Abstract: Collagen-containing tissue is cross-linked to provide tissue suitable for use in production of bioprosthetic devices. A cross-linking agent is used having an aliphatic component containing about 8 to 40 carbon atoms and two collagen-reactive groups such as isocyanate, epoxy or n-hydroxysuccinimide. The cross-linking agent may be produced by dimerizing fatty acids, and modifying carboxylic acid group of the fatty acids before or after dimerization to contain collagen-reactive groups. The cross-linked tissue has desirable mechanical and biocompatibility features and a reduced susceptibility to calcification.

Abstract: The disclosed invention relates to the process of fixating tissue to obtain tissue for bioprosthetic applications. The fixating process comprises exposing the tissue to a fluid comprising activated difunctional or polyfunctional acids that can react with amino groups in tissue under mild conditions. Activating moieties include disuccinimidyl moieties, n-hydroxy disuccinimidyl moieties, sulfo-disuccinimidyl moieties, and mixtures thereof. The acid is preferably aliphatic difunctional or polyfunctional acids, more preferably a naturally occurring aliphatic difunctional or polyfunctional acids. Even more preferred is an acid consisting of glutaric, suberic acid, sebacic acid, tartaric acid, or mixtures thereof. The activated difunctional or polyfunctional acids are esters comprising the difunctional or polyfunctional acids and the activating moieties.