Cross-linked poly (gamma-glutamic acid) attenuates peritoneal adhesion in a rat model

Background. Poly (gamma-glutamic acid) (PGA) is a naturally occurring biodegradable polymer produced by Bacillus subtilis. PGA is crosslinked by gamma-irradiation to yield crosslinked PGA (XL). XL absorbs large amounts of fluid and forms a biodegradable viscous hydrogel. In the present study, we evaluated the anti-adhesive effect of XL in a rat abdominal wall defect and cecal abrasion model. Methods. Abdominal wall resection and cecal abrasion were carried out in rats (abrasion-no-treatment group, n = 12). In the treatment groups, the following materials were applied: PGA (n = 12), XL (n = 16), hyaluronic acid (HA) (n = 12), Seprafilm (n = 12), and Interceed (n = 10). A week later, adhesion formation was evaluated. Results. Firm adhesions were seen in the abrasion-no-treatment group. XL reduced adhesion formation significantly compared with abrasion-no-treatment, HA, Seprafilm, and Interceed groups. Although not statistically significant, the magnitude of adhesion formation was decreased in the XL group in comparison to the PGA group. Conclusions. We suggest that the anti-adhesive effect of XL was superior to other materials in this rat model. XL application, may have attenuated tissue adhesion by forming a viscous hydrogel over the injured surfaces.