Microfluidics-assisted rapid generation of tubular cell-laden microgel inside glass capillaries

Drug screening using engineered blood vessels (EBVs) faces considerable barriers in approximating the conditions of an in vivo environment. To address this issue, we have introduced a microfluidic system for cell-laden tubular microgels. N-Carboxyethyl chitosan crosslinked with oxidized dextran was used for in situ gelable tubular scaffolds. The microfluidic system consisted of four glass capillaries that generated a coaxial flow of pre-polymer and phosphate buffered solutions. It rapidly produced cell-laden tubular microgels inside glass capillaries. The mechanical strength of the tubular microgels was suitable for their application as EBVs, with a maximum Young's modulus of 12.2 ± 1.9 kPa. In vitro cell studies using human umbilical vein endothelial cells verified the biocompatibility and non-cytotoxicity of the gelation and fabrication process. Thus, in situ gelable cell-laden tubular microgels can be a potential platform for screening drugs to treat blood vessel diseases.