Construction of transplantable artificial vascular tissue based on adipose tissue-derived mesenchymal stromal cells by a cell coating and cryopreservation technique

Abstract

Prevascularized artificial three-dimensional (3D) tissues are effective biomaterials for regenerative medicine. We have previously established a scaffold-free 3D artificial vascular tissue from normal human dermal fibroblasts (NHDFs) and umbilical vein-derived endothelial cells (HUVECs) by layer-by-layer cell coating technique. In this study, we constructed an artificial vascular tissue constructed by human adipose tissue-derived stromal cells (hASCs) and HUVECs (ASCVT) by a modified technique with cryopreservation. ASCVT showed a higher thickness with more dense vascular networks than the 3D tissue based on NHDFs. Correspondingly, 3D-cultured ASCs showed higher expression of several angiogenesis-related factors, including vascular endothelial growth factor-A and hepatic growth factor, compared to that of NHDFs. Moreover, perivascular cells in ASCVT were detected by pericyte markers, suggesting the differentiation of hASCs into pericyte-like cells. Subcutaneous transplantation of ASCVTs to nude mice resulted in an engraftment with anastomosis of host’s vascular structures at two weeks after operation. In the engrafted tissue, the vascular network was surrounded by mural-like structure-forming hASCs, in which some parts developed to form vein-like structures at four weeks, suggesting the generation of functional vessel networks. These results demonstrated that cryopreserved human cells, including hASCs, could be used directly to construct the artificial transplantable tissue for regenerative medicine.