fabrication and characterization of ALG cardiac patches enriched with GO, potential for angiogenesis of HUVECs

A cardiac infarction is the leading cause of death worldwide. Although the common treatments, including medication and various grafts, are unable to return the patients to their normal life, a cardiac patch is a promising technique in the field of tissue engineering that can stimulate the natural regeneration process of the diseased tissue via a scaffold with appropriate mechanical properties, biocompatibility and electrical conductivity. In this study, the composite scaffolds based on alginate (ALG) were fabricated through freeze-drying and coated with different concentrations of graphene oxide (GO) to make ALG/xGO (x=0.01, 0.05 and 0.1 wt. %) scaffolds. The scaffolds were characterized in terms of morphology, physicochemical structure, tensile strength, electrical conductivity, and cell response and gene expression. The presence of GO provided interconnected pores in the composite scaffolds. Adding GO up to 0.1 wt.% significantly enhanced Young’s modulus up to 5.5 MPa and electrical conductivity up to 8.59 S.m-1 (p≤0.05). Additionally, GO improved the vitality of human umbilical vein endothelial cells (HUVECs) compared to the scaffold without GO.  Investigating cell attachment of L929 fibroblasts indicated that the optimal content of GO at 0.05 wt.% can provide better places for cellular nesting due to the appropriate size of pores for cell/material interactions. The increase in the amount of GO up to 0.1 wt.% lead to a significant increase in gene expression of VEGFR-2 compared to the other scaffolds and tissue culture plate. We found that the prepared ALG/0.1GO composite scaffold could be appropriate for further experiments on cardiac tissue engineering applications.