Inamori Masakazu, Mizumoto Hiroshi, Kajiwara Toshihisa
Department of Chemical Engineering, Faculty of Engineering, Kyushu University , Fukuoka, Japan.
Tissue Eng Part A. 2009 Aug;15(8):2029-37. doi: 10.1089/ten.tea.2008.0403.
Tissue vascularization in vitro is necessary for cell transplantation and is a major challenge in tissue engineering. To construct large and regularly vascularized tissue, we focused on the integration of endothelial cell-covered spheroids. Primary rat hepatocytes were cultured on a rotary shaker, and 100-150 mum spheroids were obtained by filtration. The hepatocyte spheroids were coated with collagen by conjugation with a type 1 collagen solution. Collagen-coated hepatocyte spheroids were cocultured with human umbilical vein endothelial cells (HUVECs), and monolayered HUVEC-covered hepatocyte spheroids were constructed. Without a collagen coat, many HUVECs invaded hepatocyte spheroids but did not cover the spheroid surface. To construct regularly vascularized tissue, we packed HUVEC-covered hepatocyte spheroids in hollow fibers used for plasma separation. Packed spheroids attached to each other forming a large cellular tissue with regular distribution of HUVECs. At day 9 after packing, HUVECs invaded the hepatocyte spheroids and a dense vascular network was constructed. Collagen coating of spheroids is useful for the formation of endothelial cell-covered spheroids and subsequent regular vascularized tissue construction.
体外组织血管化对于细胞移植至关重要，也是组织工程中的一项重大挑战。为构建大型且有规则血管化的组织，我们着重于内皮细胞覆盖的球体的整合。原代大鼠肝细胞在旋转摇床上培养，通过过滤获得100 - 150微米的球体。肝细胞球体通过与I型胶原溶液结合而被胶原包被。胶原包被的肝细胞球体与人脐静脉内皮细胞（HUVECs）共培养，构建出单层HUVEC覆盖的肝细胞球体。没有胶原包被时，许多HUVECs侵入肝细胞球体，但未覆盖球体表面。为构建规则血管化的组织，我们将HUVEC覆盖的肝细胞球体填充到用于血浆分离的中空纤维中。填充的球体相互附着，形成一个具有规则分布的HUVECs的大型细胞组织。填充后第9天，HUVECs侵入肝细胞球体并构建出致密的血管网络。球体的胶原包被有助于形成内皮细胞覆盖的球体以及后续规则血管化组织的构建。
