Preparation and characterization of PHBHHx membranes for use in abdominal surgery

Approximately 90% of patients develop peritoneal adhesions during the recovery process following abdominal surgery. Adhesions are abnormal fibrous or scar tissue resulting from the healing process. To prevent adhesions, non-degradable meshes such as polypropylene and polyethylene terephthalate, as well as degradable meshes like polyglactin, polyglycolic acid, and poly(4-hydroxybutyrate), have been employed. However, degradable meshes are associated with mechanical issues and adhesion-related complications. The aim of this thesis is to prepare and characterize PHBHHx membranes to prevent adhesions after abdominal surgery. To reduce the surface free energy of PHBHHx membranes, inhibit fibroblast adhesion, and prevent activation of clotting factors, the membranes were modified using oleic acid, polyethylene glycol-400 (PEG-400), PEG-8000, and isopropyl myristate. The surface free energies of the PHBHHx membranes, their mechanical properties via dynamic mechanical analysis, and water retention capacities were evaluated. The relationship between these modifications and human fibroblast cell adhesion was analyzed. Additionally, the effects of the modifications on cytokine release, cellular oxidation, and human serum albumin binding capacity were determined. Formulations that do not affect blood clotting factors, do not permit cell adhesion, and do not stimulate pro-inflammatory cytokines were identified.