Effect of Silk-Based Hydrogel Topography on Intestinal Epithelial Cell Morphology and Wound Healing In Vitro

Recent advances in the field of biomaterials have suggested that cells cultured on substrates resembling the native tissue mechanical properties, matrix and growth factor composition, and topography can adopt phenotypes that more closely resemble the in vivo tissue compared to cells cultured on non-mimetic constructs. Understanding the effect of culture substrate on in vitro tissue formation is important for bioengineering applications that include mechanistic studies of healthy tissue function and development of disease models. In this work, Caco-2 adenocarcinoma cells were seeded on flat and crypt-like topographies of 3D-printed cytocompatible hydrogels derived from silk fibroin protein. Silk hydrogels were selected for their tunable mechanical properties, their ability to support intestinal cell culture, and their relatively slow degradation profile, which was hypothesized to enable the maintenance of substrate topography during culture. 3D-printed acellular silk hydrogels were found to maintain their shape for over eight weeks in culture medium. Cells were seeded on the silk hydrogel substrates, where it was found that cells both attach and proliferate on substrates with flat and intestinal crypt-like topographies. Future work includes investigating the effect of hydrogel topography on cell morphology using microscopy with visualization of junction molecules by immunostaining. In addition, the effect of topography on the closure of disrupted epithelium will be assessed using a wound scratch assay. It is anticipated that the topographical studies presented will assist in developing more physiologically relevant tissue models that may be used to investigate wound healing in the colon.