Autologous bionic tissue for inguinal hernia repair

Biomedical Application of Decellularized Scaffolds

Tissue loss and end-stage organ failure are serious health problems across the world. Natural and synthetic polymer scaffold material based artificial organs play an important role in the field of tissue engineering and organ regeneration, but they are not from the body and may cause side effects such as rejection. In recent years, the biomimetic decellularized scaffold based materials have drawn great attention in the tissue engineering field for their good biocompatibility, easy modification, and excellent organism adaptability. Therefore, in this review, we comprehensively summarize the application of decellularized scaffolds in tissue engineering and biomedicine in recent years. The preparation methods, modification strategies, construction of artificial tissues, and application in biomedical applications are discussed. We hope that this review will provide a useful reference for research on decellularized scaffolds and promote their application tissue engineering.

Multifunctional Fluorinated Lubricant-Infused Poly(4-Hydroxybutyrate) (P4HB) Membranes for Full-Thickness Abdominal Wall Defect Repair

Abdominal wall defect caused by surgical trauma, congenital rupture, or tumor resection may result in hernia formation or even death. Tension-free abdominal wall defect repair by using patches is the gold standard to solve such problems. However, adhesions following patch implantation remain one of the most challenging issues in surgical practice. The development of new kinds of barriers is key to addressing peritoneal adhesions and repairing abdominal wall defects. It is already well recognized that ideal barrier materials need to have good resistance to nonspecific protein adsorption, cell adhesion, and bacterial colonization for preventing the initial development of adhesion. Herein, electrospun poly(4-hydroxybutyrate) (P4HB) membranes infused with perfluorocarbon oil are used as physical barriers. The oil-infused P4HB membranes can greatly prevent protein attachment and reduce blood cell adhesion in vitro. It is further shown that the perfluorocarbon oil-infused P4HB membranes can reduce bacterial colonization. The in vivo study reveals that perfluoro(decahydronaphthalene)-infused P4HB membranes can significantly prevent peritoneal adhesions in the classic abdominal wall defects' model and accelerate defect repair, as evidenced by gross examination and histological evaluation. This work provides a safe fluorinated lubricant-impregnated P4HB physical barrier to inhibit the formation of postoperative peritoneal adhesions and efficiently repair soft-tissue defects.

In Vivo Biocompatibility of an Innovative Elastomer for Heart Assist Devices

Cardiac surgical approaches require the development of new materials regardless of the polyurethanes used for pulsatile blood pumps; therefore, an innovative biomaterial, a copolymer of poly(ethylene terephthalate) and dimer fatty acid (dilinoleic acid) modified with D-glucitol, hereafter referred to as PET/DLA, has been developed, showing non-hemolytic and atrombogenic properties and resistance to biodegradation. The aim of this work was to evaluate in vivo inflammatory responses to intramuscular implantation of PET/DLA biomaterials of different compositions (hard to soft segments). Two copolymers containing 70 and 65 wt.% of hard segments, as in poly(ethylene terephthalate) and dilinoleic acid in soft segments modified with D-glucitol, were used for implantation tests to monitor tissue response. Medical grade polyurethanes Bionate II 90A and Bionate II 55 were used as reference materials. After euthanasia of animals (New Zealand White rabbits, n = 49), internal organs and tissues that contacted the material were collected for histopathological examination. The following parameters were determined: peripheral blood count, blood smear with May Grunwald–Giemsa staining, and serum C-reactive protein (CRPP). The healing process observed at the implantation site of the new materials after 12 weeks indicated normal progressive collagenization of the scar, with an indication of the inflammatory–resorptive process. The analysis of the chemical structure of explants 12 weeks after implantation showed good stability of the tested copolymers in contact with living tissues. Overall, the obtained results indicate great potential for PET/DLA in medical applications; however, final verification of its applicability as a structural material in prostheses is needed.

Latest Trends on the Attenuation of Systemic Foreign Body Response and Infectious Complications of Synthetic Hernia Meshes

Throughout the past few years, hernia incidence has remained at a high level worldwide, with more than 20 million people requiring hernia surgery each year. Synthetic hernia meshes play an important role, providing a microenvironment that attracts and harbors host cells and acting as a permanent roadmap for intact abdominal wall reconstruction. Nevertheless, it is still inevitable to cause not-so-trivial complications, especially chronic pain and adhesion. In long-term studies, it was found that the complications are mainly caused by excessive fibrosis from the foreign body reaction (FBR) and infection resulting from bacterial colonization. For a thorough understanding of their complex mechanism and providing a richer background for mesh development, herein, we discuss different clinical mesh products and explore the interactions between their structure and complications. We further explored progress in reducing mesh complications to provide varied strategies that are informative and instructive for mesh modification in different research directions. We hope that this work will spur hernia mesh designers to step up their efforts to develop more practical and accessible meshes by improving the physical structure and chemical properties of meshes to combat the increasing risk of adhesions, infections, and inflammatory reactions. We conclude that further work is needed to solve this pressing problem, especially in the analysis and functionalization of mesh materials, provided of course that the initial performance of the mesh is guaranteed.

Influence of the perfusion bioreactor on Stratified and Distributed approaches for multilayered tissue engineering on biodegradable scaffolds

Despite wide use and approval of poly lactic-coglycolic acid (PLGA) for surgical applications, there have been very few studies on tissue constructions that mimic physiological multilayer structures by combining PLGA scaffolds with tissue engineering. In our study, we developed a bioreactor system to maintain, and to train two types of three-layered vascular-like structures. Then we examined how the perfusion conditions and different tissue engineering approaches affected the formation of the layered structure and degradation of the PLGA scaffolds. In the proposed Distributed Method, the cells were seeded layer by layer on a single scaffold, using spheroids bigger than scaffold fiber gaps and we achieved the higher cell density compared with the Stratified Method where we stacked three PLGA sheets seeded with individual vascular cell types. At the histological level, scaffold degradation was more prominent in the bioreactor compared to the same time interval in vivo. In addition, the faster flow accelerated the decomposition of PLGA fibers. Moreover, bioreactor perfusion culture at lower flow rates could balance cell adhesion and survival, improve the cell density and promote self-organization of multilayer structure with desirable rate of PLGA scaffolds degradation.

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.