THE CHEMICAL PROTECTING GROUP CONCEPT APPLIED IN CROSS-LINKING OF NATURAL TISSUES WITH GLUTARALDEHYDE ACETALS

This work describes the results of the controlled crosslinking of coll agen matrices by glutaraldehyde based on a double protection strategy, glutaraldehyde acetals and lysine protonation due to the acidic condi tions of acetal formation. Materials crosslinked by this approach were characterized by thermal stability comparable to those obtained by co nventional procedures with mechanical properties expected for bioprost hesis manufacture and with a higher stability toward collagenase hydro lysis. The integrity of the microfibrillar structure was confirmed by optical and scanning electronic microscopy. The results indicate that the glutaraldehyde acetals procedure may be of potential use for the c rosslinking of bovine pericardium used in the manufacture of bioprosth etic devices. Advantages may be related to the production of materials with homogeneous crosslinking distributions, associated with better d efinition in the nature of the chemical link that they introduce, due to a better distribution of glutaraldehyde within the tissue matrix be fore the crosslinking reaction is allowed to occur. As a result, mater ials with improved biological and mechanical properties are expected.