Nanotopography promotes cardiogenesis of pluripotent stem cell-derived embryoid bodies through focal adhesion kinase signaling

Controlling the microenvironment surrounding the pluripotent stem cells (PSCs) is a pivotal strategy for regulating cellular differentiation. Surface nanotopography is one of the key factors influencing the lineage-specific differentiation of PSCs. However, much of the underlying mechanism remains unknown. In this study, we focused on the effects of gradient nanotopography on the differentiation of embryoid bodies (EBs). EBs were cultured on three differently sized nanopillar surfaces (Large, 280–360; Medium, 200–280; Small, 120–200 nm) for spontaneous cardiomyocyte differentiation without chemical stimuli. The large nanotopography significantly promoted cardiogenesis, with increased expression of cardiac markers such as α-MHC, cTnT, and cTnI, and redistributed vinculin expression to the contact area. In addition, the small and medium nanotopographies also influenced EB differentiation, affecting both cardiogenesis and hematopoiesis to varying degrees. The phosphorylation of focal adhesion kinase (FAK) decreased in the EBs on the large nanotopography compared to that in the EBs cultured on the flat surface. The gradient nanotopography with 280–360 nm nanopillars is beneficial for the cardiogenesis of EBs in a FAK-dependent manner. This study provides valuable insights into controlling stem cell differentiation through nanotopographical cues, thereby advancing our understanding of the microenvironmental regulation in stem cell-based cardiac tissue engineering.