PP mesh is a widely used prosthetic material in hernia repair. However, visceral adhesion is one of the worst complications of this operation. Hence, an anti-adhesive PP mesh is developed by coating porous polyvinyl alcohol (PVA) hydrogel on PP surface via freezing-thawing process method. The compressive modulus of porous PVA hydrogel coating is first regulated by the addition of porogen sodium bicarbonate (NaHCO3) at various quality ratios with PVA. As expected, the porous hydrogel coating displayed modulus more closely resembling that of native abdominal wall tissue. In vitro tests demonstrate the modified PP mesh show superior coating stability, excellent hemocompatibility, and good cytocompatibility. In vivo experiments illustrate that PP mesh coated by the PVA4 hydrogel that mimicked the modulus of native abdominal wall could prevent adhesion effectively. Based on this, the rapamycin (RPM) is loaded into the porous PVA4 hydrogel coating to further improve anti-adhesive property of PP mesh. The Hematoxylin and eosin (H&E) and Masson trichrome (MT) staining results verified that the resulting mesh could alleviate the inflammation response and reduce the deposition of collagen around the implantation zone. The biomimetic mechanical property and anti-adhesive property of modified PP mesh make it a valuable candidate for application in hernioplasty.

The effectiveness of polypropylene (PP) mesh is often compromised by severe inflammation. Engineering anti-inflammatory coatings has significant implications for PP mesh to repair unwanted hernias. Here, we presented a facile strategy to develop an anti-fouling coating consisting of zwitterionic poly(carboxybetaine methacrylate) (PCBMA), which could prohibit protein adsorption to endow PP mesh with anti-inflammatory efficacy. The incorporation of PCBMA coating had little impact on the raw features of PP mesh. While the modified mesh PCBMA-PP possessed noticeable hydrophilicity increase and surface charge reduction. The excellent lubricity and surface stability enabled PCBMA-PP to exhibit superior anti-fouling capacity, thus efficiently inhibiting the adsorption of proteins. In vivo experiments showed that incorporating the PCBMA layer could provide PP meshes with outstanding anti-inflammatory effects and tissue compatibility for repairing hernias.

BACKGROUND: This study aimed to establish an animal model of open abdomen (OA) through temporary abdominal closure via different techniques.
METHODS: Adult male Sprague-Dawley rats were randomly divided into three groups: group A (OA with polypropylene mesh alone); group B (OA with polypropylene mesh combined with a patch); and group C (OA with polypropylene mesh and a sutured patch). Vital signs, pathophysiological changes, and survival rates were closely monitored in the rats for 7 days after surgery. Abdominal X-rays and histopathological examinations were performed to assess abdominal organ changes and wound healing.
RESULTS: The results showed no significant difference in mortality rates among the three groups (p > 0.05). However, rats in group B exhibited superior overall condition, cleaner wounds, and a higher rate of wound healing compared to the other groups (p < 0.05). Abdominal X-rays indicated that varying degrees of distal intestinal obstruction in all groups. Histopathological examinations revealed fibrous hyperplasia, inflammatory cell infiltration, neovascularization, and collagen deposition in all groups. Group B demonstrated enhanced granulation tissue generation, neovascularization, and collagen deposition compared to the other groups (p < 0.05).
CONCLUSIONS: Polypropylene mesh combined with patches is the most suitable method for establishing an animal model of OA. This model successfully replicated the pathological and physiological changes in postoperative patients with OA, specifically the progress of abdominal skin wound healing. It provides a practical and reliable animal model for OA research.

Development of an inflammation modulating polypropylene (PP) mesh in pelvic floor repair is an urgent clinical need. This is because PP mesh for pelvic floor repair can cause a series of complications related to foreign body reactions (FBR) in postoperative period. Therefore, we successfully prepared PP composite mesh that can scavenge reactive oxygen species (ROS) and inhibit inflammation to moderate FBR by a simple method. First, a pregel layer was formed on PP mesh by dip coating. Among them, polyurethane with polythioketal (PTK) is an excellent ROS scavenger, and dopamine methacrylamide (DMA) improves the stability of the coating and synergistically scavenges ROS. Then, a composite mesh (optimal PU50-PP) was obtained by photopolymerization. The results showed that the polyurethane gel layer was able to scavenge more than 90% of free radicals and about 75% of intracellular ROS. In vitro, PU50-PP mesh significantly scavenged ROS and resisted macrophage adhesion. After implantation in the posterior vaginal wall of rats, PU50-PP eliminated 53% of ROS, inhibited inflammation (decreased IL-6, increased IL-10), and dramatically reduced collagen deposition by about 64%, compared to PP mesh. Thus, the composite PP mesh with ROS scavenging and anti-inflammatory properties provides a promising approach for mitigating FBR.

Hernia reconstruction is one of the most frequently practiced surgical procedures worldwide. Plastic surgery plays a pivotal role in reestablishing desired abdominal wall structure and function without the drawbacks traditionally associated with general surgery as excessive tension, postoperative pain, poor repair outcomes, and frequent recurrence. Surgical meshes have been the preferential choice for abdominal wall hernia repair to achieve the physical integrity and equivalent components of musculofascial layers. Despite the relevant progress in recent years, there are still unsolved challenges in surgical mesh design and complication settlement. This review provides a systemic summary of the hernia surgical mesh development deeply related to abdominal wall hernia pathology and classification. Commercial meshes, the first-generation prosthetic materials, and the most commonly used repair materials in the clinic are described in detail, addressing constrain side effects and rational strategies to establish characteristics of ideal hernia repair meshes. The engineered prosthetics are defined as a transit to the biomimetic smart hernia repair scaffolds with specific advantages and disadvantages, including hydrogel scaffolds, electrospinning membranes, and three-dimensional patches. Lastly, this review critically outlines the future research direction for successful hernia repair solutions by combing state-of-the-art techniques and materials.

BACKGROUND: A meshoma formation and erosion to the small intestine is rare. Herein, we report one case of a meshoma that was not treated early; causing it to displace and erode the small intestine, with infection, complete control of symptoms was achieved after removal of the infected patch mass, no recurrence of hernia after 2 years of follow-up.
METHODS: A 62-year-old male patient presented with recurrent abdominal pain repeatedly for 1 wk, which has worsened 2 d before admition, accompanied by fever. Five years before presentation he underwent right inguinal hernia Plug and patch repair approach. Two years ago, a computed tomography scan revealed a right lower abdominal mass with soft tissue density, measuring approximately 30 mm × 17 mm, which was diagnosed as meshoma that was not treated. The patient had poorly controlled diabetes in the past year.
CONCLUSIONS: The formation of meshoma is rare, and that if not treated in time it might erode and require resection of the involved organ.

Polypropylene (PP) mesh has been widely used in hernia repair as prosthesis material owing to its excellent balanced biocompatibility and mechanical properties. However, abdominal adhesion between the visceral and PP mesh is still a major problem. Therefore, anti-adhesive PP mesh was designed with poly(vinyl alcohol) (PVA) hydrogel and liposomes drug delivery system. First, PVA hydrogel coating was formed on the surface of PP mesh with freezing-thawing processing cycles (FTP). Subsequently, the lyophilized PVA10-c-PP was immersed in rapamycin (RPM)-loaded liposome solution until swelling equilibrated to obtain the anti-adhesion mesh RPM@LPS/PVA10-c-PP. It was demonstrated that the hydrogel coating can stably fix on the surface of PP mesh even after immersed in PBS solution at 37 °C or 40 °C for up to 30 days. In vitro cell tests revealed the excellent cytocompatibility and the potential to inhibit cell adhesion of the modified PP mesh. Moreover, the anti-adhesive effects of the RPM@LPS/PVA10-c-PP mesh was evaluated through in vivo experiments. The RPM@LPS/PVA10-c-PP mesh exhibited less adhesion than original PP mesh throughout the duration of implantation. At 30 days, the adhesion score of RPM@LPS/PVA10-c-PP mesh was 1.37 ± 0.75, however the original PP was 3 ± 0.71. Furthermore, the results of H&E and Masson trichrome staining proved that the RPM@LPS/PVA10-c-PP mesh showed slighter inflammation response and significant looser fibrous tissue surrounded the PP filaments as compared to the native PP. The current findings manifested that this type of RPM@LPS/PVA10-c-PP might be a potential candidate for anti-adhesion treatment. DATA AVAILABILITY: Data will be made available on request.

The application of polypropylene mesh (PPM) in pelvic organ prolapse (POP) treatment was severely limited by the complications associated with PPM, such as mesh exposure, chronic inflammatory reactions and postoperative hematoma. This study applied a method of fabricating a hydrogel-mesh complex (PPM + TA@GelMA) to cross-link tannic acid (TA) directly with Methacrylate Gelatin (GelMA) hydrogel and thus to form a coating for PPM. This one-step coating modification improved the hydrophilicity and cyto-compatibility of PPM. The hemostatic effect of PPM+TA@GelMA was confirmed through tail amputation test. Through the defect tissue repair experiments in vivo, it was proved that PPM+TA@GelMA had effects of anti-inflammation and promoting tissue repair and regulated the M2 subtype macrophages polarization for tissue repair. The TA-loaded hydrogel coating endued PPM with multiple functions. It is believed that the novel hydrogel-mesh complex and its fabrication method will have great significance in basic research and clinical application.

Background: In this study, a new composite biological mesh named SFP was prepared by combining silk fibroin with polypropylene mesh. The mechanism and clinical application value of the SFP composite mesh were explored. Methods: The fibrous membrane was prepared by electrospinning of silk fibroin. The silk fibrous membrane was adhered to the polypropylene mesh by fibrin hydrogel to make a new composite mesh. The characterizations were verified by structural analysis and in vitro cell experiments. A total of 40 Sprague-Dawley rats were randomly divided into two groups, and 20 rats in each group were implanted with the SFP mesh and pure polypropylene mesh, respectively. The rats were sacrificed in batches on the 3rd, 7th, 14th, and 90th days after surgery. The adhesion degree and adhesion area on the mesh surface were compared, and a histopathological examination was carried out. Results: In vitro cell function experiments confirmed that the SFP mesh had good cell viability. The control group had different degrees of adhesion on the 3rd, 7th, 14th, and 90th days after surgery. However, there was almost no intraperitoneal adhesions on the 3rd and 7th days after surgery, and some rats only had mild adhesions on the 14th and 90th days after surgery in the SFP group. There were statistically significant differences in the postoperative intraperitoneal adhesion area and adhesion degree between the two groups (p < 0.05). Histopathological examination confirmed that the mesenchymal cells were well arranged and continuous, and there were more new capillaries and adipocyte proliferation under the mesenchymal cells in the SFP group. Conclusion: The SFP mesh shows good biocompatibility and biofunction in vitro and in vivo. It can promote the growth of peritoneal mesenchymal cells. The formation of a new mesenchymal cell layer can effectively reduce the extent and scope of adhesion between the mesh and abdominal organs. The SFP mesh will have a good application prospect in the field of abdominal wall hernia repair.

Visualization of the implanted mesh after a pelvic floor repair surgery is important for evaluating mesh-related complications. We made an X-ray-detectable mesh and studied the histocompatibility and toxicity of it.
A thin barium sulfate thread was weaved on a traditional polypropylene mesh to make it X-ray detectable. The cytotoxicity of the mesh was tested by the MTT assay on L929 cell line. The histocompatibility and toxicity of mesh were evaluated in rabbits. Meshes were first implanted intraperitoneally. On postoperative day 7, bloods were tested to estimate the acute toxicity of meshes. After 6 months, rabbits were sacrificed and local inflammatory reaction and tissue regeneration at implantation sites were estimated by the HE stain and Masson stain. In addition, CT scans were performed after surgeries to display the location and shape of implanted meshes.
Compared to the polypropylene mesh group, no significant difference was observed in the X-ray-detectable mesh group on both in vitro cytotoxicity and in vivo acute and chronic toxicity. The amounts of extra cellular matrix between two groups did not differ. Through CT scan and 3D remodeling, the barium sulfate thread clearly revealed the position and shape of the X-ray-detectable mesh, whereas the traditional mesh was invisible under CT scan.
Adding a thin barium sulfate thread on the polypropylene mesh does not change its histocompatibility or toxicity in rabbit model. The barium sulfate thread can effectively show the location and shape of implanted mesh under CT scan.