Interventional effect of asiaticosdide on rats exposed to silica dust / 中华劳动卫生职业病杂志

Objective: To investigate the effect of asiaticoside for fibrosis in lung tissues of rats exposed to silica and to explore its possible mechanism. Methods: 144 SD male rats were randomly divided into control group, model group, positive drug control group, asiaticoside high-dose group, medium-dose group and low-dose group, each group included 24 rats. Rats in the control group were perfused with 1.0 ml of normal saline, and the other groups were given 1.0 ml 50 mg/ml SiO(2) suspension. Gavage of herbal was given from the next day after model establishment, once a day. Rats in the positive drug control group were administration with 30 mg/kg tetrandrine and rats in the low-dose group, medium-dose group and high-dose group were given 20 mg/kg, 40 mg/kg and 60 mg/kg asiaticoside for fibrosis respectively. Rats in the control group and the model group were given 0.9% normal saline. The rats were sacrificed in on the 14th, 28th and 56th day after intragastric administration and collect the lung tissues to detect the content of hydroxyproline, TGF-β(1) and IL-18, observe the pathological changes of the lung tissues by HE and Masson staining and determine the expressions of Col-I, a-SMA, TGF-β in lung tissues by Western Blot. Results: On the 14th day, 28th day and 56th day after model establishment, the lung tissues of rats in the model group showed obvious inflammatory response and accumulation of collagen fibers, and the degree of inflammation and fibrosis increased with time. The intervention of asiaticoside could effectively inhibit the pathological changes of lung tissues. The contents of hydroxyproline, IL-18 and TGF-β1 in lung tissues of model group were higher than those in the control group (P<0.05) , while the level of hydroxyproline, IL-18 and TGF-β1 in asiaticoside groups were significantly decreased, and the difference was statistically signicant (P<0.05) . Compared with the control group, the expression levels of Col-I, TGF-β1and α-SMA in lung tissue of model group were increased (P<0.05) , while the expression level of Col-I, TGF-β1 and α-SMA were decreased after the intervention of asiaticoside, and the difference was statistically signicant (P<0.05) . Conclusion: Asiaticoside can inhibit the increase of Col-I, TGF-β1 and α-SMA content in the SiO(2)-induced lung tissues of rats, reduce the release of TGF-β1 and IL-18 inflammatory factors in lung tissue, and then inhibit the synthesis and deposition of extracellular matrix in rat lung tissue, and improve silicosis fibrosis.

Mechanism of Dahuang Zhechongwan in Inhibiting Silicosis in Mice via p38 MAPK/NF-κB/TGF-β1 Pathway / 中国实验方剂学杂志

Objective:To explore the effects and mechanism of Chinese classical prescription Dahuang Zhechongwan on silicosis in mice. Method:Thirty-six male Kunming mice of SPF grade were randomized into the normal control group， model control group， tetrandrine （Tet， 0.039 mg·kg^-1） group， as well as high- （1.560 g·kg^-1）， medium- （0.780 g·kg^-1）， and low-dose （0.390 g·kg^-1） Dahuang Zhechongwan groups， with six mice in each group. Mice in all groups except for the normal control group underwent static inhalation of silica （SiO₂） dust for 40 consecutive days to induce fibrosis. After 28 days of intervention with corresponding drugs， the mice were sacrificed to collect the serum and lung tissues， with the former used for detecting tumor necrosis factor-<italic>α</italic> （TNF-<italic>α</italic>）， interleukin-1<italic>β </italic>（IL-1<italic>β</italic>）， IL-6， and hydroxyproline （HYP） levels by enzyme-linked immunosorbent assay （ELISA） and the latter for observing the pathological changes. Meanwhile， the protein and mRNA expression levels of p38 mitogen-activated protein kinase （p38 MAPK）， nuclear transcription factor-<italic>κ</italic>B （NF-<italic>κ</italic>B）， transforming growth factor-<italic>β</italic>₁ （TGF-<italic>β</italic>₁）， <italic>α</italic>-smooth muscle actin （<italic>α</italic>-SMA）， Smad2， Smad3， and Smad7 in the lung tissues were determined by Western blot and real-time polymerase chain reaction （Real-time PCR）. Result:Compared with the normal group， the contents of TNF-<italic>α</italic>， IL-1<italic>β</italic>， IL-6 and HYP in the model group were significantly increased， the difference was statistically significant（<italic>P</italic><0.05，<italic>P</italic><0.01）； compared with the model group， the high-dose group of Dahuang Zhechongwan could significantly reduce the contents of TNF-<italic>α</italic>， IL-6 and HYP in the serum of mice（<italic>P</italic><0.05， <italic>P</italic><0.01）， indicating that Dahuang Zhechongwan could reduce the lung inflammation of silicosis mice. At the same time， compared with the normal group， the protein and mRNA expression levels of p38 MAPK， NF-<italic>κ</italic>B p65， TGF-<italic>β</italic>₁， <italic>α</italic>-SMA， Smad2 and Smad3 in the model group were significantly increased（<italic>P</italic><0.05，<italic>P</italic><0.01）， while the protein and mRNA expression levels of Smad7 were significantly decreased（<italic>P</italic><0.01）； compared with the model group， the protein and mRNA expression levels of p38 MAPK， NF-<italic>κ</italic>B p65， TGF-<italic>β</italic>₁， <italic>α</italic>-SMA， Smad2 and Smad3 in the high-dose Dahuang Zhechongwan group were significantly increased the protein and mRNA expression levels were significantly decreased（<italic>P</italic><0.05，<italic>P</italic><0.01）， while Smad7 protein and mRNA expression levels were significantly increased（<italic>P</italic><0.05，<italic>P</italic><0.01）. Conclusion:Dahuang Zhechongwan ameliorates the alveolar inflammation， extracellular matrix （ECM） deposition， and fibrosis in mice with silicosis possibly by regulating the p38 MAPK/NF-<italic>κ</italic>B/TGF-<italic>β</italic>₁ pathway.

Effect of SiO2 and Al2 O3 nanoparticles on wear resistance of PMMA acrylic denture teeth / Efeito das nanopartículas de SiO2 e Al2 O3 na resistência ao desgaste de dentes em acrílico PMMA para prótese

Objetivo: Este estudo teve como objetivo avaliar a resistência ao desgaste de dentes em acrílico para próteses contendo nanopartículas de dióxido de silício (nano-SiO2 ) e dióxido de alumínio (nanoAl2 O3 ). Material e Métodos: O material em polimetilmetacrilato (PMMA) foi utilizado para fabricar 84 amostras (n=10) contendo nano-SiO2 e nano-Al2 O3 nas concentrações 0,1% em peso, 0,3% em peso e 0,5% em peso de pó acrílico. Uma máquina de teste de desgaste de dois corpos e um microscópio digital foram usados para medir as mudanças na perda de peso e rugosidade da superfície, respectivamente. Testes de ANOVA a um fator e testes de comparações múltiplas de Tukey foram utilizados para análise dos dados (α = 0,05). Resultados: O material modificado com nano-SiO2 demonstrou um aumento significativo na perda de peso em comparação com o material acrílico artificial convencional (p ˂ 0,05) enquanto o material modificado com nano-Al2 O3 demonstrou aumento não significativo na perda de peso, exceto no subgrupo 0,5% (p < 0,05). Não há diferenças significativas em relação à alteração da rugosidade após a simulação de desgaste entre todos os grupos testados (p > 0,05). Conclusão: As nanopartículas de nano-Al2 O3 exibem menos efeito negativo que o nanoSiO2 , podendo ser usado com cautela, se necessário. (AU)

Objective: This study aimed to evaluate the wear resistance of acrylic denture teeth containing silicon dioxide (nano-SiO2 ) and aluminum dioxide (nano-Al2 O3 ) nanoparticles. Material and Methods: Poly methyl methacrylate (PMMA) denture tooth material was used to denture tooth material was used to fabricate 84 specimens (n=10) containing nano-SiO2 and nano-Al2 O3 in concentrations 0.1wt%, 0.3wt%, and 0.5wt% of acrylic powder. A two-body wear testing machine and digital microscope were used to measure the changes in weight loss and surface roughness respectively. One-way ANOVA and pair-wise Tukey's post-hoc tests were used for data analysis (α = 0.05). Results: Nano-SiO2 modified teeth material demonstrated a significant increase in weight loss in comparison conventional artificial acrylic teeth material (p ˂ 0.05) while nanoAl2 O3 modified teeth material demonstrated non-significant increase in weight loss except for 0.5% subgroup (p ˂ 0.05). There is no significant differences regarding roughness change after wear simulation among all tested groups (p > 0.05). Conclusion: Nano-Al2 O3 nanoparticles exhibit less negative effect than nano-SiO2 so; it could be used with caution if necessary. (AU)

Trace determination and characterization of ginsenosides in rat plasma through magnetic dispersive solid-phase extraction based on core-shell polydopamine-coated magnetic nanoparticles / 药物分析学报

Enrichment of trace bioactive constituents and metabolites from complex biological samples is chal-lenging. This study presented a one-pot synthesis of magnetic polydopamine nanoparticles (Fe3O4@-SiO2@PDA NPs) with multiple recognition sites for the magnetic dispersive solid-phase extraction (MDSPE) of ginsenosides from rat plasma treated with white ginseng. The extracted ginsenosides were characterized by combining an ultra-high-performance liquid chromatography coupled to a high-resolution mass spectrometry with supplemental UNIFI libraries. Response surface methodology was statistically used to optimize the extraction procedure of the ginsenosides. The reusability of Fe3O4@-SiO2@PDA NPs was also examined and the results showed that the recovery rate exceeded 80％ after recycling 6 times. Furthermore, the proposed method showed greater enrichment efficiency and could rapidly determine and characterize 23 ginsenoside prototypes and metabolites from plasma. In com-parison, conventional methanol method can only detect 8 ginsenosides from the same plasma samples. The proposed approach can provide methodological reference for the trace determination and charac-terization of different bioactive ingredients and metabolites of traditional Chinese medicines and food.

Study on preparation, characterization, and transformation of icariin of immobilized snailase on nano-SiO2 / 中草药

Objective: To prepare the immobilized snailase on cross-linked nano-SiO2, characterize its physicochemical properties, and investigate the optimal conditions of hydrolyzing icariin to baohuoside Ⅰ and enzymatic properties. Methods: The snailase was immobilized on the glutaraldehyde cross-linked nano-SiO2 by covalent coupling method. The immobilization conditions were optimized using the relative enzyme activity as the test index. Transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR), and elemental analysis methods were used to characterize the physicochemical properties of immobilized snailase. Using icariin as the substrate and free enzyme as the control, the optimal enzyme conditions, enzymatic kinetic parameters, recyclability, and thermal stability of the immobilized snailase were also investigated. Results: The optimal mass ratio of enzyme to carrier was 1:3 and the optimal immobilization time was 6 h for the preparation of the immobilized snailase. The optimum hydrolysis conditions of the immobilized snailase were as follows: pH 5.0, conversion temperature 60 ℃, mass ratio of enzyme to substrate 1:2, and transformation time 12 h. The Vmax and Km of the immobilized snailase was 0.43 μg/min and 0.78 mmol/L, respectively. After repeated use for 5 times, the residual relative enzyme activity of the immobilized snailase maintained above 70%. Conclusion: The immobilized snailase on cross-linked nano-SiO2 has high mechanical strength, strong stability, and good reusability. It can hydrolyze the icariin to the baohuoside Ⅰ with a better activity. The hydrolysis process was simple, easy, and suitable for industrial production.

Comparison study on the differential expression of miRNAs in rat pulmonary fibrosis induced by nanosized SiO2 and microsized SiO2 / 中华劳动卫生职业病杂志

Objective@#To explore the correlation between expression level of miRNAs and pulmonary fibrosis on the basis of comparison the differential expression of miRNAs in rat pulmonary fibrosis induced by nano SiO2 and micron SiO2.@*Methods@#Thirty-six healthy male SD rats weighting 180-220 g were randomly divided into 3 groups. They were instilled intratracheally with 1 ml suspension of saline, 25 mg/ml nanosized SiO2 and microsized SiO2 particles and sacrificed at 60 d and 90 d postexposure from each group with six rats. The change of pathological morphology and ultrastructure of lung were observed by optical and transmission electron microscopy. The differentially expressed microRNAs in lung tissue of the rats after instilled intrachcally nanosized SiO2 and microsized SiO2 particles at 60 d and 90 d were determined by Illumina HiSeq 2 000 sequencing technique. Target prediction for miRNAs was conducted by databases of Target-scan. Function-significant enrichment analysis and signal pathway analysis for predicted target genes were respectively conducted by the GO and the KEGG, then target genes related to pulmonary fibrosis were screened out.@*Results@#Light microscope examination showed that wide bronchi, vessels, interlobular septa and slight fibrous connective tissue proliferation at 60 d and 90 d postexposure in 25 mg/ml nanosized SiO2 group. A few fused nodules at 30 d postexposure, a lot of fused nodules at 60 d postexposure, fibrous cell nodules and compensatory emphysema around alveolar at 90 d postexposure in 25 mg/mL microsized SiO2 group were observed. Electron microscopy demonstrated swelling and vacuolar degeneration of osmiophilic lamellar bodies in type Ⅱ alveolar epithelial cells, collagen fiber and elastic fiber hyperplasia in pulmonary interstitial at 60 d, 90 d postexposure in 25 mg/ml nanosized SiO2 group. Increased and vacuoloid changed osmiophilic lamellar bodies in type Ⅱ alveolar epithelial cells, collagen fiber and elastic fiber hyperplasia in the interstitial at 60 d, 90 d postexposure in 25 mg/ml microsized SiO2 group were observed. Comparing to saline control group, the number of miRNA up-regulated expression was 50, 70, and down-regulated expression was 22 and 24 at 60 d, 90 d postexposure in 25 mg/ml nanosized SiO2 group respectively. There were 91,70 miRNAs up-regulated expression and 34,78 miRNAs down-regulated expression at 60 d, 90 d postexposure in 25 mg/ml microscale SiO2 group. The common miRNA of differential up-regulated expression are miRNA-18a and miRNA-702-3p, down-regulated expression are miRNA-541, miRNA-127 and miRNA-379 both in nanosized SiO2 and microscale SiO2 group. The target genes related to pulmonary fibrosis were CTGF, IGF, BMP7, FGF7, TGF-β RIII, IGF1R and TGF-β1 respectively. Their biologic functions are to regulate signal pathway of TGF-β, MAPK and Wnt, and activation of fibroblast.@*Conclusion@#These findings suggested that same dose of nanosized SiO2 particles could cause mainly characterized by pulmonary interstitial fibrosis differing from silicotic nodule caused by microsized SiO2. miRNA-18a, miRNA-702-3p, miRNA-541, miRNA-127 and miRNA-379 may play a role in the process of pulmonary fibrosis in nanosized SiO2 and microscale SiO2 by regulating its target genes.

Effect of Akt signaling pathway on phosphorylation of RAW264.7 cells induced by SiO_2 / 中国职业医学

OBJECTIVE: To observe the status of protein kinase B(Akt) signaling pathway in Akt phosphorylation induced by free silica(SiO_2) in mouse monocyte macrophage cell RAW264.7, and the role of Akt signaling pathway in early inflammatory response of silicosis. METHODS: i) RAW264.7 cells were routinely cultured and divided into SiO_2 stimulation groups at 5 different time points, and were stimulated for 15, 30, 60, 120 and 240 minutes with SiO_2 suspension with a final concentration of 100 mg/L, and a control group without SiO_2 treatment. At the end of treatment, the cells were collected and the expression of phospho-(Ser/Thr) Akt(p-Akt) was detected by Western blotting to select the optimal time of treatment. ii) RAW264.7 cells were divided into control group(no treatment), SiO_2 exposure group(previous concentration of 100 mg/L SiO_2 suspension) and intervention group(pre-treated with Akt activation inhibitor deguelin for one hour and then treated with 100 mg/L SiO_2 suspension), samples were collected after incubation for 60 minutes. The p-Akt expression and distribution in cells were detected by cellular immunofluorescence assay, the relative expression of p-Akt in cells was detected by Western blotting, and the levels of tumor necrosis factor-α(TNF-α) and transforming growth factor-β1(TGF-β1) in the supernatant of cells were detected by enzyme-linked immunosorbent assay. RESULTS: i) The optimal treatment time of RAW264.7 cells for SiO_2 exposure model was 60 minutes in vitro. ii) The results of cellular immunofluorescence assay showed that Akt phosphorylation was activated in RAW264.7 cells after stimulant with SiO_2, and the fluorescence of p-Akt was enhanced in the SiO_2 exposure group than the control group, and in the intervention group it was relatively weaker than the SiO_2 exposure group. The relative expression of p-Akt as well as the levels of TNF-α and TGF-β1 in the SiO_2 exposure group and the intervention group were higher than that in the control group(P<0.05), and the above three idexes in the intervention group were lower than the SiO_2 exposure group(P<0.05). CONCLUSION: Akt signaling pathway is involved in the process of SiO_2-induced macrophages phosphorylation, and participates in the early inflammatory response of silicosis.

Preparation and characterization of SiO2 solid dispersions of Curcumae longae Rhizoma extract / 中成药

AIM To prepare and characterize SiO2 solid dispersions of Curcumae longae Rhizoma extract.METHODS For the solid dispersions prepared by solvent evaporation method,its ratio of extract to carrier (SiO2) was screened by in vitro dissolution test,and the characterization was achieved by determination of particle size,specific surface area,porosity,micromorphology observation,infrared spectroscopy and X-ray.RESULTS When the ratio of extract to carfer was 1:8,three main components (bisdemethoxycurcumin,demethoxycurcumin and curcumin) in the extract reached the highest accumulative dissolution rates.Compared with physical mixture,the solid dispersions demonstrated lower particle size,specific surface area and porosity.Extract was dispensed in the carrier in an amorphous state.CONCLUSION SiO2 solid dispersions can obviously improve the dissolution rates of the main components in Curcumae longae Rhizoma extract.

Influence of α-Si3N4 and SP1SiO2 fusing conditions and filler ratios in properities of dental resin composites / 吉林大学学报(医学版)

Objective: To detect the optimal fusing temperature, the fusing time and the best filler ratio of α-Si3N4 and SP1SiO2, and to clarify their influence in the properities of dental resin composites. Methods: The α-Si3N4 crystalline were mixed with SP1SiO2 particle at the ratio of5:l (Wt%), and then were sintered under 500°C, 650°C, 800°C, 950°C and 1 100°C at a rise rate of 250 · h-1 and maintained for 10 min, 30 min and 3 h, respectively (used as α-Si3N4-SP1SiO2 groups). SP1SiO2 particle, α-Si3N4 crystalline, mixed and non-fused α-Si3N4 and SP1SiO2 (mixed) groups were set up, and two commercially available resin composites were selected and used as control groups. And they were fully mixed with the resin matrix in 60% (Wt%) after the treatment of cyclohexane solution to make the samples. The flexural strength of specimen was tested and the morphology of section under SEM was analyzed. Then α-Si3N4 was mixed with SP1SiO2 in a ratio of 2; 1. It was fused under the optimal fusing conditions. After the treatment of cyclohexane solution, it was mixed and polymerized with the resin matrix in the proportions of 20%, 40%, 60%, 70% and 75% (Wt%), and two kinds of commercially available resin composites were selected and used as control groups. The flexural strength of specimens was tested and the morphology of section under SEM was analyzed. Results: The maximum flexural strength value in α-Si3N1-SP1SiO2 groups was at 800°C and 30 min (P>0. 05); the flexural strength value was significantly higher than those in SP1SiO2 group, α-Si3N1 crystalline group, mixed group and two control groups (P<0. 05), and the morphology of section SEM was consistent with the mechanical properties. The flexural strengths of resin composites were increased gradually with the increasing of filler ratios of α-Si3N4 and SP1SiO2 fusion from 20% to 60% (P<0. 05); the flexural strength values of resin composites with the proportion of 60%-70% were not increased significantly, the flexural strength values of resin composites with the proportion of 70%-75% were decreased, and the flexural strength values of the resin composites with the proportion of 60% and 70% were significantly higher than those of resin composites with the proportions of 20%, 40%, 75% and control groups; the morphology of section under SEM was consistent with the mechanical properties. Conclusion: The optimum fusing condition for α-Si3N4 and SP1SiO2 is 800°C for 30 min, and the best filler ratio of α-Si3N4 and SP1SiO2 is 70%.

Effects of SiO2 nanoparticles by intratracheal instilation on major organs of mice in vivo / 吉林大学学报(医学版)

Objective:To study the effects of SiO2 nanoparticles on the organs of mice in vivo after intratracheal instillation, and to provide the basis for safety evaluation of SiO2 nanoparticles. Methods:Forty female BALB/c mice aged 6-8 weeks were randomly divided into control group (saline), low dose of SiO2 group (7 mg·kg-1), middle dose of SiO2 group (21 mg·kg-1), and high dose of SiO2 group (35 mg·kg-1).1 and 15 d after five times of non-exposed intratracheal instilation infection (once every 3 d), the mice were sacrificed and the left lungs,the right kidneys, livers, hearts and spleens were collected and embedded in paraffin.The morphology of tissue sections was observed under light microscope after hematoxylin-eosin (HE) staining.The eyeball blood was obtained and the biochemical indicators of liver and kidndy functions were detected.Results:Compared with control group, there were alveolar interval thickening, inflammatory cell infiltration, and a small amount of small arterial thrombosis in the lungs;granulomatous inflammatory cell infiltration and a small amount of focal necrosis of liver cells in the livers;red pulp enlargement, hyperemia, and more visibly scattered megakaryocytes in the spleens in SiO2 nanoparticles groups in a dose-dependent manner, especially in middle and high doses of SiO2 groups.After 15 d of injection, the damages alleviated with the prolongation of time.There was some inflammatory cell infiltration in the kidney tissue of the mice in SiO2 nanoparticle groups.The biochemical indicator detection results showed that alanine aminotransferase(ALT) and aspartate transaminase(AST) levels in SiO2 nanoparticles groups varied, suggesting the liver cell damages were at different degrees;the changes of urea nitrogen(BUN) and creatinine(Cr) levels in SiO2 nanoparticle groups remindered the kidney function alteration, but there were no obvious dose-and time-dependent effects.Conclusion:Intratracheal instillation of SiO2 nanoparticles can influence the major organs of the mice and mainly displays in the inflammation and injuries in the lung, liver, and spleen.

Pulmonary Toxicity in Rats Caused by Exposure to Intratracheal Instillation of SiO2 Nanoparticles / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>The effect of the silica nanoparticles (SNs) on lungs injury in rats was investigated to evaluate the toxicity and possible mechanisms for SNs.</p><p><b>METHODS</b>Male Wistar rats were instilled intratracheally with 1 mL of saline containing 6.25, 12.5, and 25.0 mg of SNs or 25.0 mg of microscale SiO2 particles suspensions for 30 d, were then sacrificed. Histopathological and ultrastructural change in lungs, and chemical components in the urine excretions were investigated by light microscope, TEM and EDS. MDA, NO and hydroxyproline (Hyp) in lung homogenates were quantified by spectrophotometry. Contents of TNF-α, TGF-β1, IL-1β, and MMP-2 in lung tissue were determined by immunohistochemistry staining.</p><p><b>RESULTS</b>There is massive excretion of Si substance in urine. The SNs lead pulmonary lesions of rise in lung/body coefficients, lung inflammation, damaged alveoli, granuloma nodules formation, and collagen metabolized perturbation, and lung tissue damage is milder than those of microscale SiO2 particles. The SNs also cause increase lipid peroxidation and high expression of cytokines.</p><p><b>CONCLUSION</b>The SNs result into pulmonary fibrosis by means of increase lipid peroxidation and high expression of cytokines. Milder effect of the SNs on pulmonary fibrosis comparing to microscale SiO2 particles is contributed to its elimination from urine due to their ultrafine particle size.</p>

Anti-pepsin activity of silicon dioxide nanoparticles / Actividad antipepsina de nanopartículas de dióxido de silicio / Atividade antipepsina de nanopartículas de dióxido de silício

SiO2NPs as an inhibitor of pepsin enzyme for treatment of gastro-esophageal reflux disease (GERD) were investigated. Silicon dioxide nanoparticles (pepsin coated SiO2NPs) are among the safest nanoparticles that can be used inside the human body. The activity of pepsin before and after the addition of certain amounts of the NPs to the reaction mixture was measured spectrophotometrically. Furthermore, these experiments were repeated at different temperatures, different weights of NPs, and different ionic strengths. The kinetic parameters (Km & Vmax) of the pepsin-catalyzed reactions were calculated from the Lineweaver-Burk plots. The results showed that there is a significant reduction of pepsin activity by SiO2NPs (Vmax of free pepsin = 4.82 U and Vmax of the immobilized pepsin = 2.90 U). The results also indicated that the presence of ionic strength causes remarkable reduction of pepsin activity. It can be concluded the best condition for inhibition of pepsin activity is by using a combinationof SiO2NPs and high concentration NaCl at 37 °C.

Se usaron nanopartículas de dióxido de silicio como inhibidores de la pepsina para el tratamiento del reflujo gastroesofágico (GERD). Estas nanopartículas (SiO2NPs recubiertas de pepsina) son unas de las más seguras y pueden usarse en el cuerpo humano. Se midió a través de espectrofotometría la actividad de la pepsina antes y después de añadir cierta cantidad de NPs a la mezcla reactante. Adicionalmente, se repitieron estas pruebas a diferentes temperaturas, variando el peso de las NPs y la fuerza iónica. Se calcularon los parámetros cinéticos (Km y Vmax) de las reacciones catalizadas con pepsina a través de las gráficas de Lineweaver-Burk. Los resultados mostraron que, usando SiO2NPs (Vmax de pepsina libre = 4.82 U y Vmax de pepsina inmovilizada = 2.90 U) y a través de la presencia de fuerza iónica, la actividad enzimática se reduce significativamente. Se concluye que la mejor condición para inhibir la actividad enzimática es usando una combinación de SiO2NPs y una alta concentración de NaCl a 37 °C.

Foram usadas nanopartículas de dióxido de silício como inibidores da pepsina para o tratamento do refluxo gastroesofágico (GERD). Estas nanopartículas (SiO2NPs cobertas de pepsina) são uma das mais seguras e podem usar-se no corpo humano. Foi medida a atividade da pepsina mediante espectrofotometria antes e depois de agregar certa quantidade de NPs à mistura de reação. Adicionalmente, repetiram-se estas provas a diferentes temperaturas, variando o peso das NPs e a força iónica. Foram calculados os parâmetros cinéticos (Km e Vmax) das reações catalisadas com pepsina a través das gráficas de Lineweaver-Burk. Os resultados mostraram que, usando SiO2NPs (Vmax de pepsina livre = 4.82 U e Vmax de pepsina imobilizada = 2.90 U) e a través da presença de força iónica, a atividade enzimática se reduze significativamente. Foi concluído que a melhor condição para inibir a atividade enzimática é usando uma combinação de SiO2NPs e uma alta concentração de NaCl a 37 °C.

Determination of Uric Acid Based on Chitosan/Ru(bpy) 2+3/Silica Nanoparticles Electrochemiluminescence Sensor / 分析化学

Chitosan-Ru ( bpy ) 2+3 -SiO2 composite nanoparticles ( CRuS NPs ) were prepared by reverse microemulsion method, and based on the Nafion/MCNT composite membrane technology, CRuS NPs were effectively and steadily immobilize on the surface of a glassy carbon electrode to prepare the electrochemiluminescence sensor for uric acid determination. In 0. 1 mol/L PBS (pH 7. 4) buffer solution, when the actuation duration between uric acid and the modified electrode was 15 min, the electrochemiluminescence showed a good linear relationship to the negative logarithm of uric acid concentration in the range of 1. 0 × 10-10-1. 0 × 10-5 mol/L, the linear equation was IECL=-709. 52-202. 74lgC and the correlation coefficient was 0. 9936 with a detection limit of 6. 0 × 10-12 mol/L. The ECL sensor exhibited excellent repeatability and stability, and the RSD for 11 times determination of 1. 0 × 10-8 mol/L uric acid was 2. 9%. The recovery was 98. 5%-103. 5% in the determination of real Uric acid sample.

Uso de la nanopartícula de SiO 2 -TiO 2 en el tratamiento de úlceras en pie diabético: comunicación preliminar / Using SiO 2 - TiO 2 nanoparticle in the treatment of diabetic foot ulcers: preliminary communication

Resumen Una de las complicaciones más graves de la diabetes mellitus es el pie diabético, que resulta de la suma de factores como: macroangiopatía, microangiopatía y neuropatía que disminuyen el flujo vascular y causan pequeñas lesiones que rápidamente progresan a úlceras y pueden abarcar todos los tejidos; la clasificación de Wagner1 señala cómo se puede progresar de una pequeña lesión superficial a una profunda, y que se extienda a los tejidos profundos: tendones, músculos y aún hueso, y dañar gravemente la salud, con inminencia de muerte por sepsis. El tratamiento convencional tiene buenos resultados en general, pero requiere un cuidadoso programa de atención local, protección de mayores lesiones, antibióticos, etc., y si no hay resultado, puede terminar en amputación. La utilización de nanopartículas de óxidos metálicos, que consisten de dióxido de silicio (SiO2) y dióxido de tinanio (TiO2), preparadas mediante la técnica sol-gel, pueden ofrecer una alternativa viable en el tratamiento de la úlcera diabética, debido a un mecanismo que permite mantenerla seca y, al mismo tiempo, inhibe el crecimiento de bacterias mediante un efecto bíocatalítico2. Para evaluar el uso de estas nanopartículas en el pie diabético, se realizó un protocolo de investigación en un grupo de pacientes que acuden al Centro Especializado en la Atención del Paciente Diabético "Dr. Manuel González Rivera", dependiente de la Secretaría de Salud del Distrito Federal; este protocolo fue aprobado por la Dirección de Enseñanza e Investigación de la propia Secretaría, con el número de registro 101/100/014/13. Se estudió a 62 pacientes con diversas formas de úlcera diabética y se aplicaron las nanopartículas haciendo una curación cada 48 horas, fueron evaluadas con fotografías seriadas y cultivos de la úlcera. Todos los pacientes que recibieron el tratamiento lograron la curación, con desaparición de las úlceras y cicatrización satisfactoria. Conclusión: La aplicación tópica de las nanopartículas de SiO2 y TiO2 parece ser de utilidad en el tratamiento de la úlcera diabética.

Abstract One of the most severe complications of diabetes mellitus is the diabetic foot, which is the sum of macroangiopathy, microangiopathy and neuropathy, which leads to low vascular flow, and development of lesions which rapidly progress to ulcer and may attain all tissues; the Wagner classification1 shows how a little superficial lesion may affect all tissues: tendons, muscles and even bones, to severely affect the general health and may end on death by sepsis. The conventional treatment has good results, but requires a careful program of local attention, protection from larger lesions, antibiotics, etc., and if does not have good results, may ends on foot amputation. The use of nanoparticles of metallic oxides, silicium dioxide and titanium dioxide, prepared by the sol-gel technique, may offer a viable alternative for diabetic ulcer treatment due a mechanism which allows to keep it dry and at the same time, inhibit bacterial growing through a biocatalytic effect2. To evaluate the use of these nanoparticles in diabetic foot, a research protocol was established in a group of diabetic patients who attend to the Center Specialized on Handling of the Diabetic Patient from Mexico City of Secretary of Health; this protocol was approved by the Educations and Research Direction of the Secretary of Health. 62 diabetic patient with diabetic ulcers of different degree were studied; the nanoparticles were applied every 48 hours and evaluated with photos and bacterial cultures. All patients who received the complete treatment healed their ulcers, with satisfactory healing. Conclusion: The topical application of metallic oxides nanoparticles seems to be useful in the treatment of diabetic ulcers.

An Ultrasensitive Simultaneous Immunoassay Based on Arsenic and Mercury Ions Labeled SiO2@Au Nanoparticle Probes / 分析化学

An ultrasensitive immunoassay was developed based on As3+ and Hg2+ labeled SiO2 @ Au nanoparticles signal tags and hydride generation-atomic fluorescence spectrometry (HG-AFS) for the detection of carcinoembryonic antigen(CEA) and carbohydrate antigen 19-9 (CA 19-9) respectively. Firstly, amino SiO2@ Au NPs were synthesized for selective absorption of As3+ and Hg2+ ions respectively. Subsequently,the secondary antibody (Ab2) of CEA and CA 19-9 was respectively labeled on As3+ or Hg2+-SiO2 @ Au NPs to prepare the corresponding signal tags for CEA and CA 19-9. Based on the sandwich immunoassay scheme, the tags, two antigen and corresponding first antibodies were bio-conjugated on the bottom of 96-well plate at room temperature to form the immunocomplex. After it was dissolved in alkali solution, As3+ and Hg2+ ions were released in solution and detected by HG-AFS, which concentration was proportional with logarithms of CEA and CA 19-9. The reaction conditions were optimized and the tags were characterized. This assay was based on determination of the concentration of As3+ and Hg2+ for quantization of the corresponding CEA and CA 19-9 antigen. The assay showed a wide linear range from 0. 001 to 100. 0 μg / L for CEA and 0. 01-80 U/ mL for CA 19-9, and a lower detection limit of 0. 5 ng / L and 0. 005 U/ mL respectively. This proposed method was used in real serums samples, the results were consistence with that by ELISA. The immunoassay showed three orders of magnitude of sensitivity lower than that of ELISA, which provides a promising simultaneous immunoassay for the early diagnosis of cancer .

Negative Effect of Rapidly Resorbing Properties of Bioactive Glass-Ceramics as Bone Graft Substitute in a Rabbit Lumbar Fusion Model

BACKGROUND: Bioactive glass-ceramics have the ability to directly bind to bones and have been widely used as bone graft substitutes due to their high osteoconductivity and biocompatibility. CaO-SiO2-P2O5-B2O3 glass-ceramics are known to have good osteoconductivity and are used as bone graft extenders. METHODS: This study aimed to evaluate the effects of the resorbing properties of glass-ceramics in bone fusion after producing and analyzing three types of CaO-SiO2-P2O5-B2O3 glass-ceramics with high osteoconductivity that had enhanced resorption by having an increased B2O3 content. The three types of CaO-SiO2-P2O5-B2O3 glass-ceramics with B2O3 contents of 8.0, 9.0, and 9.5 weight % were designated and grouped as P20B80, P10B90, and P5B95, respectively. Glass-ceramic types were tested for fusion rates and bone formation by employing the lumbar 5-6 intertransverse process fusion model in 51 New Zealand male rabbits. Bioactivity was assessed by soaking in simulated body fluid (SBF). RESULTS: In vitro study results showed sufficient hydroxycarbonate apatite layer formation occurred for P20B80 in1 day, for P10B90 in 3 days, and for P5B95 in 5 days after soaking in SBF. For the rabbit lumbar spine posterolateral fusion model, the autograft group recorded a 100% fusion rate with levels significantly higher than those of P20B80 (29.4%), P10B90 (0%), and P5B95 (14.3%), with high resorbing properties. Resorbing property differences among the three glass-ceramic groups were not significant. Histological results showed new bone formation confirming osteoconductivity in all three types of glass-ceramics. Radiomorphometric results also confirmed the resorbing properties of the three glass-ceramic types. CONCLUSIONS: The high resorbing properties and osteoconductivity of porous glass-ceramics can be advantageous as no glass-ceramics remain in the body. However, their relatively fast rate of resorption in the body negatively affects their role as an osteoconductive scaffold as glass-ceramics are resorbed before bony fusion.

One-pot synthesis of 2-ARYL-1-ARYLMETHYL-1H-1,3-benzimidazole derivatives using sulfonic acid functionlized silica (SiO2-Pr-SO3H) under solvent free conditions.

2-Aryl-1-arylmethyl-1H-1,3-benzimidazoles were synthesized by the reaction of o-phenylendiamine with different types of aromatic aldehydes in the presence of Sulfonic acid functionlized silica (SiO2-Pr-SO3H) as solid acid catalyst under solvent free condition at room temperature in good to excellent yields.

Effect of Rho signaling pathway on SiO2 induced α-SMA expression in human bronchial epithelial cells / 中南大学学报(医学版)

Objective To investigate the role of Rho in SiO2 induced α-SMA expression in human bronchial epithelial cells (HBECs). Methods HBECs were cultured and stimulated with SiO2. Immunocytochemistry and Western blot were used to detect the expression of α-SMA. The activity of Rho was determined by GST pull down assay. In the prevention experiment,SiO2-stimulated HBECs were incubated with Rho inhibitor Y27632,and the expression of α-SMA was examined by Western blot. Results With SiO2 (0-300 μg/mL) treatment,the expression of α-SMA increased gradually,and 200 μg/mL of SiO2 led to the highest expression of α-SMA which was (5.09±1.98) times of the expression of α-SMA in the control group(P＜0.01). HBECs treated with SiO2 (200 μg/mL) for indicated time (1,2,6,12,and 24 h)showed an obvious increase of Rho activity(P＜0.01). Y27632 inhibited SiO2-induced α-SMA expression significantly,and the inhibition rate of 20 and 30 μmol/L Y27632 was 68% and 75%,respectively (P＜0.01).Conclusion Rho signaling pathway may mediate SiO2 induced α-SMA expression in HBECs.

ESTUDIO DRX EN MATERIALES CATALIZADORES Cu-Ni-SiO2 PARA HIDROGENACIÓN DE ACEITE DE SOYA. DESARROLLO DE ESTRUCTURA CRISTALINA Y ACTIVIDAD CATALÍTICA / DRX STUDY IN CATALYSTS MATERIAL Cu-Ni-SiO2 FOR HYDROGENATION OF SOY OIL. DEVELOPMENT OF CRYSTALLINE STRUCTURE AND CATALYTIC ACTIVITY / ESTUDO DRX EM MATERIAIS CATALISADORES Cu-Ni-SiO2 PARA HIDROGENACIÓN DE AZEITE DE SOYA. DESENVOLVIMENTO DE ESTRUTURA CRISTALINA E ATIVIDADE CATALÍTICA

Para buscar elementos experimentales que soporten la hipótesis según la cual se forman estructuras cristalinas Cu-Ni o, eventualmente, Cu-Ni-SiO2 en la síntesis de catalizadores para la hidrogenación de aceite de soya, se prepararon mezclas de estos tres materiales a partir de sales de los metales con sílice (aerosil). Se calcinaron a 270 °C y se redujeron a 330 °C en atmósfera de hidrógeno. En los materiales reducidos se estudió el difractógrama de RX en el rango 37 a 53°, y se comparó con el difractograma de aleaciones Cu-Ni -en las cuales se conoce la formación de cristales mixtos-, y con los difractogramas de los elementos puros Cu y Ni. Los resultados muestran señales de difracción diferentes a las señales de los componentes puros. La actividad catalítica se muestra diferente en los materiales que presentan distorsión en su estructura cristalina.

Looking for experimental facts that support the hypothesis of formation of Cu-Ni or Cu-Ni-SiO2 crystals formation hypo- thesis in the syntesis of catalytic materials for soja oil hydrogenation, different mixtures of the metals nitrates with SiO2 (aerosil), were prepared and calcined at 270 oC, then reduced in hydrogen atmosphere at 330 oC. RX Diffraction registers of the prepared materials, Ni-Cu alloys, Ni and Cu pure metals, show that differences in diffraction signal in prepared materials exist with respect to pure metals. The catalytic activity show differences too.

Para procurar elementos experimentais que suportem a hipótese segundo a qual se formam estruturas cristalinas Cu-Ni ou eventualmente Cu-Ni-SiO2 na síntese de catalisadores para a hidrogenación de azeite de soya, prepararam-se misturas destes três materiais a partir de sais dos metais com sílice (aerosil). Se calcinaron a 270 °C e se reduziram a 330 °C em atmosfera de hidrogênio. Nos materiais reduzidos se estudou o difractógrama de RX na casta 36 a 53 graus, e se comparou com o difractógrama de ligas de metais Cu-Nem, nas quais se conhece a formação de cristais mistos, e com os difractógramas dos elementos puros Cu e Nem. Os resultados mostram que se apresentam sinais de difracção diferentes aos sinais dos componentes puros. A atividade catalítica se mostra diferente nos materiais que apresentam distorção em sua estrutura cristalina.

HIDROGENACIÓN DE CITRONELAL SOBRE CATALIZADORES DE Ir/TiO2/SiO2 / HYDROGENATION OF CITRONELLAL OVER Ir/TiO2/SiO2 CATALYSTS / HIDROGENAÇÃO DE CITRONELAL EM CATALISADORES Ir/TiO2/SiO2

En este trabajo se estudió la hidrogenación selectiva de citronelal sobre sistemas de Ir/TiO2, Ir/SiO2, e Ir soportado en óxidos mixtos (Ir/TiO2-SiO2) reducidos a 473 y 773 K. Se analizó el efecto de la adición de TiO2 al soporte y de las temperaturas de reducción de los catalizadores para evaluar el posible efecto de especies TiOx parcialmente reducidas, sobre la actividad y selectividad de la reacción. Los sólidos resultantes se caracterizaron por quimisorción de hidrógeno a temperatura ambiente, adsorción de nitrógeno a 77 K, DRX, TEM y XPS. Los resultados indican que los catalizadores reducidos a alta temperatura (HT: 773 K) favorecen la producción del alcohol insaturado debido al efecto de interacción fuerte metal-soporte conocido como SMSI. Los catalizadores reducidos a baja temperatura (LT: 473 K) llevan a la ciclización del anillo produciendo isopulegol. Estos catalizadores mostraron una alta actividad y una menor selectividad hacia el alcohol insaturado.

Catalytic hydrogenation of citronellal over Ir/TiO2, Ir/SiO2, and Ir supported on mixed oxides (Ir/TiO2/SiO2) reduced at 473 y 773 K was studied. The effects of the partially reducible support species, the reduction temperatures (473 K or 773 K) and the successive TiO2 addition were analyzed. The catalysts were characterized by H2 chemisorption at room temperature, N2 adsorption at 77 K, XRD, TEM and XPS. The results showed that the high temperature reduction treatment (HT: 773 K) favored the production of the unsaturated alcohol, which can be explained in terms of the so-called strong metalsupport interaction (SMSI) effect. Catalysts reduced at low temperature (LT: 473 K) mainly led to a cyclization reaction producing isopulegol. These catalysts showed high activity but low selectivity to the unsaturated alcohol.

Nesse trabalho, foi estudada a hidrogenação seletiva do citronelal em catalisadores Ir/TiO2, Ir/SiO2 e Ir suportado em óxidos mistos (Ir/TiO2-SiO2) reduzidos a 473 e 773 K. Foi analisado o efeito da adição da TiO2 no suporte e das temperaturas de redução dos catalisadores para evaliar o possível efeito das espécies TiOx parcialmente reduzidas, sobre a atividade e seletividade da reação. Os sólidos resultantes foram caracterizados por quimisorção de hidrogênio a temperatura ambiente, adsorção de nitrogênio a 77 K, DRX, TEM e XPS. Os resultados indican que os catalisadores reduzidos a alta temperatura (HT: 773 K) favorecem a produção do álcool insaturado pelo efeito da interação forte metal-suporte conhecido como SMSI. Os catalisadores reduzidos a baixa temperatura (LT: 473 K) conduzen para a ciclização do anel produzindo isopulegol. Esses catalisadores mostraram uma alta atividade e uma baixa seletividade para álcool insaturado.