Abstract
Biological materials are supposed to induce host cells migration and result in organ reconstruction. In implantable artificial organs made of biological materials, however, such a phenomenon is seldom noticed. One of the reasons is a side effect of the crosslinking agent such as glutaraldehyde (GA). GA treatment makes the materials insoluble, less biodegradable, and less antigenic, but the disadvantages are to make the materials more hydrophobic and stiff. Recently, cytotoxity of GA was pointed out in the crosslinked materials even in the long term implantation. In such a poor condition of GA crosslinked materials, host cells cannot reconstruct organs. We introduced a new hydrophilic crosslinking reagent, polyepoxy compounds (PC). instead of GA. Hydrophilicity, softness, and elasticity of the original materials could be preserved after the PC crosslinking. A vascular graft crosslinked with PC and heparinized was newly developed. The graft showed natural tissue compliance and hydrophilicity. Microscopic observations of the graft implanted revealed that the inner surface was covered with endothelial cells. Fibroblasts and smooth muscle like cells infiltrated into the graft wall. They arranged in regular row like that in the native arterial wall. Thus, a new arterial wall was reconstructed in the graft wall. In the control GA crosslinked graft, such a reconstruction inside the graft wall did not occur. These results indicated that the mechanical and chemical properties of the matrix were the important factors for the cell migration and organ reconstruction.
