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BACKGROUND: Due to its strong catalytic activity and selective catalytic oxidation, gold-silver bimetallic nanoparticles have potential applications in biomedicine, drug delivery and electrochemical analysis.OBJECTIVE: To prepare the gold-silver alloy nanoparticles using mitochondria in animal cells as templates. METHODS: Separating mitochondria from the fish liver: 1 mL of mitochondrial mother liquor was added into 1 mL of alkaline HAuCl4solution (10 mmol/L) and shaken; then, 1 mL of AgNO3solution (10 mmol/L) was added, and the mixture was reacted in an electromagnetic stirrer for 20-30 hours until the color of the reaction solution was changed from colorless to purple, which indicated that gold and silver alloy nanoparticles were successfully obtained; finally, the characterization of the nanoparticles was analyzed. (1) Cytotoxicity test: gold-silver alloy nanoparticles atdifferent concentrations (0, 25, 50, 75, 100, 125, 150 mg/L) were added into gastric cancer cells. After 48 hours of culture, the proliferation of cells (absorbance value) was detected by MTT assay. (2) Stability evaluation: 1 mL of gold-silver alloy nanoparticles at different concentrations (0, 25, 50, 75, 100, 125, 150 mg/L) were placed into glass reaction flasks and then, 0.2 mL of ultrapure water was added in portions following by shaking. After addition of the ultra-pure water, ultraviolet-visible spectrum was used to analyze the characterization of the solution. RESULTS AND CONCLUSION: The gold-silver alloy nanoparticles were spherically distributed and confirmed to have an alloy structure with the average particle size of 20-30 nm, and presented to have the advantages of simple structure, good crystallinity, and active groups such as hydroxyl and carbonyl groups on the surface. MTT results showed that the gold-silver alloy nanoparticles at the mass concentration of < 150 mg/L had no obvious cytotoxicity. The characteristic absorption peak with the largest intensity was positively correlated with the concentration of gold-silver alloy nanoparticles.To conclude,the gold-silver alloy nanoparticles have good cytocompatibility and stability in vitro.
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Objective It is demostrated that the porous protein mineral mechanics model could provide more accurate prediction for biomaterial properties of dentine compared with the other established models. This paper would use the model to reevaluate the mechanical properties and its interacting mechanism of human dentine. Method By using a porous protein mineral mechanics model, the effect from the interactions between tubules, peritubular and intertubular matrix on dentine microstructure was discussed. Results The dentinal micromechanical properties were dependent on the tubular direction, and the absolute values of the stresses derived from the hydraulic and gas tubular pressures increased parabolically with the increasing diameter of the tubules. It was also found that the effective elastic constants of the dentine microstructure would vary with the aging and the distribution of mineral and collagen within peritubular and intertubular matrix of detine. Conclusions The theoretical analyses provided in this paper demonstrated that the microstructural characteristics of tubules, peritubular and intertubular dentinal matrix could have different influences on the micromechanical properties of human dentine, which showed the validity of porous protein mineral mechanics model, and the limitation of some models that neglected the interacting mechanism.
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Objective:It is demostrated that the porous protein-mineral mechanics model could provide more accurate prediction for biomaterial properties of dentine compared with the other established models.This paper would use the model to reevaluate the mechanical properties and its interacting mechanism of human dentine.Method:By using a porous proteinmineral mechanics model,the effect from the interactions between tubules,pedtubular and intertubular matrix on dentine microstructure was discussed.Results:The dentinal micromechanical properties were dependent on the tubular direction,and the absolute values of the stresses derived from the hydraulic and gas tubular pressures increased parabolically with theincreasing diameter of the tubules.It was also found that the effective elastic constants of the dentine microstructure would vary with the aging and the distribution of mineral and collagen within peritubular and intertubular matrix of detine.Conclusions:The theoretical analyses provided in this paper demonstrated that the microstructural characteristics of tubules,peritubular and intertubular dentinal matdx could have different influences on the micromechanical properties of human dentine,which showed the validity of porous protein-mineral mechanics model,and the limitation of some models that neglected the interacting mechanism.
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Objective:It is demostrated that the porous protein-mineral mechanics model could provide more accurate prediction for biomaterial properties of dentine compared with the other established models.This paper would use the model to reevaluate the mechanical properties and its interacting mechanism of human dentine.Method:By using a porous proteinmineral mechanics model,the effect from the interactions between tubules,pedtubular and intertubular matrix on dentine microstructure was discussed.Results:The dentinal micromechanical properties were dependent on the tubular direction,and the absolute values of the stresses derived from the hydraulic and gas tubular pressures increased parabolically with theincreasing diameter of the tubules.It was also found that the effective elastic constants of the dentine microstructure would vary with the aging and the distribution of mineral and collagen within peritubular and intertubular matrix of detine.Conclusions:The theoretical analyses provided in this paper demonstrated that the microstructural characteristics of tubules,peritubular and intertubular dentinal matdx could have different influences on the micromechanical properties of human dentine,which showed the validity of porous protein-mineral mechanics model,and the limitation of some models that neglected the interacting mechanism.
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AIM: To investigate the effects of pioglitazone on corneal neovascularization(CNV)induced by alkali burnin rats and on expression of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (b-FGF).METHODS: CNV was induced by alkaline burn in rats which were then administered pioglitazone subconjunctivally.Corneal angiogenesis was evaluated and observed with a slit lamp microscope and the VEGF and b-FGF level were determined by immunohistochemistry and Western blot at different intervals.RESULTS: The CNV of the rats was shown two days after alkaline burn, and reached its highest level in 7-10 days. The mean values of the area and length of neovascularization and the VEGF and b-FGF levels in the pioglitazone-treated group were significantly lower than those in the control group at various time.CONCLUSTON: Local application of pioglitazone could remarkably inhibit CNV, probably by means of downregulation of VEGF and b-FGF expression.
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To prevent acute graft-versus-host disease (aGVHD), glucosidorum tripterygii tororum (GTT) was used in the murine model. The lethally irradiated C57BL/6 recipients were injected with bone marrow and lymphocyte grafts from BALB/c donors and were treated intraperitoneally with GTT, cyclosporine A (CsA), or methotrexate (MTX). T lymphocytes, adhesion molecules and cytokines were detected by immunohistochemical method, flow cytometry, ELISA and RT-PCR, respectively. The results showed that all the control recipient mice (21/21) died of aGVHD within 30 days, but many recipient mice treated with GTT (19/21), CsA + MTX (13/21) and GTT + CsA (17/21) survived beyond 30 days without obvious signs of aGVHD. The numbers of CD3(+), CD4(+), CD8(+), CD11a(+), CD18(+) lymphocytes in skin and lung decreased markedly by GTT, GTT + CsA and CsA + MTX treatments. The numbers of CD3(+), CD4(+), CD8(+), CD4(+)CD11a(+), CD4(+)CD18(+), CD8(+)CD11a(+), CD8(+)CD18(+) lymphocytes in spleen decreased markedly by GTT, GTT + CsA and CsA + MTX treatments. and the changes of CD3(+), CD4(+), CD8(+) cells in small intestine were not remarkable (P > 0.05) by above mentioned GTT, GTT + CsA and CsA + MTX treatments. The serum concentrations and mRNA expressions of IL-2 and TNFalpha in spleens decreased significantly (P < 0.05); the concentration of IL-10 increased significantly (P < 0.05), the change of IL-4 was not remarkable (P > 0.05) by GTT treatment. It is concluded that the GTT may retain the graft-versus-leukemia (GVL) effect of transplant without aGVHD. The role of GTT in prevention of murine aGVHD is mediated by reduction of T lymphocytes and their subgroups, expression of adhesion molecule, and regulation of cytokine secretion.