The effect of surfactants, crosslinking agents and L-cysteine on the stabilization and mechanical properties of bovine pericardium.

Abstract

Bovine pericardium (BP) is a collagenous tissue commonly used in cardiovascular applications. However, it suffers from thrombus formation and calcification, the latter generally being related to cell debris and the use of glutaraldehyde (GA). With this in mind, BP was decellularized, crosslinked and grafted with L-cysteine in order to improve its stabilization and mechanical properties. BP was decellularized with ionic and non-ionic surfactants such as sodium dodecyl sulfate (SDS), cetyl trimethyl ammonium chloride (CTMA) or t-octyl phenoxy polyethoxy ethanol (Triton X-100). It was then crosslinked with 1-(3-dimethyl amino propyl)-3-ethyl carbodiimide hydrochloride (EDAC) or GA. Finally, residual aldehyde groups on GA only or EDAC-GA crosslinked pericardium were left to react with L-cysteine (Cys). It was found that the treatment with GA led to a biomaterial with a lower amino-group content than the treatment with EDAC (15 vs. 50 micro;mol/g). The increase in denaturation temperature from 71.2 plusmn; 0.5 to 86.3 plusmn; 0.8 deg;C confirmed that GA was a more effective crosslinking agent than EDAC. In a similar manner, crosslinking with GA increased the percentage of deformation while decreasing their tensile strength. The amount of grafted Cys varied from 3 to 9 micro;mol/g thiol-groups and depended on the concentration of this amino acid and method of crosslinking, but did not modify its physicochemical and mechanical properties.