Dry acellular oesophageal matrix prepared by supercritical carbon dioxide

Recently, the use of acellular matrices in tissue engineering has become extremely significant as tissue substitute for organ/tissue reconstruction. In this clinical scenario, banking decellularised organs ready for transplantation would be mandatory for patients with emergency needs. In this work a new process based on supercritical carbon dioxide (SC-CO2) drying technique was investigated for obtaining a dry/preserved decellularized oesophagus. Experiments were performed coupling a detergent enzymatic treatment with two different protocols: (i) SC-CO2 drying; (ii) dehydration in ethanol and a subsequent SC-CO2 drying. The efficiency of the treatments was investigated by monitoring the loss of weight of the treated samples and the maintenance of the extracellular matrix (ECM) architecture, composition and mechanical properties after rehydration. A successful dry acellular matrix was reached in a shorter time using the combined ethanol and SC-CO2 treatment. Histological analysis reported the maintenance of the tissue matrix architecture and the collagen content for all the treated samples, while the preservation of ultrastructural features were confirmed by scanning electron microscopy (SEM). Tensile tests did not show significant differences in terms of fracture strength before and after the supercritical process. Furthermore, the scaffolds demonstrated good biocompatible properties in terms of cell culture viability in vitro. Overall, the results highlighted the potential of this novel technology to obtain a dried acellular matrix for oesophageal regeneration, preserving the extracellular matrix structure of the native tissue.