This project is designed to improve continuous ambulatory peritoneal dialysis (CAPD) catheters by developing an improved exit port that will produce a stable integument seal and greatly reduce the frequency of catheter sepsis. The exit port will have the following feature which are expected to promote an integument seal: 1) the port will fit around catheter tubing and interface with the skin and subcutaneous tissues; 2) its surface will be composed of porous polymers which will allow extensive tissue ingrowth; and 3) all surfaces on the porous polymers will be coated with covalently immobilized cell adhesion proteins to promote rapid and stable integration with epidermal and connective tissue cells. The Phase I results showed that covalently immobilized cell adhesion proteins: 1) greatly improve the growth of both epidermal cells and fibroblasts on coated polymers and 2) reduce bacterial colonization and growth on polymers. To further reduce bacterial colonization while epidermal and connective tissues are integrating with catheter polymers, specific antimicrobial agents will be immobilized. In Phase II, several porous polymers will be coated with cell adhesion proteins and antimicrobial agents and evaluated both in vitro and in vivo for enhanced tissue integration and antimicrobial activity. Then, the most effective polymer/ coating combinations will be assembled into prototype of exit ports which will be implanted percutaneously into miniature pigs.
| Clubb Jr, F J; Clapper, D L; Deferrari, D A et al. (1999) Surface texturing and coating of biomaterial implants: effects on tissue integration and fibrosis. ASAIO J 45:281-7 |
