Esophagus Tissue Engineering: Hybrid Approach with Esophageal Epithelium and Unidirectional Smooth Muscle Tissue Component Generation In Vitro

The aim of this study was to engineer the two main components of the esophagus in vitro: (a) esophageal epithelium and (b) smooth muscle tissue. Furthermore, (a) survivability of esophageal epithelial cells (EEC) on basement membrane matrix (BMM)-coated scaffolds and (b) oriented smooth muscle tissue formation on unidirectional BMM-coated collagen scaffolds was investigated. Both EEC and smooth muscle cells (SMC) were sourced from Sprague-Dawley rats. The EEC were maintained in vitro and seeded onto BMM-coated 2-D collagen scaffolds. Similarly, smooth muscle cells were obtained using an explants technique and seeded on unidirectional 3-D BMM-coated collagen scaffolds. Cell-polymer constructs for EEC and SMC were maintained in vitro for 8 weeks. Protocols to obtain higher yield of EEC were established. EEC formed a layer of differentiated epithelium after 14 days. EEC survivability on polymers was observed up to 8 weeks. Unidirectional smooth muscle tissue strands were successfully engineered. Esophageal epithelium generation, survivability of EEC on BMM-coated scaffolds, and engineering of unidirectional smooth muscle strands were successful in vitro. The hybrid approach of assembling individual tissue components in vitro using BMM-coated scaffolds and later amalgamating them to form composite tissue holds promises in the tissue engineering of complex organ systems.