INTERACTIONS BETWEEN SKELETAL SYSTEM AND MACROPHAGES IN HOMEOSTASIS AND BONE INJURY

New insights about close connection between skeletal and immune systems have expanded vistas of modern medicine and tissue engineering. Intensive progress of osteoimmunology enabled the understanding of processes related to bone tissue from a completely new angle, both in physiological and pathological conditions. In this respect, macrophages stand out as cells which affect bone through the ability to secrete a range of different cytokines. Macrophages’ activation is directed by environmental conditions which determine the phenotype and function of these cells. Acquired phenotypic and functional characteristics of macrophages are changed according to changes in their environment. Thanks to these abilities, macrophages have great impact on bone development, bone homeostasis and osteoreparatory process. During bone development, macrophages can affect osteoblast differentiation and matrix mineralization. Coordinated action of osteoclasts and osteoblasts is important in bone tissue remodeling process. Also, during osteoreparation macrophages are among the first cells that will come to the site of bone injury. Their impact on bone is particularly visible during inflammatory phase of fracture healing. Better understanding of mechanisms by which macrophages exert their influence on bone would be an important step in approach to more specific therapies that would modulate activity of these cells and might accelerate healing of bone defects

The isolation, analytical characterization by HPLC-UV and NMR spectroscopy, cytotoxic and antioxidant activities of baeomycesic acid from Thamnolia vermicularis var. subuliformis

The aim of this work was the analytical characterization of the β-orcinol depside, baeomycesic acid in lichens extracts. The extract of Thamnolia vermicularis var. subuliformis was analyzed by the two different methods, namely HPLC-UV and 1H NMR analysis. The results showed that baeomycesic acid was the most abundant depside in the lichens. These results could be of use for rapid identification of this metabolite in other lichen species. Besides baeomycesic acid, three depsides and one monocyclic phenolic compound were isolated from the lichen extract on the chromatographic column. The structure of baeomycesic acid was confirmed by HPLC-UV and spectroscopic methods. In addition, antioxidant and cytotoxic activities of baeomycesic acid were determined. The result of the testing showed that baeomycesic acid exhibited a moderate radical scavenging activity (IC50 = 602.10 ± 0.54 μg/mL) and good cytotoxic activity. This is the first report of detailed analytical characterization, isolation, as well as antioxidant and cytotoxic activities of baeomycesic acid from Thamnolia vermicularis. These results may be helpful in future industrial production of herbal medicines that include this important natural product

Osteogenic potential of freshly isolated cells of adiposederived mesenchymal fraction applied with nanoparticles

The aim of this study was to investigate the osteogenic potential of freshly isolated adipose tissue-derived mesenchymal stromal/stem cells (ASCs) in bone regeneration of rabbit calvaria defects. ASCs were applied together with calcium phosphate-poly-DL-lactide-co-glycolide (CPPLGA) nanoparticles that are mixed in an appropriately prepared blood clot (BC). Parallelly were analysed defects filled with fragmented adipose tissue (FAT) instead of ASCs, with CP-PLGA in BC, and only with nanoparticles. Bone density in defects was measured after I, III and VI weeks, and histological examination was done after IV and VIII weeks after filling defects. Approach to assisted osteoregeneration which is based on the use of fresh non-induced ASCs has proven to be promising due to the favorable effect on bone regeneration and simplicity of their application

Hemijski sastav i biološka aktivnost ekstrakta semena šljive

The aim of this paper was to estimate the biological activity of the plum seed extract and to define the chemical composition by using the ESI-MS method. During the investigation of the antioxidant activity, the extract showed a better ability to inhibit DPPH radicals compared with amygdalin standard. The results of the antimicrobial study indicate that the extract has a greater effect on Gram-negative bacteria compared with amygdalin. Gram-positive bacteria and fungi remained resistant in both cases. Unlike amygdalin, the extract showed a greater antimicrobial activity against the same microbiological strains. Amygdalin was isolated from the extract before the investigation of antiproliferative activity against MDA-MB-361, MDA-MB-453, HeLa and LS174 cell lines using MTT assay. Unlike the MDA-MB-453 cell line, the activity of standard and isolated amygdalin was not observed at the concentrations lower than 400 μg cm-3 on MDA-MB-361 cell line. The isolated amygdalin has not shown the activity in other cell lines. The antiproliferative activity of amygdalin standard was also noticed on HeLa and LS-174 cell lines at the concentrations of 333.27 and 333.17 μg cm-3, respectively.Cilj ovog rada bila je procena biološke aktivnosti ekstrakta semena šljive i definisanje hemijskog sastava primenom ESI-MS metode. Tokom ispitivanja antioksidativne aktivnosti, ekstrakt je pokazao bolju sposobnost inhibiranja DPPH radikala u poređenju sa standardom amigdalina. Rezultati antimikrobne studije pokazali su da ekstrakt ima veći uticaj na rast Gram-negativnih bakterija u odnosnu na amigdalin. Gram-pozitivne bakterije i gljivice ostale su rezistentne u oba slučaja. Za razliku od amigdalina, ekstrakt je pokazao veću antimikrobnu aktivnost na iste sojeve mikroorganizama. Amigdalin je izolovan iz ekstrakta pre ispitivanja antiproliferativne aktivnosti na MDA-MB-361, MDA-MB-453, HeLa i LS174 ćelijskim linijama upotrebom MTT testa. Za razliku od MDA-MB-453 ćelijskih linija, aktivnost standarda i izolovanog amigdalina nije uočena na MDA-MB-361 ćelijskim linijama pri koncentracijama nižim od 400 μg cm-3. Izolovani amigdalin nije pokazao aktivnost na ostalim ćelijskim linijama. Antiproliferativna aktivnost standarda amigdalina uočena je i na HeLa i LS-174 ćelijskim linijama pri koncentracijama 333.27 i 333.17 μg cm-3, respektivno

Nanoparticles Ca/Co-HAp in the treatment of weakened bones jaw tegmenta

The lack of bone in the jaw tegmenta inflicts major problem and leads to an inability to adequately treat stomatoprosthetic patients. If the bone tissue damage is minor, the balanced activities of osteoblasts and bone osteoclasts can repair it independently. If the damage is bigger it is necessary to support the biological potential to repair the bone, and for that reason nanoparticle\ud biomaterial Ca / Co-HAp was used in this study. The research was done on rats with uniform anatomical and physiological characteristics. Assessment of repair and consolidation of the jaw bone tegmenta was performed by istomorphometric and SEM analysis. The best results were obtained in the experimental group of animals where the Ca / Co-Hap was mixed with autologous\ud plasma. Following the implementation of the above mentioned nanocomposites, a significant formation of new bone was evident on the SEM analysis, as well as the rising of histomorphometric parameters of bone formation, which indicates that the Ca / Co-HAp nanocomposite is the material of choice for the rapid regeneration and repair of bone jaw tegmenta

Nanoparticles Ca/Co-HAp in the treatment of weakened bones jaw tegmenta

The lack of bone in the jaw tegmenta inflicts major problem and leads to an inability to adequately treat stomatoprosthetic patients. If the bone tissue damage is minor, the balanced activities of osteoblasts and bone osteoclasts can repair it independently. If the damage is bigger it is necessary to support the biological potential to repair the bone, and for that reason nanoparticlebiomaterial Ca / Co-HAp was used in this study. The research was done on rats with uniform anatomical and physiological characteristics. Assessment of repair and consolidation of the jaw bone tegmenta was performed by istomorphometric and SEM analysis. The best results were obtained in the experimental group of animals where the Ca / Co-Hap was mixed with autologousplasma. Following the implementation of the above mentioned nanocomposites, a significant formation of new bone was evident on the SEM analysis, as well as the rising of histomorphometric parameters of bone formation, which indicates that the Ca / Co-HAp nanocomposite is the material of choice for the rapid regeneration and repair of bone jaw tegmenta

Hydroxyapatite and hydroxyapatite substituents in strengthening of the jaw bone tegmenta

In recent years, calcium hydroxyapatite (HAp) and its substituents are increasingly used in dentistry and medicine. The influence of nanoparticles Ca / Co-HAp in strengthening weak osteoporotic bone jaw tegmenta was tested in an experimental model. The study was conducted on Wistar soy rats, aged 6-8 weeks. The biomaterial was implanted in the osteoporoticly weakened mandible of these animals. The best results in the strengthening of the lower jaw bone tegmenta were achieved 24 weeks after implantation of hydroxyapatite nanoparticles in which the calcium ion was substituted with 12% of cobalt ions. Histochemical parameters of bone synthesis were in a statistically significant increase. SEM analysis showed a high degree of osteogenetic ability of nano-particulate material implanted in the bone defect

Hemolytic activity of bioactive nanocomposites

Huge range of tested biomaterials in recent decades has emerged as an ideal scaffold for cell growth, but few have demonstrated clinical efficacy. Among them, synthetic hydroxyapatite (HAp, Ca10(PO4)6(OH)2) is the most promising because of its biocompatibility, bioactivity, and osteoconductivity. Biocompatibility represents the primary concern for any material to be used as a substitute for natural tissue. Hydroxyapatite particles interact with numerous cellular systems in vivo, and some of these interactions may lead to cell damage and to stimulate platelet activation, coagulation and thrombus formation. The aim of this work was to examine the hemocompatibility of nanocalcium hydroxyapatite substituted with 5% and 12% cobalt (Ca /CoHAp) and hydroxyapatite/polylactidcoglicolid (HAp / PLGA) in relation to pure HAp by testing their hemolytic activities. The results show the discrepancy in hemolytic activity of implanted matherials. The degree of crystallinity of samples had a more dominant influence on hemolysis than the percentage of substituted cobalt. Hemolysis ratios of the nanocalcium hydroxyapatite substituted with cobalt samples were below 3%, indicating good blood compatibility and that they are promising for medical application

Antioxidative responses to seasonal changes and chemiluminescence assay of Astragalus onobrychis leaves extract

The aim of this study was to research the seasonal changes of antioxidant enzyme activity and total antioxidant capacity in leaves of Astragalus onobrychis L. subsp. chlorocarpus (Griseb.) S. Kozuharov et D.K. Pavlova. Leaves of A. onobrychis were collected during the different stages of growth and analyzed for antioxidant enzyme activity: superoxide dismutase, catalase, guaiacol peroxidase, glutathione peroxidase. Quantities of malonyldialdehyde, superoxide radicals, and hydroxyl radicals were measured as well as the content of soluble proteins. Furthermore, total antioxidant capacity was determined by the inhibition of chemiluminescence activity of blood phagocytes by leaf extracts. Stages of vegetation significantly affected the accumulation of superoxide radicals, but there were no significant differences in hydroxyl radical quantity and lipid peroxidation levels during vegetation. Soluble proteins vary greatly between different stages of growth. Seasonal changes were found to have an effect on enzymatic activities. During the spring season, guaiacol peroxidase showed the highest levels. Catalase and glutathione peroxidase increased their activities in summer, while, during the autumn season, superoxide dismutase showed maximum activity. On the basis of chemiluminescence assay, it can be concluded that leaf extract of A. onobrychis possesses a significant antioxidant capacity thus protecting plants during environmental stress

Paramagnetic nanoparticles in the regeneration of the reduced alveolar bone density

One of the trends in the treatment of reduced bone density is in oral implantology through the use of new biomaterials with paramagnetic properties. In this in vivo study the effect of Ca /Co-HAp nanoparticles (calcium/cobalt-hydroxiapatite) in the regeneration of the reduced alveolar bone density in experimental animals was examined by analyzing both the biochemical and histochemical markers and through analysis of alveolar bone density. The research was carried out on female Westar rats, aged 6-8 weeks, whom have been implanted nanobiomaterial in reduced alveolar bone density. Good results in regeneration of reduced bone density were achieved in six weeks after implantation of the nanoparticles with paramagnetic properties. Biochemical markers of osteogenesis showed statistically significant rise. Histological analysis revealed high level reparatory skills of the biocomposite implanted in the bone defect, while X-ray analyses evidenced rise of bone density. Implantation of Ca/Co-Hap enables rapid new formation, thus becoming the material of choice for accelerated reduced bone density regeneration