Immunogenicity of collagenous implants.

Collagenous biomaterials have been used in our laboratory for treatment of decubitus ulcers, tendon/ligament repair and nerve regeneration. Results of previous studies suggest that implants containing bovine type I collagen enhance repair and regeneration of connective tissue found in different organs. The purpose of this paper is to evaluate the immunological response to type I collagen that is cross-linked using either glutaraldehyde or cyanamide treatment. Humoral and cell mediated responses to type I collagen are evaluated in a rabbit model. Results obtained in this study suggest that antibody levels and cell-mediated response to type I collagen are highest in animals exposed to uncross-linked implant materials and these responses are increased by booster injections of the antigen. Antibody titres to cross-linked collagen are significantly lower than those observed for uncross-linked material. Extensive implant cross-linking does not totally eliminate the humoral response and may lead to a cell-mediated reaction.