Investigation of waste paper-derived carbon aerogel/elastomer system as a cardiac patch

Cardiovascular diseases (CVDs) are blamed for the major number of deaths around the world. Among of these is Myocardial Infarction (MI) which occurs when the flow of the blood through one of the coronary arteries is blocked, depriving the cardiomyocytes in the myocardial area under the occlusion from the nutrients and oxygen. If the perfusion does not be restored rapidly, the cardiomyocytes are exposed to chronic damages resulting in a significant cardiomyocyte loss within the myocardium. Since cardiomyocytes lack a self-replication mechanism, they cannot regenerate after such an injury. Therefore, the survivals from the acute MI end up with Heart Failure; where the left ventricle expands and the left ventricle wall becomes thinner. Ultimately, the heart becomes unable to pump a sufficient amount of blood to the different parts of the body, leading finally to the death of the patient. The current therapeutic strategies of heart failure following MI are confined to slowing the progression of the end-state condition. Myocardial Tissue Engineering (MTE) is a newly emerging field in which a combination of healthy cardiac cells and engineered cardiac patch is expected to be an excellent therapeutic strategy to regenerate the infarcted myocardium. However, finding the optimal culture substrate to be a successful cardiac patch is still an open question. Therefore, this study aimed at synthesizing novel conductive elastomer-based composite and evaluate its potential as a cardiac patch for myocardial tissue engineering. In particular, we describe, for the first time, the synthesis of an electrically conductive composite of Carbon Aerogel-embedded poly (glycerol sebacate) (CA-PGS) system. In this work, electrically conductive Carbon Aerogel, which is a waste-derived and cost-effective carbon source that its utilization in cardiac tissue engineering applications has not been explored to date, was combined to the biodegradable PGS matrix to obtain a cardiac construct with optimal properties. The resulting composite was characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) Spectroscopy, X-ray Diffraction (XRD), and Contact Angle Measurements. Furthermore, the mechanical and electrical properties of the developed system as well as the cell-material interactions were also assessed to evaluate the potential of using this novel elastomeric composite as a cardiac patch for myocardial tissue engineering. The results showed that incorporating Carbon Aerogel Microbelts (CAMs) to the polymeric matrix notably enhanced the elastic modulus and the deformability of the developed constructs, making the resulting construct matching the native cardiac tissue in terms of mechanical properties. Moreover, the addition of CAMs made the developed construct electrically conductive with a conductivity value falling within the range of that reported for the human myocardium. In the cell-matrix interaction context, the results of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium Bromide) assay demonstrated that CA-PGS composite showed no cytotoxic effects for the L929 mouse fibroblast cells in vitro. In addition, it was shown that H9C2 rat cardiac myoblast cells attached and proliferated on the composite, which gave further confirmation of composite biocompatibility and its suitability for MTE application. Taking together, it is concluded that our developed system is a promising candidate for myocardial tissue engineering for cardiac repair.