In Vitro Simulation of Native Biological Condition of Cardiomyocytes

Background: Cardiac tissue engineering is one of the most promising procedures for heart regeneration and its main goal is to mimic the body s natural tissue with the significant role of scaffolds and mechanical simulation. Using an eslectrospun aligned nanofiber scaffold similar to the cardiac Extracellular Matrix (ECM) and applying a mechanical loading in the direc-tion of aligned nanofibers, the expression of contraction-related genes in Cardiac Progenitor Cells (CPCs) which have been seeded on the scaffold, would be increased.Materials and Methods: In this study, an aligned Polycaprol-actone (PCL) / Gelatin nanofiber scaffold was produced with a ratio of 70 to 30 respectively. The hydrophilicity and strength of the scaffold were examined with the contact angle test and mechanical strength analysis. The homogenization of the na-nofibers and cell viability also have been analyzed with scan-ning electron microscopy (SEM) images and MTS assay. Then to specify the effect of contraction simulation, a developed Mechanical Loading Device (MLD) applied mechanical stress with the frequency of 1Hz and 10% strain rate in direction of the aligned nanofibers in order to provide a dynamic platform for seeded CPCs. After 5 days, the quantitative reverse tran-scriptase PCR (qRT-PCR) analysis evaluated the expression of the genes responsible for synchronizing beating cells (MYH-6, TTN, and CX-43) in the dynamic scaffold compared to the con-trol sample with static culture system.Results: Our results from the chemical and physical charac-teristics of the scaffold, showed us that the scaffold with the contact angle of 46.96 and ultimate tensile strength at 17% ten-sion could be undergone the mechanical loading. The qRT-PCR analysis demonstrated that contraction related genes had been expressed higher in dynamic sample indicating an appropriate transfer of tension force through CPCs.Conclusion: Based on this study, by simulating the native car-diomyocytes condition in-vitro, the genes that are responsible for synchronized cardiac contraction have been expressed in the higher level in the analyzed CPCs. So, these cells would be a suitable candidate for transplantation to the damaged heart tis-sue without the possibility of developing the arrhythmia.