Peritoneum‐Inspired Janus Porous Hydrogel with Anti‐Deformation, Anti‐Adhesion, and Pro‐Healing Characteristics for Abdominal Wall Defect Treatment

Abstract

layers has attracted remarkable attention in recent years for surgical challenge and undesirable treatment outcomes. The destruction of the muscular layer is difficult to be sutured and injury of the serosal membrane could induce obvious viscera adhesion. [5,6] In the past few decades, tension-free repair operation is recommended as the standard treatment for soft-tissue defects like abdominal wall defects, in which different types of patches have been widely used. [1,[7][8][9] Traditional synthetic meshes with high strength, light weight, and anti-deformation (e.g., polypropylene (PP) and polyester meshes) have been widely used for tension-free repair of soft-tissue defects. But these meshes could result in severe visceral adhesion and undesirable wound healing, because of an obvious foreign body reaction (Figure 1a). [10][11][12] One of the most common approaches to solve the problem of visceral adhesion is to develop composite patches with anti-adhesion barriers. [9,13] For example, Parietex composite (PCO) mesh has been successfully designed to prevent visceral adhesion by coating an anti-adhesive collagen-based barrier on polyester mesh. [14,15] Nevertheless, these polyester or PP-based composite meshes could cause undesirable wound healing, due to their inherent unsatisfied inflammation response and lack of suitable microstructure for cells to migrate and grow. [16,17] Moreover, the collagen-based barrier would swell and cause deformation of composite meshes in an abdominal wet environment [18] (Figure 1b). Currently, the Implantable meshes used in tension-free repair operations facilitate treatment of internal soft-tissue defects. However, clinical meshes fail to achieve anti-deformation, anti-adhesion, and pro-healing properties simultaneously, leading to undesirable surgery outcomes. Herein, inspired by the peritoneum, a novel biocompatible Janus porous poly(vinyl alcohol) hydrogel (JPVA hydrogel) is developed to achieve efficient repair of internal soft-tissue defects by a facile yet efficient strategy based on top-down solvent exchange. The densely porous and smooth bottom-surface of JPVA hydrogel minimizes adhesion of fibroblasts and does not trigger any visceral adhesion, and its loose extracellular-matrix-like porous and rough top-surface can significantly improve fibroblast adhesion and tissue growth, leading to superior abdominal wall defect treatment to commercially available PP and PCO meshes. With unique anti-swelling property (maximum swelling ratio: 6.4%), JPVA hydrogel has long-lasting anti-deformation performance and maintains high mechanical strength after immersion in phosphate-buffered saline (PBS) for 14 days, enabling tolerance to the maximum abdominal pressure in an internal wet environment. By integrating visceral anti-adhesion and defect pro-healing with anti-deformation, the JPVA hydrogel patch shows great prospects for efficient internal soft-tissue defect repair.

Multifunctional Microgel-Based Cream Hydrogels for Postoperative Abdominal Adhesion Prevention

“…By combining the advantages of film and liquid barriers, the injectable hydrogel can perfectly cover irregular wounds and has shown potential in abdominal adhesion inhibition after open or laparoscopic surgery . Many types of injectable hydrogels with excellent antifouling adhesive capabilities, such as carboxyl-containing dynamically cross-linked supramolecular polymer–nanoparticle hydrogels, Janus hydrogels, , photocurable catechol-grafted hyaluronic acid (HA) hydrogels, , hotmelt tissue adhesives, bottlebrush inspired injectable hydrogels, cellulose-based thermo-gels, and zwitterionic hydrogels, , were prepared by using natural or synthetic polymers through chemical modification or cross-linking. Although efficacy has been shown, these hydrogel systems may encounter at least some of the following limitations: (1) rapid degradation rate and short retention time; (2) presence of toxic residues of cross-linking agents; (3) the use of ultraviolet irradiation; (4) lack of self-healing or self-fused ability to prevent fragmentation during the injection process; (5) slow hydrogel gelation.…”

Multifunctional “Janus‐Type” Bilayer Films Combine Broad‐Range Tissue Adhesion with Guided Drug Release

“…Very recently, a three-layered Janus adhesive with asymmetric wetting properties developed by Xu et al [23] was found to be successful in keeping the wound area dry while absorbing the wound exudate. Other very recent and highly promising examples from this area are peritoneuminspired porous poly(vinyl alcohol) (PVA) hydrogels for canalizing cellular growth at the desired site, [26] and double-layered (ionically and covalently cross-linked) alginate/chitosan films for advanced tendon healing. [25] These asymmetric materials provide a set of distinct functions for the wound-healthy tissue interface.…”

Smart Hydrogels Bearing Transient Gel–Sol–Gel Transition Behavior Driven by a Biocompatible Chemical Fuel

“…Hydrogels have been demonstrated as a class of promising materials that show enticing applications in biomedicine because of their similarity to biological tissues, of which bioadhesive is one of the most important paradigms. − The dynamic gel–sol–gel transition would be very interesting for detachable and adaptive adhesives, which matches the concept of self-correction proposed by Cheng and Shi et al For instance, the removal of a wound dressing usually leads to uncomfortable pain and secondary damage to the wound. A gentle gel–sol transition may provide a useful solution for this issue.…”