable, and conductive biomaterial with therapeutic potential for post-myocardial infarction cardiac repair.
• PAMB-G effectively improves cardiac electrical properties and function, offering a promising solution for ventricular dysfunction and arrhythmia.
• The long-term safety and efficacy demonstrated by PAMB-G support its potential clinical translation for treating heart damage.