Mechanism of crosslinking of proteins by glutaraldehyde III. Reaction with collagen in tissues.

Bovine pericardium, a dense collagenous connective tissue, was crosslinked with glutaraldehyde using different modalities of fixation. The degree of crosslinking was evaluated as a function of the ability of CNBr and pronase to solubilize collagen. Our results suggest that glutaraldehyde fixes primarily the surface of the fibers and creates a polymeric network which hinders the further crosslinking of the interstitium of the fiber. When a low concentration of glutaraldehyde was used, a slow time-dependent crosslinking process was observed. This slow process is maintained over a long period of time, greatly beyond that required for the actual penetration of glutaraldehyde to occur.