Cationic polypeptides in a concept of oppositely charged polypeptides as prevention of postsurgical intraabdominal adhesions

Abstract

Background: Two differently charged polypeptides, α-poly-L-lysine and poly-L-glutamate, have previously been shown to effectively reduce postoperative intraabdominal adhesions. Though α-poly-L-lysine showed toxicity in doses too close to the lowest therapeutic dose, the aim in the present study was to investigate the possible antiadhesive effect of another four cationic polypeptides.\rMaterials/Methods: 125 mice were studied with a standardized and reproducible adhesion model and given epsilon poly-L-lysine, lactoferrin, lysozyme and polyarginine respectively in a combination with poly-L-glutamate. Epsilon poly-L-lysine was also tested in different concentrations and as single treatment.\rResults: All four cationic polypeptides above showed a significantly better anti-adhesive effect than the controls receiving saline (p<0.05). Epsilon poly-L-lysine had the best antiadhesive effect of the new substances tested in the experiment. Single treatment with the epsilon poly-L-lysine showed toxic side effects.\rDiscussion: We have shown that epsilon poly-L-lysine, polyarginine, lysozyme and lactoferrin, in descending order, all can reduce postoperative intraabdominal adhesions in mice when combined with poly-L-glutamate. There were side effects of epsilon poly-L-lysine resembling those of α-poly-L-lysine, although less toxic. The antiadhesive effect of epsilon poly-L-lysine did not reach the level of α-poly-L-lysine. Further studies will concentrate on additional investigation, trying to modify the α-poly-L-lysine to lower its toxicity. The less toxic epsilon poly-L-lysine also needs further attention in our research of antiadhesive bioactive polypeptides.