Inhibition of vascular prosthetic graft infection using a photocrosslinkable chitosan hydrogel

Background. Despite improvements in surgical techniques and antimicrobial therapies, prosthetic aortic graft infections remain a clinical problem. It is well known that chitosan has strong antibacterial activities to a wide variety of bacteria including Staphylococcus aureus, epidermidis and Escherichia coli (E. coli). The antibacterial activity by adhering a photocrosslinkable chitosan hydrogel to Dacron grafts was investigated in vitro and in vivo using a rabbit model. Materials and methods. The photocrosslinkable chitosan hydrogel (50 mul) coated grafts (3 X 2 mm fragments) were evaluated on a resistance against E. coli in vitro. The graft infections in vivo were also initiated through implantation of a Dacron graft fragment into the infrarenal aorta of a rabbit, followed by a topical inoculation with 10(6) colony-forming units of E. coli. The graft infection was allowed to develop over the following 1 week. Results. The photocrosslinkable chitosan hydrogel-coated grafts exhibited a resistance against E. coli in vitro. Furthermore, application of 0.1 ml photocrosslinkable chitosan hydrogel on the Dacron implant in vivo substantially inhibited graft infection with E. coli. Conclusions. These preliminary results suggested the potential use of a photocrosslinkable chitosan hydrogel in directing graft infection prophylaxis. (C) 2004 Elsevier Inc. All rights reserved.