A molded hyaluronic acid gel as a micro-template for blood capillaries

Fabrication of blood capillaries in tissue-engineered tissue is necessary for creating thick three-dimensional (3D) tissue with a high cellular density. For inducing blood capillaries in the tissue in vitro, a molded hyaluronic acid (HA) capillary-shaped gel was made as a template for blood capillaries by photolithography and power free pumping techniques. The fabricated HA capillary-shaped gel was sandwiched between two cell sheets consisting of neonatal normal human dermal fibroblasts (NHDFs), human umbilical vein endothelial cells (HUVECs), or co-cultured NHDFs and HUVECs, and eventually covered with the cells. Although a slight degradation of the HA gel was observed in the sandwiched tissue with HUVEC or NHDF cell sheets, significant degradation of the HA gel was observed in the sandwiched tissue with co-cultured cell sheets. Moreover, by continuing to culture the co-cultured tissue with HA gel, a tube formation was observed at the HA gel site. A sandwiched HA capillary-shaped gel with two cell sheets has a potential for creating blood capillaries in vitro and fabricating vascularized artificial organs.