Tissue and Whole Organ Decellularization: An Evaluation of Cytocompatibility and Mechanics

Extracellular matrix (ECM) scaffolds offer an alternative treatment to repair damaged cardiac tissue by promoting the formation of functional host tissue. While promising, the methods used to manufacture ECM scaffold materials vary widely with different source tissues, detergents, methods of application, and duration. This variability results in differences in the final ECM composition and structure that can lead to inconsistent clinical outcomes. Minimal information exists regarding the physical and biological effects of different detergent treatments used for decellularization upon the resultant ECM scaffold. \ud \ud Cardiac tissue includes both the ECM structure and composition, each of which has reciprocal effects upon cell phenotype and gene expression. This cell-ECM interaction was evaluated by cell deformation and biosynthetic activity and was found to be dependent on localized mechanical coupling to the fiber network. Differences were noted by anatomic location and tissue layer. A therapeutic strategy to replace damaged cardiac tissue with site-specific cardiac derived ECM scaffolds may thus be advantageous. However, different detergent treatments used to decellularize may negatively impact this microstructural complexity and the associated downstream beneficial effects upon tissue remodeling.\ud \ud Two clinically relevant source tissues, urinary bladder and heart, were treated with four detergents commonly used for tissue decellularization: a non-ionic detergent (Triton™ X-100), a zwitterionic detergent (CHAPS), and two ionic detergents (sodium deoxycholate and SDS). For bladder tissue, detergents were applied through immersion and mechanical agitation, and for myocardium, detergents were applied through whole organ retrograde perfusion. The composition, structure, mechanics, and in-vitro cytocompatibility of the resultant ECM materials were characterized. \ud \ud Results show that Triton™ X-100 adequately decellularized bladder tissue but not myocardium during whole organ perfusion. Sodium deoxycholate and SDS were found to be highly effective for decellularization. CHAPS and SDS resulted in a loss of ECM constituents such as GAGs and denatured the collagen fiber network. Failure strength was unaffected by detergent choice. These findings for CHAPS and SDS correlated with a poor in-vitro cytocompatibility. Triton™ X-100 and sodium deoxycholate retained composition, structure, and in-vitro cytocompatibility. This information may assist in the development of rational strategies for effective decellularization of tissues while maintaining ECM structure-function properties