3D microchannel networks by melting alginate hydrogel fibers for cell structures

In this paper, we constructed three dimensional (3D) microchannel networks inside gelatin-based hydrogel towards 3D in vitro cell structures. The 3D in vitro assembly of cells is one of the important techniques to reveal cell growth, differentiation and hystogenesis for applications in tissue engineering, drug screening, and cell characterization. To achieve functional 3D cell structures, vascular networks are necessary to supply oxygen and nutrients to cells, and remove waste product from cells. Alginate hydrogel fibers were employed to construct the microchannel networks like blood vessels in this paper. The patterned hydrogel fibers are embedded in the gelatin-based hydrogel as a mold of microchannels. Cells can be embedded inside the gelatin-based hydrogel. The patterned hydrogel fiber can be melted using standard saline citrate (SSC) buffer and the melted area can be used as vascular networks. The gelatin and agar are mixed to make gelatin-based hydrogel which cannot be melted at 37 °C. The flow inside the melted alginate hydrogel fibers were visualized using fluorescent microbeads and nanobeads. The results validate that the proposed method can be used to make arbitrary patterns of vascular networks inside cell structures and contribute to achieve in vitro 3D cell structures.