Tissue-gel electrophoresis enhances antigen removal from porcine aortic valve and bovine pericardium

Background and aim of the study: A tissue-engineered heart valve could provide a living prosthesis with characteristics of an ideal valve replacement. One approach to scaffolding a tissue-engineered heart valve is through the 'decellularization' of xenogeneic tissues. Concerns regarding the completeness of antigen removal associated with current detergent-based decellularization treatments have been raised. The study aim was to evaluate antigen removal from candidate xenogeneic bioscaffolds using a novel tissue-gel electrophoresis (TGE) method. Methods: Porcine aortic valve (PAV) conduit and bovine pericardium (BP) were treated sequentially with hypotonic lysis, sodium dodecyl sulfate (SDS), and TGE. The completeness of antigen removal was evaluated by immunoblot analysis of extractable soluble proteins using rabbit anti-PAV or anti-BP serum. Tissues were also evaluated by hematoxylin and eosin histology. Results: TGE enhanced antigen removal from both the PAV and BP. The effects of TGE were shown to depend on the SDS concentration and voltage (60 versus 120 V), but to be independent of time after 4 h. The effects of TGE were detectable both before and after 96 h aqueous washout. Treatment with 1.0% SDS with TGE (120 V for 4 h) resulted in complete acellularity and no detectable soluble protein antigens from the PAV conduit. Conclusion: TGE is a promising adjunctive decellularization method for generating non-immunoreactive bioscaffolds from xenogeneic tissues.