Preventing postoperative abdominal adhesions in a rat model with PEG-PCL-PEG hydrogel

Abstract

Background: Poly (ethylene glycol)-poly (ε-caprolactone)-poly (ethylene glycol) (PEG-PCL-PEG, PECE) hydrogel has been demonstrated to be biocompatible and thermosensitive. In this study, its potential efficacy and mechanisms of preventing postsurgical abdominal adhesions were investigated. Results: PECE hydrogel was transformed into gel state from sol state in less than 20 seconds at 37°C. None of the animals treated with the hydrogel (n = 15) developed adhesions. In contrast, all untreated animals (n = 15) had adhesions that could only be separated by sharp dissection (P , 0.001). The hydrogel adhered to the peritoneal wounds, gradually disappeared from the wounds within 7 days, and transformed into viscous fluid, being completely absorbed within 12 days. The parietal and visceral peritoneum were remesothelialized in about 5 and 9 days, respectively. The hydrogel prevented the formation of fibrinous adhesion and the invasion of fibroblasts. Also, along with the hydrogel degradation, a temporary inflammatory cell barrier was formed which could effectively delay the invasion of fibroblasts during the critical period of mesothelial regeneration. Conclusion:The results suggested that PECE hydrogel could effectively prevent postsurgical intra-abdominal adhesions, which possibly result from the prevention of the fibrinous adhesion formation and the fibroblast invasion, the promotion of the remesothelialization, and the hydroflotation effect.

A new bioabsorbable polymer film to prevent peritoneal adhesions validated in a post-surgical animal model

“…Barrier adjuvants are used to prevent adhesions by decreasing the apposition of injured visceral and parietal peritoneum until remesothelialization occurs [ 29 ]. The ideal barrier should not only be anti-adhesive, biocompatible, absorbable, and able to be applied through the laparoscope, but also should remain in place on the traumatized surfaces without sutures or staples, including bleeding surfaces, and not interfere with remesothelialization [ 32 ]. For many years, polymers have been used in the conception of adjuvant barriers including solid membranes, hydrogels or solutions [ 33 ].…”

Prevention of Intraabdominal Adhesions by Local and Systemic Administration of Immunosuppressive Drugs

“…Peritoneal adhesions generally begin to be formed in the early postoperative period. Various agents against fibrinous adhesion formation have been tried with promise results in animal models ( 8 ). Along with these findings, observed incidence of postoperative adhesion-related intestinal obstruction after visceral organ transplantation has remained very low ( 9 , 10 ).…”

Antienflamatuar and antiadhesive effect of clioquinol

“…Postsurgically-activated macrophages release various substances such as cyclooxygenase and lipooxygenase metabolites, plasminogen activator, plasminogen activator-inhibitor, IL-1, IL-6, TNFalpha and collagenase [1,4]. In the presence of these substances, vascular permeability increases and subsequently adhesion formation starts [5,8]. Furthermore, recent studies have reported that inflammatory reactions also cause adhesion via free oxygen radicals and their metabolites [2].…”

“…The most common symptom is chronic abdominal and pelvic pain. Intestinal obstruction and infertility can be observed which may cause a significant loss of the patients' quality of life [3,5]. A second laparotomy for the treatment of adhesions causes enhanced postoperative morbidity and mortality due to the loss of normal anatomical configuration [6].…”