Adipose-Derived Stem Cells Based on Electrospun Biomimetic Scaffold Mediated Endothelial Differentiation Facilitating Regeneration and Repair of Abdominal Wall Defects via HIF-1α/VEGF Pathway

Recent Advances in Functional Hydrogel for Repair of Abdominal Wall Defects: A Review

The abdominal wall plays a crucial role in safeguarding the internal organs of the body, serving as an essential protective barrier. Defects in the abdominal wall are common due to surgery, infection, or trauma. Complex defects have limited self-healing capacity and require external intervention. Traditional treatments have drawbacks, and biomaterials have not fully achieved the desired outcomes. Hydrogel has emerged as a promising strategy that is extensively studied and applied in promoting tissue regeneration by filling or repairing damaged tissue due to its unique properties. This review summarizes the five prominent properties and advances in using hydrogels to enhance the healing and repair of abdominal wall defects: (a) good biocompatibility with host tissues that reduces adverse reactions and immune responses while supporting cell adhesion migration proliferation; (b) tunable mechanical properties matching those of the abdominal wall that adapt to normal movement deformations while reducing tissue stress, thereby influencing regulating cell behavior tissue regeneration; (c) drug carriers continuously delivering drugs and bioactive molecules to sites optimizing healing processes enhancing tissue regeneration; (d) promotion of cell interactions by simulating hydrated extracellular matrix environments, providing physical support, space, and cues for cell migration, adhesion, and proliferation; (e) easy manipulation and application in surgical procedures, allowing precise placement and close adhesion to the defective abdominal wall, providing mechanical support. Additionally, the advances of hydrogels for repairing defects in the abdominal wall are also mentioned. Finally, an overview is provided on the current obstacles and constraints faced by hydrogels, along with potential prospects in the repair of abdominal wall defects.

Fabrication of Vascular Grafts Using Poly(ε-Caprolactone) and Collagen-Encapsuled ADSCs for Interposition Implantation of Abdominal Aorta in Rhesus Monkeys

The production of small-diameter artificial vascular grafts continues to encounter numerous challenges, with concerns regarding the degradation rate and endothelialization being particularly critical. In this study, porous PCL scaffolds were prepared, and PCL vascular grafts were fabricated by 3D bioprinting of collagen materials containing adipose-derived mesenchymal stem cells (ADSCs) on the internal wall of the porous PCL scaffold. The PCL vascular grafts were then implanted in the abdominal aorta of Rhesus monkeys for up to 640 days to analyze the degradation of the scaffolds and regeneration of the aorta. Changes in surface morphology, mechanical properties, crystallization property, and molecular weight of porous PCL revealed a similar degradation process of PCL in PBS at pH 7.4 containing Thermomyces lanuginosus lipase and in situ in the abdominal aorta of rhesus monkeys. The contrast of in vitro and in vivo degradation provided valuable reference data for predicting in vivo degradation based on in vitro enzymatic degradation of PCL for further optimization of PCL vascular graft fabrication. Histological analysis through hematoxylin and eosin (HE) staining and fluorescence immunostaining demonstrated that the PCL vascular grafts successfully induced vascular regeneration in the abdominal aorta over the 640-day period. These findings provided valuable insights into the regeneration processes of the implanted vascular grafts. Overall, this study highlights the significant potential of PCL vascular grafts for the regeneration of small-diameter blood vessels.

A Review of Advanced Abdominal Wall Hernia Patch Materials

Tension-free abdominal wall hernia patch materials (AWHPMs) play an important role in the repair of abdominal wall defects (AWDs), which have a recurrence rate of <1%. Nevertheless, there are still significant challenges in the development of tailored, biomimetic, and extracellular matrix (ECM)-like AWHPMs that satisfy the clinical demands of abdominal wall repair (AWR) while effectively handling post-operative complications associated with abdominal hernias, such as intra-abdominal visceral adhesion and abnormal healing. This extensive review presents a comprehensive guide to the high-end fabrication and the precise selection of these advanced AWHPMs. The review begins by briefly introducing the structures, sources, and properties of AWHPMs, and critically evaluates the advantages and disadvantages of different types of AWHPMs for AWR applications. The review subsequently summarizes and elaborates upon state-of-the-art AWHPM fabrication methods and their key characteristics (e.g., mechanical, physicochemical, and biological properties in vitro/vivo). This review uses compelling examples to demonstrate that advanced AWHPMs with multiple functionalities (e.g., anti-deformation, anti-inflammation, anti-adhesion, pro-healing properties, etc.) can meet the fundamental clinical demands required to successfully repair AWDs. In particular, there have been several developments in the enhancement of biomimetic AWHPMs with multiple properties, and additional breakthroughs are expected in the near future.

A Review of Abdominal Meshes for Hernia Repair-Current Status and Emerging Solutions

Abdominal hernias are common issues in the clinical setting, burdening millions of patients worldwide. Associated with pain, decreased quality of life, and severe potential complications, abdominal wall hernias should be treated as soon as possible. Whether an open repair or laparoscopic surgical approach is tackled, mesh reinforcement is generally required to ensure a durable hernia repair. Over the years, numerous mesh products have been made available on the market and in clinical settings, yet each of the currently used meshes presents certain limitations that reflect on treatment outcomes. Thus, mesh development is still ongoing, and emerging solutions have reached various testing stages. In this regard, this paper aims to establish an up-to-date framework on abdominal meshes, briefly overviewing currently available solutions for hernia repair and discussing in detail the most recent advances in the field. Particularly, there are presented the developments in lightweight materials, meshes with improved attachment, antimicrobial fabrics, composite and hybrid textiles, and performant mesh designs, followed by a systematic review of recently completed clinical trials.

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.

Abdominal wall hernia repair: from prosthetic meshes to smart materials

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.

Recent trends and advances in type 1 diabetes therapeutics: A comprehensive review

Type 1 diabetes (T1D) is a chronic autoimmune disease characterized by the destruction of pancreatic β-cells, leading to insulin deficiency. Insulin replacement therapy is the current standard of care for T1D, but it has significant limitations. However, stem cell-based replacement therapy has the potential to restore β-cell function and achieve glycaemic control eradicating the necessity for drugs or injecting insulin externally. While significant progress has been made in preclinical studies, the clinical translation of stem cell therapy for T1D is still in its early stages. In continuation, further research is essentially required to determine the safety and efficacy of stem cell therapies and to develop strategies to prevent immune rejection of stem cell-derived β-cells. The current review highlights the current state of cellular therapies for T1D including, different types of stem cell therapies, gene therapy, immunotherapy, artificial pancreas, and cell encapsulation being investigated, and their potential for clinical translation.