Int J Med Sci 2013; 10(12):1720-1726. doi:10.7150/ijms.6651 This issue

Research Paper

Prevention of Pleural Adhesions by Bioactive Polypeptides - A Pilot Study

D. Åkerberg, M. Posaric-Bauden, K. Isaksson, R. Andersson, B. Tingstedt

Department of Surgery, Clinical Sciences Lund University, Lund, Sweden.

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Åkerberg D, Posaric-Bauden M, Isaksson K, Andersson R, Tingstedt B. Prevention of Pleural Adhesions by Bioactive Polypeptides - A Pilot Study. Int J Med Sci 2013; 10(12):1720-1726. doi:10.7150/ijms.6651. Available from

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Objective: Postoperative pleural adhesions lead to major problems in repeated thoracic surgery. To date, no antiadhesive product has been proven clinically effective. Previous studies of differently charged polypeptides, poly-L-lysine (PL) and poly-L-glutamate (PG) have shown promising results reducing postoperative abdominal adhesions in experimental settings. This pilot study examined the possible pleural adhesion prevention by using the PL+PG concept after pleural surgery and its possible effect on key parameters; plasmin activator inhibitor-1 (PAI-1) and tissue growth factor beta 1 (TGFb) in the fibrinolytic process.

Methods: A total of 22 male rats were used in the study, one control group (n=10) and one experimental group (n=12). All animals underwent primary pleural surgery, the controls receiving saline in the pleural cavity and the experimental group the PL+PG solution administered by spray. The animals were evaluated on day 7. Macroscopic appearance of adhesions was evaluated by a scoring system. Histology slides of the adhesions and pleural biopsies for evaluation of PAI-1 and TGFb1 were taken on day 7.

Results: A significant reduction of adhesions in the PL+PG group (p<0.05) was noted at day 7 both regarding the length and severity of adhesions. There were no significant differences in the concentration of PAI-1 and TGFb1 when comparing the two groups.

Conclusions: PL+PG may be used to prevent pleural adhesions. The process of fibrinolysis, and fibrosis was though not affected after PLPG administration.

Keywords: postoperative, pleural adhesions, polylysine, polyglutamate, PAI-1, TGFb1.