Crosslinking of an oesophagus acellular matrix tissue scaffold

Abstract

The oesophagus acellular matrix (EAM) tissue-scaffold has the potential to serve as the foundation for a tissue-engineered oesophagus for repair of ablative defects. Similar to all collagen-based biomaterials, the EAM is subject to enzymatic degradation in vivo. The introduction of exogenous crosslinks to collagen molecules via glutaraldehyde (Glu) is the most accepted method of stabilizing collagen biomaterials, but fixation with Glu incurs adverse effects. Genipin (Gp), a naturally occurring crosslinking agent, has shown to be effective at improving the stability of collagen-based biomaterials with less cytotoxicity and reduced in vivo inflammatory responses than Glu. The aim of this study was to show that crosslinking with Gp improves the stability of the EAM while maintaining minimal biological reactivity and preserving EAM regeneration potential in a rat model. EAMs were crosslinked with Gp and Glu. Uncrosslinked EAMs served as controls. Denaturation temperature measurement and burst-pressure measurement after enzymatic degradation assays were used to determine the effectiveness of crosslinking on in vitro stability. Subcutaneous allograft implantation and oesophageal epithelial cell-seeding studies assessed the crosslinking effects on biological reactivity and regeneration potential, respectively. Both Gp and Glu improved EAM stability. After 30 days of implantation, the EAM elicited a minimal inflammatory response and crosslinking did not increase inflammation. Gp-crosslinked EAMs supported epithelial adhesion and proliferation while Glu-crosslinked EAMs did not. Gp improves the stability of the EAM while maintaining minimal biological reactivity and preserving EAM epithelial proliferation capacity, yielding a tissue scaffold that may form the basis of a durable and biocompatible tissue-engineered oesophagus.