An injectable conductive hydrogel encapsulating plasmid DNA-eNOs and ADSCs for treating myocardial infarction

Myocardial infarction (MI) leads to the mass death of cardiomyocytes accompanying with the unfavorable alternation of microenvironment, a fibrosis scar deprived of electrical communications, and the lack of blood supply in the infarcted myocardium. The three factors are inextricably intertwined and thus result in a conservative MI therapy efficacy in clinic. A holistic approach pertinently targeted to these three key points would be favorable to rebuild the heart functions. Here, an injectable conductive hydrogel was constructed via in situ Michael addition reaction between multi-armed conductive crosslinker tetraaniline-polyethylene glycol diacrylate (TA-PEG) and thiolated hyaluronic acid (HA-SH). The resultant soft conductive hydrogel with equivalent myocardial conductivity and anti-fatigue performance was loaded with plasmid DNA encoding eNOs (endothelial nitric oxide synthase) nanocomplexes and adipose derived stem cells (ADSCs) for treating MI. The TA-PEG/HA-SH/ADSCs/Gene hydrogel-based holistic system was injected into the infarcted myocardium of SD rats. We demonstrated an increased expression of eNOs in myocardial tissue the heightening of nitrite concentration, accompanied with upregulation of proangiogenic growth factors and myocardium related mRNA. The results of electrocardiography, cardiogram, and histological analysis convincingly revealed a distinct increase of ejection fraction (EF), shortened QRS interval, smaller infarction size, less fibrosis area, and higher vessel density, indicating a significant improvement of heart functions. This conception of combination approach by a conductive injectable hydrogel loaded with stem cells and gene-encoding eNOs nanoparticles will become a robust therapeutic strategy for the treatment of MI.