Biomechanical and morphological study of a new elastic mesh (Ciberlastic) to repair abdominal wall defects

A bionic 3D-printed hydrogel microneedle of composite mesh for abdominal wall defect repair

The use of mesh repair is a frequently employed technique in the clinical management of abdominal wall defects. However, for intraperitoneal onlay mesh (IPOM), the traditional mesh requires additional fixation methods, and these severely limit its application in the repair of abdominal wall defects. We drew inspiration from the adhesion properties of mussels for the present study, functionalized carboxymethyl cellulose (CMC) with dopamine (DA), and added polyvinyl alcohol (PVA) to the composite to further improve the wet adhesive ability of hydrogels. The CMC-DA/PVA hydrogel microneedles (MNs) were fabricated using an inverse molding technique, incorporating a 3D-printed thermoplastic polyurethane mesh to enhance mechanical strength. The tensile test and porcine skin adhesion test demonstrated that the hydrogel mesh exhibited satisfactory mechanical properties and adhesion in vitro, thus replacing the traditional fixed mesh in the treatment of rat full-thickness abdominal wall defects. The results of animal experiments revealed that the hydrogel mesh promoted the growth of new granulation tissue and inhibited inflammatory responses, thereby paving the way for a novel approach in treating full-thickness abdominal wall defects.

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.

Structural differences and architectural features of two different polypropylene slings (TVT-O and I-STOP) have no impact on biocompatibility and tissue reactions

Introduction

To evaluate the impact of design features of the synthetic mid-urethral slings on tissue integrity and inflammatory responses.

Material and methods

In total 30 female Sprague-Dawley rats were implanted with type I monofilamentous, macroporous polypropylene meshes: Gynecare TVT-Obturator tape^® (Ethicon Inc., Johnson & Johnson, Somerville, NJ, USA) and I-STOP^® (CL Medical Inc., Lyon, France). All animal groups were sacrificed at set time intervals – 6 weeks, 3 months, 6 months, 9 months and 12 months – and the abdominal wall was harvested with mesh strips for histological evaluation.

Results

All mesh strips appeared to be well incorporated into the abdominal wall, and no signs of shrinkage was noticed. All specimens showed a thin/delicate, loose, fibrous interface between the synthetic graft plate and abdominal wall, along with mild inflammatory reactions from 6 weeks to 12 months.

Conclusions

Both mesh brands induced comparable, minimal foreign body reactions and integrated well into the host tissues despite differences in architectural features. TVT-O^® and I-STOP^® evoked similar low-grade inflammatory responses up to 12 months in this animal model.

Structural differences and architectural features of polypropylene slings used in this study have had no impact on tissue integrity and inflammatory responses.