A prospective, randomised, controlled, double-blind phase I-II clinical trial on the safety of A-Part Gel as adhesion prophylaxis after major abdominal surgery versus non-treated group

Discovery of potential natural dihydroorotate dehydrogenase inhibitors and their synergism with brequinar via integrated molecular docking, dynamic simulations and in vitro approach

The critical function of dihydroorotate dehydrogenase (DHODH) in pyrimidine synthesis attracted a great interest throughout beyond decades. Inhibitors of human DHODH (hDHODH) have validated efficacy for remedy of many immunological diseases. Brequinar and leflunomide are examples of such compounds. However, most of such immunosuppressive medications suffer from a lot of side effects and accompanied by adverse metabolic disturbances and toxicities. So that, immunomodulation utilizing natural products received the attention of many researchers. In this study, computer-aided molecular docking, molecular dynamic (MD) simulations and biochemical testing were utilized to find new pharmacologically active chemical entities from natural sources to combat immunosuppressive diseases. More specifically, Glide docking was used for a structure-based virtual screening of in-house 3D database of compounds retrieved from some traditionally known immunomodulatory plants surveyed from literature. The top five scored plants were found to be Zingiber officinale, Curcuma longa, Glycyrrhiza glabra, Allium sativum and Olea europaea. In vitro hDHODH inhibitory assays illustrated the ability of Allium sativum and silymarin standard hits; specifically, silibinin, to significantly inhibit the hDHODH enzyme. Molecular docking and MD simulations revealed a strong binding of the discovered hits within the active site. Following that, the most promising hits were tested separately with brequinar in a fixed-ratio combination setting to assess their combined effects on hDHODH catalytic inhibition. The binary combination of silibinin and brequinar revealed that in this combination, brequinar could be utilized at a dose 9.33-fold less when compared to its single-use to produce 99% inhibition for hDHODH enzyme. These findings confirmed that this binary mixture is an excellent combination providing better therapeutic effects and lower side effects.

A-Part Gel, an adhesion prophylaxis for abdominal surgery: a randomized controlled phase I-II safety study [NCT00646412]

Background

Intra-abdominal surgical intervention can cause the development of intra-peritoneal adhesions. To reduce this problem, different agents have been tested to minimize abdominal adhesions; however, the optimal adhesion prophylaxis has not been found so far. Therefore, the A-Part^® Gel was developed as a barrier to diminish postsurgical adhesions; the aim of this randomized controlled study was a first evaluation of its safety and efficacy.

Methods

In this prospective, controlled, randomized, patient-blinded, monocenter phase I–II study, 62 patients received either the hydrogel A-Part-Gel^® as an anti-adhesive barrier or were untreated after primary elective median laparotomy. Primary endpoint was the occurrence of peritonitis and/or wound healing impairment 28 ± 10 days postoperatively. As secondary endpoints anastomotic leakage until 28 days after surgery, adverse events and adhesions were assessed until 3 months postoperatively.

Results

A lower rate of wound healing impairment and/or peritonitis was observed in the A-Part Gel^® group compared to the control group: (6.5 vs. 13.8 %). The difference between the two groups was −7.3%, 90 % confidence interval [−20.1, 5.4 %]. Both treatment groups showed similar frequency of anastomotic leakage but incidence of adverse events and serious adverse events were slightly lower in the A-Part Gel^® group compared to the control. Adhesion rates were comparable in both groups.

Conclusion

A-Part Gel^® is safe as an adhesion prophylaxis after abdominal wall surgery but no reduction of postoperative peritoneal adhesion could be found in comparison to the control group. This may at least in part be due to the small sample size as well as to the incomplete coverage of the incision due to the used application.

Trial Registration: NCT00646412

Polyvinyl alcohol hydrogel decreases formation of adhesions in a rat model of peritonitis

BACKGROUND

Adhesion formation after surgery for peritonitis-related conditions, with such associated complications as intestinal obstruction, pain, and infertility, remains an important problem. Applying a liquid barrier intra-peritoneally might reduce initial adhesion formation.

METHODS

A combination of the cecal ligation and puncture model of peritonitis with the side-wall defect (SWD) model of adhesion formation was performed. Forty rats were assigned randomly to receive no barrier or 1 mL or 2 mL of the cross-linked polyvinyl alcohol and carboxymethylcellulose (PVA/CMC) hydrogel A-Part(®) Gel (B. Braun Aesculap AG, Tuttlingen, Germany). After 14 days, the animals were sacrificed, and adhesion formation and abscess formation were scored.

RESULTS

Thirty animals survived, distributed equally among the groups. There were significantly fewer adhesions to the SWD in the PVA/CMC groups (median 0) than in the control group (median 26%-50%) (p<0.05). The median tenacity of the adhesions was significantly higher in the control group (Zühlke score 2) than in the PVA/CMC groups (Zühlke score 0) (p<0.05). The amount and size of intra-abdominal abscesses were not significantly different in the three groups.

CONCLUSION

In this experiment, PVA/CMC hydrogel reduced the amount of adhesions to the SWD and between viscera significantly with equal risk of abscess formation.

A hydrogel for adhesion prevention: characterization and efficacy study in a rabbit uterus model

OBJECTIVE

Postoperative peritoneal adhesions following gynaecological surgery remain a clinically relevant problem. One approach to prevent adhesion formation is to apply physical barriers such as hydrogels.

STUDY DESIGN

A physically crosslinked polyvinyl alcohol and carboxymethylcellulose (PVA/CMC) hydrogel (A-Part) was characterized in vitro. Three different traumatization methods were evaluated in a rabbit uterine study. To determine its anti-adhesion efficacy, the hydrogel was first tested in an in vivo pilot study and then in a larger trial to compare it with icodextrin 4% solution (Adept) and controls.

RESULTS

Rheological measurements showed an increased elasticity of the hydrogel after freezing. In vivo experiments revealed a clear reduction in incidence, extent and severity of adhesions compared to the icodextrin 4% solution and the untreated control group.

CONCLUSIONS

These results warrant further investigation of the PVA/CMC A-Part hydrogel in clinical trials focused on gynaecological procedures.