Fabrication of 3D micropatterns with high hosting cell efficiency and their effects on osteogenic differentiation of MSCs

•Different 3D micropatterns were constructed via a modified manufacturing protocol.•The efficiency of cell hosting reached to 90%.•The geometry effect of 3D micropattern on osteogenesis was verified in vivo. 3D micropatterns were suitable template for studying the interactions between materials and cells, but one of the challenges was the low hosting cell efficiency. Thus, 3D micropatterns of the rectangle, triangle, circle and square were fabricated by a novel technology, which limited the growth of stem cells within the 3D micropatterns and achieved a hosting cell efficiency of more than 90%. Further, results of immunofluorescence in vitro and immunohistochemistry in vivo, showed that the expression of osteogenic associated proteins and endonuclear YAP/TAZ of rectangle and triangle 3D micro-patterns groups were higher than circle and square groups, elucidating the molecular mechanism of 3D micro-patterns regulating stem cell differentiation through mechanical signal YAP/TAZ. In conclusion, our 3D micro-patterns of high hosting cell efficiency regulated stem cell differentiation by a pattern-induced mechanical stimulus, affecting the regeneration of bone tissue. This project will provide a feasible paradigm for developing the next generation of 3D-patterns induced tissue engineering materials based on surface micro-nano engineering.