FIGURE 2.

Abdominal adhesion formation at the cecal serosa/peritoneal junction in the rabbit cecal sidewall injury model. This model predictably and quickly generates robust abdominal adhesion formation, with grossly visible adhesions typically present by 7–14 days after surgery. Briefly, the abdominal cavity was accessed through a 12-cm ventral midline incision and bleeding injury was induced on the cecal serosa by abrasion with a sterile dry gauze pad and on the juxtaposed peritoneal inner surface by shallow excision and scraping with a scalpel blade. Approximately ≈2 × 4.5 cm wounds were irrigated with saline and then either treated with topical administration of PuraStat solution or left untreated as Controls before midline incision closure and recovery. At postoperative Day 14, adhesions were significantly more numerous and sizeable at the cecum/peritoneum interface in Control [Panel (A)] animals compared to PuraStat-treated animals [Panel (B)] whose abraded tissue surfaces received 3–12 ml/lesion of PuraStat solution (2.5% RADA16) immediately after wound creation and just prior to abdominal closure. The mean ± SD Total Adhesion Score (average of the scores for extent + strength of the adhesions in both defects per animal) was significantly 76% lower in PuraStat-treated animals at 2.0 ± 3.0 points compared to 8.2 ± 1.9 points in untreated control animals (p = 0.029 by unpaired, two-tailed t-test; maximum possible score = 14 points). The self-assembling RADA16-based hydrogel significantly reduced both the adhesion extent (percent of initial wound area covered by adhesions) and adhesion durability. Remnant PuraStat was observed in 75% of treated animals at the 14-days study terminus.