Tissue-mimicking composite barrier membranes to prevent abdominal adhesion formation after surgery

Postoperative abdominal adhesions often occur after abdominal surgery; barrier membranes which mimic peritoneal tissue can be constructed to prevent abdominal adhesions. To this end, silk fibroin (SF) sheets were coated with polyvinyl alcohol (PVA) and agarose (AGA) at PVA:AGA ratios of 100:0, 70:30, 50:50, 30:70, and 0:100 to create a composite anti-adhesive barrier and allow us to identify a suitable coating ratio. The membranes were characterized in terms of their molecular organization, structure, and morphology using Fourier transform Infrared spectrometer (FT-IR), differential scanning calorimeter (DSC), and scanning electron microscope (SEM), respectively. The physical and mechanical properties of the membranes and their biological performance (i.e., fibroblast proliferation and invasion) were tested in vitro. Each membrane showed both smooth and rough surface characteristics. Membranes coated with PVA:AGA at ratios of 100:0, 70:30, 50:50, and 30:70 exhibited more -OH and amide III moieties than those coated with 0:100 PVA:AGA, which consequently affected structural organization, degradation, and fibroblast viability. The 0:100 PVA:AGA-coated degraded the fastest. Barrier membranes coated with 100:0 and 70:30 PVA: AGA demonstrated reduced fibroblast proliferation and attachment. The membrane coated with 70:30 PVA:AGA exhibited a stable appearance, and did not curl under wet conditions. Therefore, SF sheets coated with 70:30 PVA:AGA show promise as anti-adhesive barrier membranes for further development.

An ex vivo model using human peritoneum to explore mesh-tissue integration

Biological compatibility, in terms of implantation of foreign mesh material in hernia surgery, still needs experimental investigation. The present study develops an experimental model using human peritoneum to study the integration between tissue and different mesh material. The ex vivo model using peritoneal tissue was studied with different mesh material, and integration was monitored over time using microscopy. The peritoneal model could be kept viable in culture for several weeks. Cell migration was seen after 7-10 days in culture and could be further monitored over several weeks. The use of a human artificial model environment enabling the investigation of tissue/mesh integration has, to our knowledge, not been described previously. This proof-of-concept model was developed for the investigation of peritoneal biology and the integration between tissue and different mesh material. It has the potential to be useful in studies on other important biological mechanisms involving the peritoneum.

Summary: This study developed a human experimental model for long-term studies using peritoneal tissue to evaluate integration with different materials, such as synthetic meshes.