Effect of Na2O and ZnO on the microstructure and properties of laser cladding derived CaO-SiO2 ceramic coatings on titanium alloys.

To improve the bioactivity of titanium alloy (Ti-6Al-4V), CaO-SiO2 coatings on titanium alloys were fabricated using laser cladding method. The effect of Na2O and ZnO on the microstructure and properties of the prepared coatings was discussed. The microstructure of the CaO-SiO2 coatings consists of cellular grains and cellular dendrites. The mutual diffusion of elements occurs between the coating and substrate. The base CaO-SiO2 coating is composed of different phases including CaTiO3, α-Ca2(SiO4), SiO2, TiO2 and CaO. The formation of CaTiO3 in the ceramic layer was analyzed through thermodynamics. Na2O has little influence on the microstructure, average hardness and wear resistance. When ZnO is added to the precursor, the microstructure turns to cell dendrite, and ZnO and Zn2SiO4 appear in the corresponding coating. The addition of ZnO reduces the average hardness and wear resistance of the ceramic layer. The in vitro soaking in SBF shows that the laser cladding coating has the ability to form an apatite layer.

Interleukin-1ß exacerbates the catabolic effects of human nucleus pulposus cells through activation of the Nuclear Factor kappa B signaling pathway under hypoxic conditions.

OBJECTIVE: To determine the regulatory role of interleukin 1 beta (IL-1ß) in the Nuclear Factor kappa B (NF-κB) -mediated catabolic effects of the nucleus pulposus cells in human intervertebral disc degeneration under hypoxic conditions. PATIENTS AND METHODS: Human nucleus pulposus cells were cultured and exposed to IL-1ß under hypoxic or normoxic environments, with or without NF-κB inhibition. The cell growth was determined using cell counting kit-8; gene and protein expressions were analyzed by Real-time polymerase chain reaction and Western blotting, respectively. RESULTS: Co-treatment with IL-1ß and hypoxia decreased cell viability in human nucleus pulposus cells. There was a positive effect of IL-1ß on human nucleus pulposus cells under hypoxia, which was through the up-regulation of matrix metalloproteinase-3 (MMP-3), MMP-13, a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)-4, and ADAMTS-5. IL-1ß-induced expressions of MMP-3, MMP-9, ADAMTS-4, and ADAMTS-5 under hypoxia were accompanied by increased activation of NF-κB. Inhibition of NF-κBp65 by small interfering RNA or specific inhibitor BAY11-7082 blocked IL-1ß-dependent gene upregulation of MMP-3, MMP-13, ADAMTS-4, and ADAMTS-5 in a hypoxic environment. The gene expression of aggrecan was decreased by IL-1ß under hypoxic conditions, which was reversed by either BAY11-7082 or NF-κBp65 knockdown. CONCLUSIONS: IL-1ß and hypoxia synergetically contributed to the catabolic effects of the nucleus pulposus cells by upregulating the expression of MMP-3, MMP-13, ADAMTS-4 and ADAMTS-5 through the activation of NF-κB signaling pathway, indicating that the NF-κB signaling pathway is a key mediator of intervertebral disc degeneration.

[Gene expression profiles of long non-coding RNAs in human degenerated intervertebral disc tissue].

Objective: To investigate the gene expression profiles of long non-coding RNAs (lncRNA)in human degenerated intervertebral disc degeneration (IDD). Methods: An lncRNA-mRNA microarray analysis of human nucleus pulposus (NP) was employed. Bioinformatics prediction was also applied to delineate the functional roles of the differentially expressed lncRNAs. Several lncRNAs and mRNAs were chosen for quantitative real-time PCR (qRT-PCR) validation. Results: A total of 1 570 lncRNAs expressed in degenerate group compared with the nondegenerate group. Of these, the expression level of 428 lncRNAs was upregulated >2-fold compared with nondegenerate group while that of 584 was downregulated. Bioinformatics analysis (GO and pathway analyses) revealed that some classical pathways participating in extracellular matrix (ECM) and cell apoptosis were aberrantly expressed in the intervertebral disc (P<0.05). Enhancer-like lncRNAs and their nearby coding genes were analyzed. Three lncRNAs were identified as potential enhancers. Several lncRNAs were validated in the intervertebral disc using RT-qPCR. Conclusion: The lncRNAs express differentially in the intervertebral disc. LncRNAs may therefore be novel candidate biomarkers and potential targets for intervertebral disc degeneration therapy in the future.

[High mechanical stretch stress promotes degeneration of the human nucleus pulposus cells through NF-κb signaling pathway].

Objective: To investigate the effect of high mechanical stretch stress(HMS)on human nucleus pulposus cells and its regulatory mechanism. Methods: The non-degenerated nucleus pulposus tissue (Pfirrmann

[Clinical effects of Dynesys system and transfacet decompression through Wiltse approach in the treatment of lumbar degenerative diseases].

Objective: To investigate the early clinical effects of Dynesys system and transfacet decompression by Wiltse approach in the treatment of lumbar degenerative diseases. Methods: From January 2010 to December 2013, 48 patients suffering from lumbar degenerative diseases were treated with Dynesys system in addition to transfacet decompression through Wiltse approach.There were 28 males and 20 females with age of (51.8±6.8). The preoperative diagnosis included lumbar spinal stenosis(10 cases); lumber intervertebral disc herniation (38 cases). There were 23 cases in L4/5, 16 cases in L5/S1 and 9 cases in both of L4/5 and L5/S1.Posterolateral fixation with Dynesys pedicle screw through Wiltse approach.Unilateral resection of the inferior articular facet of the superior vertebra and the superior articular facet of the inferior vertebra.Decompression of the vertebral canal until the never root was decompressed satisfactorily.In the end, Dynesys was performed according to normal procedure.VAS, ODI evaluating standards were applied to evaluate the therapeutic effect.The intervertebral space and ROM of the lumbar were observed by X ray. Results: All patients underwent surgery safely without severe complications occurred.The average following up time was 33.5 (24-60) months.Compared with preoperative parameters (7.7±1.3, 70.8±13.5), the scores of VAS and ODI decreased significantly after surgery (2.3±1.5, 23.6±12.2) and at the final follow-up (2.2±1.4, 20.0±9.8) (P<0.05). There were significant difference in the height of intervertebral space and ROM at the stabilized segment (P<0.05), but no significant changes were seen at the adjacent segments (P>0.05). X-ray scan showed neither instability or internal fixation loosen, breakage or distortion in follow-up. Conclusion: Dynesys system in addition to transfacet decompression through Wiltse approach is a therapy option for mild lumbar degenerative disease.This method can retention the structure of lumbar posterior complex and the activity of the fixed segment, reduce the risk of low back pain together with nerve root decompressed.The early clinical results are satisfactory.

Elevated plasma interleukin-37 levels in systemic lupus erythematosus patients.

This study aims to evaluate the plasma interleukin (IL)-37 levels in systemic lupus erythematosus (SLE) patients, as well as its association with major clinical and laboratory features. Ninety consecutively selected SLE patients and 78 community-based healthy controls were recruited. Plasma IL-37 levels were detected by enzyme-linked immunosorbent assay (ELISA). The major clinical and laboratory data of SLE patients were also recorded. The results showed that IL-37 level was significantly higher in the plasma of patients with SLE compared with controls (p = 0.028). The correlation of plasma IL-37 levels with major clinical and laboratory data of SLE patients was also analyzed, and the results showed that anti-Sm and anti-RNP were negatively associated with plasma IL-37 levels of SLE patients, while C3 was positively associated with plasma IL-37 levels of SLE patients. No significant associations of IL-37 with other clinical and laboratory parameters were observed (all p > 0.05). In conclusion, elevated plasma IL-37 level and its associations with anti-Sm, anti-RNP and C3 in SLE patients suggest that IL-37 may be implicated in this disease.

Effect of CeO2 and Y2O3 on microstructure, bioactivity and degradability of laser cladding CaO-SiO2 coating on titanium alloy.

To solve the lack of strength of bulk biomaterials for load-bearing applications and improve the bioactivity of titanium alloy (Ti-6Al-4V), CaO-SiO2 coatings on titanium alloy were fabricated by laser cladding technique. The effect of CeO2 and Y2O3 on microstructure and properties of laser cladding coating was analyzed. The cross-section microstructure of ceramic layer from top to bottom gradually changes from cellular-dendrite structure to compact cellular crystal. The addition of CeO2 or Y2O3 refines the microstructure of the ceramic layer in the upper and middle regions. The refining effect on the grain is related to the kinds of additives and their content. The coating is mainly composed of CaTiO3, CaO, α-Ca2(SiO4), SiO2 and TiO2. Y2O3 inhibits the formation of CaO. After soaking in simulated body fluid (SBF), the calcium phosphate layer is formed on the coating surface, indicating the coating has bioactivity. After soaking in Tris-HCl solution, the samples doped with CeO2 or Y2O3 present a lower weight loss, indicating the addition of CeO2 or Y2O3 improves the degradability of laser cladding sample.

Effect of ZrO(2) additions on the crystallization, mechanical and biological properties of MgO-CaO-SiO(2)-P(2)O(5)-CaF(2) bioactive glass-ceramics.

A series of ZrO(2) doped MgO-CaO-SiO(2)-P(2)O(5)-CaF(2) bioactive glass-ceramics were obtained by sintering method. The crystallization behavior, phase composition, morphology and structure of glass-ceramics were characterized. The bending strength, elastic modulus, fracture toughness, micro-hardness and thermal expansion coefficient (TEC) of glass-ceramics were investigated. The in vitro bioactivity and cytotoxicity tests were used to evaluate the bioactivity and biocompatibility of glass-ceramics. The sedimentation mechanism and growth process of apatites on sample surface were discussed. The results showed that the mainly crystalline phases of glass-ceramics were Ca(5)(PO4)3F (fluorapatite) and ß-CaSiO(3). (ß-wollastonite). m-ZrO(2) (monoclinic zirconia) declined the crystallization temperatures of glasses. t-ZrO(2) (tetragonal zirconia) increased the crystallization temperature of Ca(5)(PO4)(3)F and declined the crystallization temperature of ß-CaSiO(3). t-ZrO(2) greatly increased the fracture toughness, bending strength and micro-hardness of glass-ceramics. The nanometer apatites were induced on the surface of glass-ceramic after soaking 28 days in SBF (simulated body fluid), indicating the glass-ceramic has good bioactivity. The in vitro cytotoxicity test demonstrated the glass-ceramic has no toxicity to cell.

Influence of fluoride additions on biological and mechanical properties of Na2O-CaO-SiO2-P2O5 glass-ceramics.

Two series of Na2O-CaO-SiO2-P2O5 glass-ceramics doped with NH4HF2 (G-NH4HF2) or CaF2 (G-CaF2) have been prepared by sol-gel method. The glass-ceramic phase composition and morphology were characterized by X-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS). The mechanical properties and thermal expansion coefficient were measured by a microhardness tester, an electronic tensile machine and a thermal expansion coefficient tester. The structure difference between these two glass-ceramics was investigated by Fourier transform infrared spectroscopy (FTIR), and the in vitro bioactivity of the glass-ceramics was determined by in vitro simulated body fluid (SBF) immersion test. The hemolysis test, in vitro cytotoxicity test, systemic toxicity test and the implanted experiment in animals were used to evaluate the biocompatibility of the glass-ceramics. The mechanical properties of sample G-NH4HF2 are lower than that of sample G-CaF2, and the bioactivity of sample G-NH4HF2 is better than that of sample G-CaF2. The thermal expansion coefficients of these two glass-ceramics are all closer to that of Ti6Al4V. After 7 days of SBF immersion, apatites were induced on glass-ceramic surface, indicating that the glass-ceramics have bioactivity. The hemolysis test, in vitro cytotoxicity test and systemic toxicity test demonstrate that the glass-ceramics do not cause hemolysis reaction, and have no toxicity to cell and living animal. The implanted experiment in animals shows that bone tissue can form a good osseointegration with the implant after implantation for two months, indicating that the glass-ceramics are safe to serve as implants.

Improvement of corrosion and biological properties of microarc oxidized coatings on Mg-Zn-Zr alloy by optimizing negative power density parameters.

Corrosion and biological properties of microarc oxidized calcium phosphate (CaP) coatings on Mg-Zn-Zr alloy were improved by optimizing negative power density parameters. Scanning electron microscope (SEM) and X-ray diffractometer (XRD) were employed to characterize the coating morphology and phase composition. The in vitro cytotoxicity and systemic toxicity tests were carried out to evaluate the coating biocompatibility. The degradability and bioactivity of the coatings were determined by in vitro simulated body fluid (SBF) immersion test. The coating microstructure, thickness and growth rate can be influenced by negative power density through changing direction of ions movements, rate of ions exchanges and affecting formation of plasma. The CaP coatings reduced the substrate degradation rate. Calcium phosphates, such as hydroxyapatite (Ca10(PO4)6(OH)2, HA) and calcium pyrophosphate (Ca2P2O7, CPP), etc., were induced after 30 days SBF immersion, indicating that the coatings have bioactivity. The CaP coatings have no toxicity to cell and living mice, indicating that the coatings are safe to serve as implants.

Effect of various additives on microstructure, mechanical properties, and in vitro bioactivity of sodium oxide-calcium oxide-silica-phosphorus pentoxide glass-ceramics.

The partial substitution of MgO, TiO2, or CaF2 for CaO in the Na2O-CaO-SiO2-P2O5 (45S5) system was conducted by the sol-gel method and a comparative study on structural, mechanical properties, and bioactivity of the glasses was reported. Based on thermogravimetric and differential thermal analysis, the gels were sintered with a suitable heat treatment procedure. The glass-ceramic properties were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and so on, and the bioactivity of the glass-ceramic was evaluated by in vitro assays in simulated body fluid (SBF). Results indicate that with the partial substitution of MgO, TiO2, CaF2 for CaO in glass composition, the mechanical properties of the glass-ceramics have been significantly improved. Furthermore, CaF2 promotes glass crystallization and the crystallization does not inhibit the glass-ceramic bioactivity. All samples possess bioactivity; however, the bioactivity of these glass-ceramics is quite different. Compared with 45S5, the introduction of MgO decreases the ability of apatite induction. The addition of TiO2 does not significantly improve the bioactivity, and the replacement of CaO by CaF2 shows a higher bioactivity.

Effects of phosphates on microstructure and bioactivity of micro-arc oxidized calcium phosphate coatings on Mg-Zn-Zr magnesium alloy.

Calcium phosphate (CaP) coatings were prepared on Mg-Zn-Zr magnesium alloy by micro-arc oxidation (MAO) in electrolyte containing calcium acetate monohydrate (CH3COO)2Ca·H2O) and different phosphates (i.e. disodium hydrogen phosphate dodecahydrate (Na2HPO4·12H2O), sodium phosphate (Na3PO4·H2O) and sodium hexametaphosphate((NaPO3)6)). Scanning electron microscope (SEM), energy-dispersive X-ray spectrometry (EDS) and X-ray diffractometer (XRD) were employed to characterize the microstructure, elemental distribution and phase composition of the CaP coatings. Simulated body fluid (SBF) immersion test was used to evaluate the coating bioactivity and degradability. Systemic toxicity test was used to evaluate the coating biocompatibility. Fluoride ion selective electrode (ISE) was used to measure F(-) ions concentration during 30 days SBF immersion. The CaP coatings effectively reduced the corrosion rate and the surfaces of CaP coatings were covered by a new layer formed of numerous needle-like and scale-like apatites. The formation of these calcium phosphate apatites indicates that the coatings have excellent bioactivity. The coatings formed in (NaPO3)6-containging electrolyte exhibit thicker thickness, higher adhesive strength, slower degradation rate, better apatite-inducing ability and biocompatibility.

Effects of broccoli stem and leaf meal on broiler performance, skin pigmentation, antioxidant function, and meat quality.

Three hundred sixty 1-d-old Ross 308 male broilers were used to study the effects of broccoli stem and leaf meal (BSLM) on growth performance, skin pigmentation, antioxidant function, and meat quality. The chicks were fed 4 diets containing different levels (0, 4.0, 8.0, and 12.0%) of BSLM as partial replacement for corn and soybean meal for a period of 42 d. The results showed that dietary supplementation of BSLM had no effect (P > 0.05) on growth performance. As compared with control, dietary 4%, 8%, and 12% BSLM increased (P < 0.05) b value (yellowness) both in shank and breast skin, increased (P < 0.05) the concentrations of xanthophylls in abdominal fat and breast skin, improved (P < 0.05) total antioxidant capability, lowered malondialdehyde concentration, and decreased drip loss percentage of breast muscle. Dietary 8% and 12% BSLM decreased (P < 0.05) shank L values (lightness), increased (P < 0.05) shank a value (redness), and increased (P < 0.05) the activities of superoxide dismutase and catalase of breast muscle as compared with control. The results indicated that dietary supplementation of BSLM in broiler chickens improved the poultry products quality with the more skin pigmentation and the less drip loss percentage of breast meat. The more skin pigmentation mainly related to the high amount of xanthophylls in BSLM. The decreased meat drip loss fed BSLM may be caused by the antioxidative function of BSLM.

Microstructure and biological properties of micro-arc oxidation coatings on ZK60 magnesium alloy.

Ceramic coatings were prepared on ZK60 magnesium alloy in electrolyte with different concentration ratio of calcium and phosphorus (Ca/P) by micro-arc oxidation (MAO) technique at constant voltage. The microstructure, phase composition, elemental distribution, corrosion resistance, and adhesion of the coatings were investigated by scanning electron microscope (SEM), X-ray diffractometer (XRD), energy-dispersive X-ray spectrometry (EDS), electrochemical workstation, and scratch spectrometer, respectively. The coating biocompatibility was evaluated by in vitro cytotoxicity tests and systemic toxicity tests, and the bioactivity and degradability were evaluated by simulation body fluid (SBF) immersion tests. SEM shows that pores with different shapes distribute all over the coating surface. The adhesion and thickness of the coatings increases with increasing Ca/P ratio of electrolyte. The in vitro cytotoxicity tests and systemic toxicity texts demonstrate that the coatings have no toxicity to cell and living animal, which show that the coatings have excellent biocompatibility. XRD analysis shows that bioactive calciumphosphate (CaP) phases such as hydroxyapatite (HA, Ca(10)(PO(4))(6)(OH)(2)) and calcium pyrophosphate (CPP, Ca(2)P(2)O(7)) are induced in the immersed coatings, indicating that the MAO coatings have excellent bioactivity.

Effect of magnesia on the degradability and bioactivity of sol-gel derived SiO2-CaO-MgO-P2O5 system glasses.

Mesoporous 58SiO(2)-(38-x)CaO-xMgO-4P(2)O(5) glasses (where x=0, 5, 10 and 20 mol%) have been prepared by the sol-gel synthesis route. The effects of the substitution of MgO for CaO on glass degradation and bioactivity were studied in tris-(hydroxymethyl)-aminomethane and hydrochloric acid buffer solution (Tris-HCl) and simulated body fluid (SBF), respectively. It is observed that the synthesized glasses with various MgO contents possess the similar textural properties. The studies of in vitro degradability and bioactivity show that the rate of glass degradation gradually decreases with the increase of MgO and the formation of apatite layer on glass surface is retarded. The influences of the composition upon glass properties are explained in terms of their internal structures.

In situ synthesis of hydroxyapatite coating by laser cladding.

HA bioceramic coatings were synthesized on titanium substrate by laser cladding using cheap calcium carbonate and calcium hydrogen phosphate. The thermodynamic condition for synthesizing HA was calculated by software Matlab 5.0, the microstructure and phase analysis of laser clad HA bioceramic coatings were studied by electron probe microanalyser (EPMA), X-ray diffractometer (XRD) and transmission electron microscopy (TEM). The theoretical results show that the Gibbs free enthalpy for the synthesis of HA phase is satisfied, and the presence of HA phase in the clad coatings was then further verified by XRD and the selected area diffraction patterns. When the laser power is 600W and the scanning speed is 3.5mm/s, the compact HA bioceramic coatings were obtained, which have cellular dendritic structure and consist of the phases of HA, alpha-Ca(2)P(2)O(7), CaO and CaTiO(3).

Culture of smooth muscle cells from guinea pig mesenteric lymphatic vessels.

The in vitro culture of lymphatic smooth muscle cells (SMCs) is a crucial step in studying their function and involvement in disease. Yet there is no efficient approach available so far because of the difficulties posed by the small size of most lymphatic vessels. We present a simple yet efficient method for isolating and culturing SMCs of collecting lymphatic vessels from guinea pig mesenteric tissue. In our approach, thin lymphatic vessels were digested twice from adventitia to media to release SMCs, which were then cultured by traditional methods. The lymphatic SMCs we cultured did not exhibit contact inhibition and demonstrated typical SMCs characteristics under light microscope, electron microscope and by immunohistochemical studies. This method is applicable to the culturing of lymphatic SMCs from other organs and provides useful materials for physiological and pathological lymphatic studies.

Photoprotection by tocopherol submicron emulsion against UV-mediated damage in HaCaT cells.

alpha-Tocopherol is a lipophilic vitamin E that shows antioxidative, antiaging and antiphotodamage activity. Nanometer biotechnology is more widely used in the entrainment system of drug carriers and the development for new pharmaceutical preparations. Ultraviolet irradiation to human skin in the long term can result in photoaging and photocarcinogenesis. The purpose of this study was to observe the biological features of tocopherol submicron emulsion (vitE SME) and to clarify the roles of vitE SME on UVB-induced photodamage in HaCaT keratinocytes (KC). VitE SME was prepared by high-pressure homogenization and microemulsion technique. HaCaT KC was incubated in the culture medium supplied with 1/200 and 1/400 of VitE SME prior to different dosages of UVB irradiation. The vitamin E amount in the culture medium was measured by high-performance liquid chromatography (HPLC). Cell growth and cellular viability was detected by MTT assay. The amount of vitamin E remaining in the culture medium significantly decreased during the first 8 h, and less than 10% can be detected by the terminal experiment (24 h). No cytotoxicity effect of tocopherol NM on HaCat KC was observed. In contrast to the control group, the cellular viability of VitE SME-treated group increased 44.22% by 24 h. Compared with irradiated groups without VitE SME, cell proliferation decreased by 17.77% and 40.42% when the HaCaT KC was irradiated with 30 mJ/cm(2) and 90 mJ/cm(2) UVB irradiation, respectively. VitE SME has no toxicity to cell culture system and is characterized by stable release and penetration. Pre-incubation with VitE SME can partly reduce UV-induced cell damage, and the photoprotective efficiency to UVB irradiation also shows time dependence.