An artificial esophagus constructed of cultured human esophageal epithelial cells, fibroblasts, polyglycolic acid mesh, and collagen

We have been developing an artificial esophagus constructed of autologous e sophageal component cells by cell culture. Because human esophageal epithel ial cells are stratified in 20 layers, we attempted to construct an artific ial esophageal epithelium 20 twenty layers thick. In in vitro experiments, we investigated how keratinocyte growth factor produced by fibroblasts acce lerates the proliferation and differentiation of epithelial cells. Esophage al epithelial cells were cultured on collagen sheets in which dermal fibrob lasts (0, 1, 4, 8 x 10(5) cells/ml of collagen) were embedded. In cultured epithelial cells on collagen gels without fibroblasts, 2.1 layer stratifica tion was observed on the 21st day. With 1 x 105 fibroblasts/ml of collagen, 3.0 layer stratification was observed, 5.0 layers with 4 x 10(5) fibroblas ts, and 18.1 layers with 8 x 10(5) fibroblasts. The degree of epithelial ce ll stratification was thus correlated with the number of embedded fibroblas ts. Tubes constructed of a polyglycolic acid mesh frame, a collagen layer w ith esophageal fibroblasts, and an inner layer of esophageal epithelial cel ls were transplanted into muscle flaps of athymic rats, The luminal structu res were observed to be patent without stenosis for 14 days. Histology of t he epithelium revealed 20 layers of stratification, We thus succeeded in co nstructing epithelium similar to human esophageal epithelium. In the future we will attempt to use the tubular structures as a substitute for the esop hagus after esophagectomy.