47 research outputs found

    Porous composite materials ZrO[2](MgO)-MgO for osteoimplantology

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    The pore structure and phase composition of ceramic composite material ZrO[2](Mg)-MgO at different sintering temperatures were studied. The main mechanical characteristics of the material were determined and it was shown that they are close to the characteristics of natural bone tissues. It was shown that material structure has a positive effect on the pre-osteoblast cells proliferation. In-vitro studies of pre-osteoblast cells, cultivation on material surface showed a good cell adhesion, proliferation and differentiation of MMSC by osteogenic type

    Porosity and biocompatibility study of ceramic implants based on ZrO[2] and Al[2]O[3]

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    The work studies ZrO[2](MexOy) -based porous ceramics produced from the powdersconsisting of hollow spherical particles. It was shown that the structure is represented by a cellular framework with bimodal porosity consisting of sphere-like large pores and pores that were not filled with the powder particles during the compaction. For such ceramics, the increase of pore volume is accompanied by the increased strain in an elastic area. It was also shown that the porous ZrO[2] ceramics had no acute or chronic cytotoxicity. At the same time, ceramicspossess the following osteoconductive properties: adhesion support, spreading, proliferation and osteogenic differentiation of MSCs

    Porosity and biocompatibility study of ceramic implants based on ZrO[2] and Al[2]O[3]

    Get PDF
    The work studies ZrO[2](MexOy) -based porous ceramics produced from the powdersconsisting of hollow spherical particles. It was shown that the structure is represented by a cellular framework with bimodal porosity consisting of sphere-like large pores and pores that were not filled with the powder particles during the compaction. For such ceramics, the increase of pore volume is accompanied by the increased strain in an elastic area. It was also shown that the porous ZrO[2] ceramics had no acute or chronic cytotoxicity. At the same time, ceramicspossess the following osteoconductive properties: adhesion support, spreading, proliferation and osteogenic differentiation of MSCs

    Perspectives of growth of economic security by clustering of small innovation enterprises

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    The authors analyze the notion, sense, criteria, and indicators of evaluation of economic security and perform the evaluation of economic security of modern economic systems with the help of the offered methodology, which leads to the conclusion that one of the most successful countries are characterized by low level of economic security; therefore, there is a necessity for the search for perspectives of the increase of economic security. As a tool for increasing economic security, clustering is offered. The authors performed the structural analysis of formation of modern clusters and allowed allocating the problems of clustering which can be solved by clustering of small innovational enterprises. It is necessary that small innovational enterprises participate in the development of the program; their joint projects should at least concern, or, even better, solve their common problems (which will increase the competitiveness of cluster, as small innovational enterprises are connected by chains of value added with the same large companies); small innovational enterprises should participate – within the limits of their competencies – in the formation of the program of cluster development; there should be no artificial disunion between clusters of large enterprises and clusters of small innovational enterprises (which requires creation of common list of clusters). As a result of the research, the authors come to the conclusion that cluster is a form of increasing competitiveness within one country and in the global market, which stipulates the growth of national economic security. The highest efficiency of cluster is achieved by clustering small innovational enterprises, which stipulates the optimal level of competition in a cluster and leads to creation of innovations – which is a moving force of development of modern economy and the basis for economic security.peer-reviewe

    Vitamin D binding protein polymorphysm in patients with acute coronary syndrome in kaliningrad region

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    BACKGROUND: Vitamin D binding protein is a main vitamin D carrier in serum. It also has an impact on macrophagial function. Role of vitamin D and macrophages in the pathogenesis of atherosclerosis is scientifically proven but there is lack of data on vitamin D binding protein in this regard. AIMS: To evaluate the vitamin D binding protein polymorphism in patients with acute coronary syndrome without diabetes mellitus, autoimmune diseases and malignant tumors. Determine correlation, if there is, between vitamin D binding protein allele and features of acute coronary syndrome among this patient group. MATERIALS AND METHODS: It is a cross-sectional observational study. Study subjects are patients with acute coronary syndrome. Exclusion criteria are the presence of diabetes mellitus, autoimmune diseases and malignant tumors. In all participants were evaluated: predisposing factors for heart diseases, CBC, biochemical blood test, troponin, coronarography, echocardiography. The study lasted for 5 months from November 2017 until March 2018. Primary end point – assessment of vitamin D binding protein polymorphysm in this group of patients with acute coronary syndrome by means of vitamin D binding protein gene sequencing. 50 patients were enrolled into this study who were urgently admitted to hospital and diagnosed with acute coronary syndrome. Among them – 36 males and 14 females. Mean age was 60 (55;66) years. All participants were sequenced for single nucleotide polymorphysm in VDBP p.T436K (rs4588) and P.432E (rs7041). RESULTS: Gene polymorphysms of interest were found in 43 patients among 50 enrolled. Haplotype Gc1s/2 (rs7041G-rs4588A) was found in 7 (14%) patients, Gc2 (rs7041T-rs4588A) — in 9 (18%) patients, Gc1s (rs7041G-rs4588C) – in 20 (40%) patients, Gc1f (rs7041T-rs4588C) in 14 (28%). Coronarography showed that coronary artery occlusions obstructing more than 50% of vessel lumen was found in 16 patients; obstruction greater than 90% was seen in 8 patients; total occlusion – in 4 patients. CONCLUSIONS: In patient group with acute coronary syndrome prevalence of vitamin D binding protein gene polymorphysm was high – in 86% of participants. The features of Gc2 haplotype were higher frequency of recurrent myocardial infarction and total coronary artery occlusion, as well as tendency to decreased serum vitamin D3 (25(OH)D) levels

    The role of Leu260Phe polymorphism of the receptor gene to GLP-1 incretin in the pathogenesis of diabetes type 2 diabetes with obesity

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    BACKGROUND: Glucagon-like peptide-1 (GLP-1) stimulates the proliferation of β-cells, enhances their resistance to apoptosis and increases glucose-dependent insulin secretion. AIMS: Study of the relationship of Leu260Phe polymorphism (rs1042044) of the GLP-1R gene with postprandial hormone production (C-peptide, insulin, ghrelin, GLP-1) in obese patients with type 2 diabetes. MATERIALS AND METHODS: A total of 174 patients, 82 patients with obesity with type 2 diabetes (BMI=40.4±14.3 kg/m2)and 92 conditionally healthy donors (BMI=22.6±2.7 kg/m2) were studied. The material for the study was venous blood taken on an empty stomach and 60 minutes after the test breakfast. Genotyping was performed by PCR using the sets for determining polymorphism (rs1042044) of the GLP-1R gene (Sintol) and the amplificator (CFX96 BioRad, USA). Plasma hormone levels were evaluated by flow fluorimetry (Bio-PlexProteinAssaySystem, Bio-Rad, USA) using commercial test systems (Bio-PlexProHumanDiabetes 10-Plex Assay, Bio-Rad, USA). Statistical analysis and graphs were obtained at R Statistical Software. RESULTS: A violation of postprandial production of GLP-1 and ghrelin after a test breakfast in obese patients with type 2 diabetes was found. A postprandial increase in C-peptide levels of 3.25[1.83;4.16] ng/ml and insulin 3048 [1978;4972] ng/ml in carriers of the CC genotype compared with carriers of the CA genotype in the group of patients with obesity with type 2 diabetes type In carriers of the CA genotype, there was a decrease in the C-peptide level of 2.21 [1.8;2.49] ng/ml and insulin 1462 [1146; 2304] ng/ml with a constant concentration of GLP-1. The postprandial level of ghrelin in carriers of the CA genotype of the Leu260Phe polymorphism increased to 118[96.1;157] ng/ml compared to carriers of the AA 98 genotype [86; 109] ng/ml. CONCLUSION: The presence of the CC genotype of the Leu260Phe polymorphism of the GLP-1 receptor gene is associated with an increase in postprandial plasma levels of C-peptide and insulin in obese patients with type 2 diabetes, and the CA genotype with a decrease in these indicators and an increase in ghrelin content

    Water-Based Suspensions of Iron Oxide Nanoparticles with Electrostatic or Steric Stabilization by Chitosan: Fabrication, Characterization and Biocompatibility

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    Present day biomedical applications, including magnetic biosensing, demand better understanding of the interactions between living systems and magnetic nanoparticles (MNPs). In this work spherical MNPs of maghemite were obtained by a highly productive laser target evaporation technique. XRD analysis confirmed the inverse spinel structure of the MNPs (space group Fd-3m). The ensemble obeyed a lognormal size distribution with the median value 26.8 nm and dispersion 0.362. Stabilized water-based suspensions were fabricated using electrostatic or steric stabilization by the natural polymer chitosan. The encapsulation of the MNPs by chitosan makes them resistant to the unfavorable factors for colloidal stability typically present in physiological conditions such as pH and high ionic force. Controlled amounts of suspensions were used for in vitro experiments with human blood mononuclear leukocytes (HBMLs) in order to study their morphofunctional response. For sake of comparison the results obtained in the present study were analyzed together with our previous results of the study of similar suspensions with human mesenchymal stem cells. Suspensions with and without chitosan enhanced the secretion of cytokines by a 24-h culture of HBMLs compared to a control without MNPs. At a dose of 2.3, the MTD of chitosan promotes the stimulating effect of MNPs on cells. In the dose range of MNPs 10-1000 MTD, chitosan "inhibits" cellular secretory activity compared to MNPs without chitosan. Both suspensions did not caused cell death by necrosis, hence, the secretion of cytokines is due to the enhancement of the functional activity of HBMLs. Increased accumulation of MNP with chitosan in the cell fraction at 100 MTD for 24 h exposure, may be due to fixation of chitosan on the outer membrane of HBMLs. The discussed results can be used for an addressed design of cell delivery/removal incorporating multiple activities because of cell capability to avoid phagocytosis by immune cells. They are also promising for the field of biosensor development for the detection of magnetic labels

    Adipokines in metabolic processes regulating during obesity treatment

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    Bariatric surgery serves as a model for the assessment of the relationship between body mass index (BMI) reduction and changes in adipokine production and for exploring the endocrine function of the pancreas in patients who do not have the proximal part of the small intestine. Aim.  of the study was to assess the biochemical parameters and plasma levels of adipokines [adiponectin, adipsin, leptin, plasminogen activator inhibitor (PAI-1), resistin and visfatin], insulin, C-peptide, ghrelin and incretins [glucose insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1)] in patients with morbid obesity after surgery (gastric bypass) and therapeutic correction. Materials and methods. A total of 75 patients (34 men and 41 women; age range: 24?67 years) diagnosed as obese were divided into two groups according to the treatment they received. Biochemical analysis was performed to estimate carbohydrate and lipid metabolism rates and plasma levels of adipokines (adiponectin, adipsin, leptin, PAI-1, resistin, visfatin), insulin, C-peptide, ghrelin and incretins (GIP and GLP-1) using the flow fluorometry. Results. Surgical treatment of obesity resulted in a significant decrease in BMI (from 45.67?9.87 to 32.45?5.35 kg/m2,

    Nanoscale Electrical Potential and Roughness of a Calcium Phosphate Surface Promotes the Osteogenic Phenotype of Stromal Cells

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    Mesenchymal stem cells (MSCs) and osteoblasts respond to the surface electrical charge and topography of biomaterials. This work focuses on the connection between the roughness of calcium phosphate (CP) surfaces and their electrical potential (EP) at the micro- and nanoscales and the possible role of these parameters in jointly affecting human MSC osteogenic differentiation and maturation in vitro. A microarc CP coating was deposited on titanium substrates and characterized at the micro- and nanoscale. Human adult adipose-derived MSCs (hAMSCs) or prenatal stromal cells from the human lung (HLPSCs) were cultured on the CP surface to estimate MSC behavior. The roughness, nonuniform charge polarity, and EP of CP microarc coatings on a titanium substrate were shown to affect the osteogenic differentiation and maturation of hAMSCs and HLPSCs in vitro. The surface EP induced by the negative charge increased with increasing surface roughness at the microscale. The surface relief at the nanoscale had an impact on the sign of the EP. Negative electrical charges were mainly located within the micro- and nanosockets of the coating surface, whereas positive charges were detected predominantly at the nanorelief peaks. HLPSCs located in the sockets of the CP surface expressed the osteoblastic markers osteocalcin and alkaline phosphatase. The CP multilevel topography induced charge polarity and an EP and overall promoted the osteoblast phenotype of HLPSCs. The negative sign of the EP and its magnitude at the micro- and nanosockets might be sensitive factors that can trigger osteoblastic differentiation and maturation of human stromal cells
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