The influence of elastin-like recombinant polymer on the self-renewing potential of a 3D tissue equivalent derived from human lamina propria fibroblasts and oral epithelial cells

Three-dimensional epithelial tissue equivalents tend to lose their self-renewing potential progressively during culture as their epithelial cells lose their proliferative capacity with time. Even though the tissue engineered construct can mimic the native tissue well, it rapidly degrades after implantation due to the insufficient number of proliferating cells in the equivalent. In the present study we demonstrate for the first time that the use of an elastin-like recombinant polymer (ELR) engineered to contain the cell adhesion peptide RGD can result in a 3D tissue equivalent with high self-renewing potential, containing as many proliferative cells as the native tissue itself. The 3D tissue equivalent was reconstructed by the coculture of human lamina propria fibroblasts and oral epithelial cells in the nanofibrous ELR-collagen scaffold. Histological, immunohistological and transmission electron microscopic analyses of this oral mucosa equivalent demonstrated the expression of markers characteristic of epithelial proliferation (Ki67) and differentiation (keratin 13), and also the presence of a pluristratified epithelium and an ultrastructurally well-organized basement membrane expressing laminin 332. The synthesis of new extracellular matrix by the fibroblasts was also demonstrated. The scaffold proposed here presents great potential for tissue engineering applications, and also for studies of epithelial proliferation, and epithelial disorders including carcinogenesis.