Search

Background Splenectomy may lead to severe postoperative complications, including sepsis and cancers. A possible solution to this problem is heterotopic autotransplantation of the spleen. Splenic autografts rapidly restore the regular splenic microanatomy in model animals. However, the functional competence of such regenerated autografts in terms of lympho- and hematopoietic capacity remains uncertain. Therefore, this study aimed to monitor the dynamics of B and T lymphocyte populations, the monocyte-macrophage system, and megakaryocytopoiesis in murine splenic autografts. Methods The model of subcutaneous splenic engraftment was implemented in C57Bl male mice. Cell sources of functional recovery were studied using heterotopic transplantations from B10-GFP donors to C57Bl recipients. The cellular composition dynamics were studied by immunohistochemistry and flow cytometry. Expression of regulatory genes at mRNA and protein levels was assessed by real-time PCR and Western blot, respectively. Results Characteristic splenic architecture is restored within 30 days post-transplantation, consistent with other studies. The monocyte-macrophage system, megakaryocytes, and B lymphocytes show the highest rates, whereas the functional recovery of T cells takes longer. Cross-strain splenic engraftments using B10-GFP donors indicate the recipient-derived cell sources of the recovery. Transplantations of scaffolds populated with splenic stromal cells or without them afforded no restoration of the characteristic splenic architecture. Conclusions Allogeneic subcutaneous transplantation of splenic fragments in a mouse model leads to their structural recovery within 30 days, with full reconstitution of the monocyte-macrophage, megakaryocyte and B lymphocyte populations. The circulating hematopoietic cells provide the likely source for the cell composition recovery.

A systems analysis method is considered that agrees with the object-oriented paradigm for setting up information systems. Its procedures are formalized by pattern-theory methods, and also on an original approach to a system as a unit, function, and object, Belgorod State University

The objective of this study was to evaluate physical, mechanical, and biological properties of the polydioxanone (PDO) monofilament meshes and polyglycolide (PGA) polyfilament meshes in comparison with Permacol® implants. In rat experimental model, a 1.5 × 2.0 cm defect in abdominal wall was reconstructed by using the Permacol surgical implant or knitted meshes produced from either PDO monofilament, or PGA multifilament. The implant sites were assessed for the tensile strength and the extents of material resorption, host inflammatory response and host tissue replacement on days 3, 10, 30, or 60 after the surgery. The PDO and PGA meshes were rapidly pervaded by the host connective tissue with elements of skeletal muscle histogenesis. The degree of adhesions was significantly higher in the Permacol group. All of the prostheses underwent resorption, which correlated with gradual decreases in the overall tensile strength of the site and the Col1a1 gene expression level. Elevated expression of Fgf2 gene maintained longer in the PDO group, and the Mmp9 gene expression level in this group was higher than in the other groups. Gene expression levels of inflammatory cytokines were higher in the Permacol group. The foreign body giant cell numbers were lower in the PDO and Permacol groups than in the PGA group. Minimal macrophage infiltration with predominance of M2 cells was observed in the PDO group. Overall, the PDO prosthesis turned out to be significantly better than the PGA or Permacol prostheses by a number of indicators of biocompatibility and efficacy. © 2018 The Authors Journal of Biomedical Materials Research Part B: Applied Biomaterials Published by Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 00B: 000–000, 2018. © 2018 The Authors Journal of Biomedical Materials Research Part B: Applied Biomaterials Published by Wiley Periodicals, Inc.

Umbilical cord-derived multipotent mesenchymal stromal cells (UC-MMSCs) are considered as a strong candidate for cell therapy of lower limb ischemia. Sustained calf muscle ischemia with aseptic inflammatory response was induced in Sprague-Dawley rats by excision of femoral and popliteal arteries. UC-MSCs were injected into the calf muscle on day 7 after surgery. The animals were sacrificed on days 3, 10, and 30 after transplantation. Animals responded to the transplantation by temporary improvement in their locomotor function as assessed by the rota-rod performance test. Measured size of the lesions was significantly smaller in the experimental group than in the control group at all time points throughout the observation. The transplantation stimulated angiogenic processes on day 10 after transplantation. Living transplanted cells were traced for up to 30 days after transplantation, during which time they migrated to the damaged area to be partially eliminated by host macrophages; none of them differentiated into endothelial or smooth muscle cells of blood vessels. Additionally, the transplantation led to the predominance of activated pro-angiogenic and anti-inflammatory M2 macrophages by inhibiting the CD68+ macrophage infiltration and stimulating the CD206+ macrophage activation at the site of injury. A single intramuscular injection of allogeneic umbilical cord-derived mesenchymal stromal cells reproducibly facilitated recovery of structural and functional properties of surgically ischemized calf muscles in a rat. No differentiation of the transplanted cells in vivo was observed. The transplantation negatively regulated inflammation and enhanced tissue repair chiefly by modulating local patterns of macrophage activation. © 2018 Human Stem Cell Institute. All rights reserved.

Nonwoven polycaprolactone materials produced by electrospinning are perspective internal prosthetic implants. Seeding these implants with multipotent mesenchymal stromal cells stimulates the replacement of the prosthesis with recipient's own connective tissue. Electrospinning method was used for producing polycaprolactone matrices differing in thickness, pore diameter, fiber size, and biomechanical properties. Labeled cells were seeded on scaffolds in three ways: (1) static, (2) dynamic, and (3) directed flow of the cell suspension generated by capillary action. Cell distribution on the surface and the interior of the scaffolds was studied; the metabolic activity of cells was measured by MTT assay. Static seeding method yielded fully confluence of cells covered the entire scaffold surface, but the cells were located primarily in the upper third of the matrix. Dynamic method proved to be effective only for scaffolds of thickness greater than 500 microns, irrespective of the pore diameter. The third method was effective only for scaffolds with the pore diameter of 20-30 microns, regardless of the material thickness. Resorbable nonwoven polycaprolactone electrospun materials have appropriate biomechanical properties and similar to native tissue matrix structures for internal prosthesis. The choice of the most effective cell seeding method depends on the spatial characteristics - the material thickness, pore diameter, and fibers size, which are determined by the electrospinning conditions.

Subject Comparison of physico-chemical and biomedical properties of test specimens of mesh implants based on polydioxanone and polyglycolide, looking for application in gynecology and general surgery. Material and methods. In vitro evaluation of cytotoxicity of samples was performed using the MTT assay. Assessment of in vivo biocompatibility prosthesis was performed on outbred rats by simulating polnosloynogo defect of the anterior abdominal wall, which is sutured to the edges of polydioxanone and polyglycolic prosthesis.As a comparison group using the prosthesis on the basis of detsellyulyarizirovannoy dermis (Permacol). The animals were taken from the experiment 3, 10, 30 and 60 days after surgery. Was conducted macroscopic, tenziometricheskoe, morphometric, immunohistochemical and western blot studies. Results. The test prostheses do not possess cytotoxic properties, but in an in vivo experiment showed different intensity of adhesions, the speed and efficiency of integration with the surrounding tissues, preservation of the biomechanical properties of the severity of the inflammatory response. Conclusion. For some indicators of biocompatibility and efficacy of polydioxanone prosthesis was significantly better than prosthesis from polyglycolide and detsellyulyarizirovannoy dermis. © Bionika Media Ltd.