Biomimetic Assembly of Vascular Endothelial Cells and Muscle Cells in Microgrooved Collagen Porous Scaffolds.

Porous scaffolds can be used to engineer three-dimensional (3D) tissues for tissue repair. Coculture of vascular endothelial cells and the cells of target tissue in porous scaffolds is promising to engineer vascularized tissue. However, it is difficult to induce regeneration of anisotropic tissues such as muscle and nerve that have well-aligned cells, blood vessels, and extracellular matrix (ECM) by using conventional porous scaffolds with homogeneous pore structures. In this study, we developed collagen porous scaffolds with parallel and concave microgrooves by using micropatterned ice template and freeze drying. Vascular endothelial cells and skeletal muscle myoblasts were cocultured on the microgrooved collagen scaffolds and control collagen scaffolds without micropattern structure. When the two types of cells were seeded at a proper ratio and concentration, the 3D microgrooved collagen scaffolds triggered spontaneous cell assembly into anisotropic muscle bundles with well-aligned tubule-like structure. Muscle cells were highly aligned in the tissue bundles, showing high expression of myosin heavy chain and incorporating the aligned tubule structure of vascular endothelial cells. Micropatterned porous scaffolds with microgrooves enabled engineering of anisotropic tissue with well-ordered tubules and could provide a platform for the study of cell assembly in micropatterned material environment.