Evaluation of Collagen-Immobilized Percutaneous Implants

Abstract

A Silastic^R tube, provided with a silicone disk or also a polyethylene sponge covering the disk as a cuff, was fabricated in an attempt to develop a percutaneous device which would not suffer from infection. Following exposure to corona discharge, acrylic acid was graft polymerized onto the surface of the cuff. Then collagen was immobilized covalently on the grafted surface by utilizing the carboxyl groups of the poly(acrylic acid) chains. The collagen immobilization was performed to render the cuff surface tissue-adhesive for preventing the bacterial infection which would occur through the dead space present between the cuff and the epidermal tissue. The device was percutaneously implanted in the back of rabbits to examine epidermal down-growth as well as bacterial infection. Unless the collagen was immobilized, bacterial infection occurred in an early stage after implantation. On the contrary, no epidermal down-growth was observed and infection took place only in one case when the cuff surface was immobilized with collagen. This result indicates that the collagen immobilization is very effective in preventing bacterial infection of the percutaneous device.