An injectable hydrogen-producing bacteria hydrogel for cardiac repair in rodent and porcine models

Abstract

Cardioprotective effects of current therapies for mitigating ischaemia/reperfusion (I/R) injury have had limited success. The major challenge is to effectively control oxidative stress while preserving mitochondrial function in a timely manner. Hydrogen (H2) selectively reduces cytotoxic oxygen radicals, aiding in the regulation of physiological and pathological functions. However, the efficacy of H2 therapy is highly dependent on the amount and rate of H2 release, making it critically important to develop rapid, simple and efficient techniques for evolving therapeutic H2. Here we encapsulate H2-producing photosynthetic bacteria (PSB) in an injectable porcine dermal extracellular matrix (ECM) hydrogel to facilitate cardiac I/R injury repair. Upon light exposure, sustained and high H2 production from PSB hydrogel preserves mitochondrial homeostasis and essential functions. In a porcine model of cardiac I/R injury, PSB hydrogel treatment effectively mitigates myocardial damage and salvages jeopardized myocardium. We anticipate that this bacterial therapy for photosynthetic H2 production could provide an improved treatment for I/R-related diseases.