Design and characterization of a biomimetic stretchable biohybrid scaffold for esophageal regeneration

A variety of pathologic processes or congenital anomalies can negatively affect the characteristics of the esophagus, altering its stiffness or the integrity of the epithelium. In most cases, surgical resection represents the only reliable option. Replacement usually consists of gastric or colonic transplants, often promoting early mortality and morbidity. In the field of tissue engineering, fabrication strategies and materials are thus being explored for creating alternatives to such procedure. The aim of this thesis was the design of a biomimetic stretchable biohybrid substrate for the development of esophageal artificial substitutes, combining synthetic and natural polymers. Meshes were fabricated via fused deposition modelling from polycaprolactone (PCL) with a stent-like geometry; thickness was varied and three different configurations were designed. Finite elements analysis model was defined to evaluate the stress distribution and build up a predictive model for future optimization of the PCL mesh. To enhance the biocompatibility of the construct, meshes were filled with gelatin methacrylate (GelMA) hydrogel. Stability and rheological tests were carried out to analyze the variation of the gel properties depending on solution concentrations, quantity of photo-initiator, methacrylation degree and methacrylation time. Finally, meshes with and without the addition of the hydrogel were mechanically characterized evaluating stiffness compared to the esophageal tissue.