Enhanced Cardiac Differentiation of Human Cardiovascular Disease Patient-Specific Induced Pluripotent Stem Cells by Applying Unidirectional Electrical Pulses Using Aligned Electroactive Nanofibrous Scaffolds

In the embryonic heart, electrical impulses propagate in a unidirectional manner from the sinus venosus and appear to be involved in cardiogenesis. In this work, aligned and random polyaniline/polyetersulfone (PANI/PES) nanofibrous scaffolds doped by Camphor-10-sulfonic acid (beta) (CPSA) were fabricated via electrospinning and used to conduct electrical impulses in a unidirectional and multidirectional fashion, respectively. A bioreactor was subsequently engineered to apply electrical impulses to cells cultured on PANI/PES scaffolds. We established cardiovascular disease-specific induced pluripotent stem cells (CVD-iPSCs) from the fibroblasts of patients undergoing cardiothoracic surgeries. The CVD-iPSCs were seeded onto the scaffolds, cultured in cardiomyocyte-inducing factors, and exposed to electrical impulses for 1 h/day, over a 15-day time period in the bioreactor. The application of the unidirectional electrical stimulation to the cells significantly increased the number of cardiac Troponin T (cTnT+) cells in comparison to multidirectional electrical stimulation using random fibrous scaffolds. This was confirmed by real-time polymerase chain reaction for cardiac-related transcription factors (NKX2.5, GATA4, and NPPA) and a cardiac-specific structural gene (TNNT2). Here we report for the first time that applying electrical pulses in a unidirectional manner mimicking the unidirectional wave of electrical stimulation in the heart, could increase the derivation of cardiomyocytes from CVD-iPSCs.