Stromal vascular fraction cells as biologic coating of mesh for hernia repair

Coatings for Permanent Meshes Used to Enhance Healing in Abdominal Hernia Repair: A Scoping Review

INTRODUCTION

Hernia meshes are used to reduce recurrence and pain rates, but the rates are still high. This could be improved with coatings of the mesh. This scoping review aimed to provide an overview of mesh coatings used to promote healing in abdominal hernia repair and to report beneficial and unbeneficial effects.

METHODS

We included human and animal studies with abdominal hernias that were repaired with non-commercially coated meshes. We searched Pubmed, Embase, Cochrane Central, LILACS, and CNKI without language constraints.

RESULTS

Of 2933 identified studies, 58 were included: six studies had a total of 408 humans and 52 studies had 2679 animals. The median follow-up was 12 months (range 1-156), and 95% of the hernias were incisional. There were 44 different coatings which included platelet-rich plasma, mesenchymal stem cells, growth factors, vitamin E, collagen-derived products, various polysaccharides, silk proteins, chitosan, gentamycin, doxycycline, nitrofurantoin, titanium, and diamond-like carbon. Mesenchymal stem cells and platelet-rich plasma were the most researched. Mesenchymal stem cells notably reduced inflammation and foreign body reactions but did not impact other healing metrics. In contrast, platelet-rich plasma positively influenced tissue ingrowth, collagen deposition, and neovascularization and had varying effects on inflammation and foreign body reactions.

CONCLUSION

We identified 44 different mesh coatings and they showed varying results. Mesenchymal stem cells and platelet-rich plasma were the most studied, with the latter showing considerable promise in improving biomechanical properties in hernia repair. Further investigations are needed to ascertain their definitive use in humans.

Novel Material Optimization Strategies for Developing Upgraded Abdominal Meshes

Over 20 million hernias are operated on globally per year, with most interventions requiring mesh reinforcement. A wide range of such medical devices are currently available on the market, most fabricated from synthetic polymers. Yet, searching for an ideal mesh is an ongoing process, with continuous efforts directed toward developing upgraded implants by modifying existing products or creating innovative systems from scratch. In this regard, this review presents the most frequently employed polymers for mesh fabrication, outlining the market available products and their relevant characteristics, further focusing on the state-of-the-art mesh approaches. Specifically, we mainly discuss recent studies concerning coating application, nanomaterials addition, stem cell seeding, and 3D printing of custom mesh designs.

A Fibrin Coating Method of Polypropylene Meshes Enables the Adhesion of Menstrual Blood-Derived Mesenchymal Stromal Cells: A New Delivery Strategy for Stem Cell-Based Therapies

Polypropylene (PP) mesh is well-known as a gold standard of all prosthetic materials of choice for the reinforcement of soft tissues in case of hernia, organ prolapse, and urinary incontinence. The adverse effects that follow surgical mesh implantation remain an unmet medical challenge. Herein, it is outlined a new approach to allow viability and adhesion of human menstrual blood-derived mesenchymal stromal cells (MenSCs) on PP surgical meshes. A multilayered fibrin coating, based on fibrinogen and thrombin from a commercial fibrin sealant, was optimized to guarantee a homogeneous and stratified film on PP mesh. MenSCs were seeded on the optimized fibrin-coated meshes and their adhesion, viability, phenotype, gene expression, and immunomodulatory capacity were fully evaluated. This coating guaranteed MenSC viability, adhesion and did not trigger any change in their stemness and inflammatory profile. Additionally, MenSCs seeded on fibrin-coated meshes significantly decreased CD4+ and CD8+ T cell proliferation, compared to in vitro stimulated lymphocytes (p < 0.0001). Hence, the proposed fibrin coating for PP surgical meshes may allow the local administration of stromal cells and the reduction of the exacerbated inflammatory response following mesh implantation surgery. Reproducible and easy to adapt to other cell types, this method undoubtedly requires a multidisciplinary and translational approach to be improved for future clinical uses.

Cell-based therapies for reinforcing the treatment efficacy of meshes in abdominal wall hernias：A systematic review and meta-analysis

To achieve a tension-free repair and reduce the recurrence rate of abdominal wall hernias (AWHs), various kinds of meshes have been applied in surgery. However, these meshes are reported to have problems with adhesion, infection, chronic pain and foreign body sensation. Recently, the introduction of cellular components on meshes seems to provide a new alternative to resolve these problems. This study aimed to evaluate the treatment efficacy of meshes seeded with cells (mesh-cell group) for AWHs, compared to meshes without cells (mesh group). Cochrane Library, Web of Science and PubMed were searched for studies that provided data about meshes, cells and AWHs. Twenty-six studies involving 578 animals were included. We found that the mesh-cell group could better control hernia recurrent than the mesh group (OR = 0.25, 95% CI = 0.15-0.42). Although the mesh-cell group did not reduce the incidence of adhesions (OR = 0.67, 95% CI = 0.26-1.74), it alleviated the extent of adhesions (WMD = -1.48, 95% CI = -1.86 to -1.10). In addition, the capillary density of mesh-cell group was also higher than that of mesh group (WMD = 26.27, 95% CI = 14.45-38.09). For incidence of infection, the two groups had no significant differences (OR = 0.94, 95% CI = 0.39-2.31). On the basis of our current evidence, AWHs were likely to receive a satisfied outcome in animal models when treated by meshes seeded with cells. Future studies with human trial data are needed to validate these findings.

Functionalized Strategies and Mechanisms of the Emerging Mesh for Abdominal Wall Repair and Regeneration

Meshes have been the overwhelmingly popular choice for the repair of abdominal wall defects to retrieve the bodily integrity of musculofascial layer. Broadly, they are classified into synthetic, biological and composite mesh based on their mechanical and biocompatible features. With the development of anatomical repair techniques and the increasing requirements of constructive remodeling, however, none of these options satisfactorily manages the conditional repair. In both preclinical and clinical studies, materials/agents equipped with distinct functions have been characterized and applied to improve mesh-aided repair, with the importance of mesh functionalization being highlighted. However, limited information exists on systemic comparisons of the underlying mechanisms with respect to functionalized strategies, which are fundamental throughout repair and regeneration. Herein, we address this topic and summarize the current literature by subdividing common functions of the mesh into biomechanics-matched, macrophage-mediated, integration-enhanced, anti-infective and antiadhesive characteristics for a comprehensive overview. In particular, we elaborate their effects separately with respect to host response and integration and discuss their respective advances, challenges and future directions toward a clinical alternative. From the vastly different approaches, we provide insight into the mechanisms involved and offer suggestions for personalized modifications of these emerging meshes.