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 (50microl) coated grafts (3 x 2mm fragments) were evaluated on a resistance against E. coliin 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. coliin vitro. Furthermore, application of 0.1ml 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.