Effects of micro-patterns in three-dimensional scaffolds for tissue engineering applications

Micro-patterns, typically fabricated by microelectromechanical systems technologies, have been applied to two-dimensional (2D) environments for tissue engineering applications. Nano-stereolithography, a unique solid freeform technology, is now available to apply micron-sized patterns to three-dimensional (3D) scaffolds in a direct process. Many studies have reported that the micro-patterns, which are smaller than cell sizes, have effects on cell behavior. Thus, we considered that a scaffold incorporating micro-patterns might be more appropriate for tissue engineering applications than non-patterned scaffolds. In this study, we fabricated 3D scaffolds with micro-patterns (micro-pillar and micro-ridge types) on each layer using an NSTL system. In an in vitro study using pre-osteoblast cells, we observed the effects of micro-patterns on cellular behaviors, such as proliferation, adhesion and osteogenic differentiation. The scaffolds with micro-patterns showed significantly improved cell adhesion ability versus a scaffold with no patterning. We also observed that the expression of osteogenic markers, such as ALP and Runx2, increased significantly in scaffolds with micro-pillar and micro-ridge patterns compared with non-patterned scaffolds. Thus, it could be a promising strategy for effective tissue engineering applications to add such micro-patterns on 3D scaffolds. (paper)