Comparative in vitro toxicity of a graphene oxide-silver nanocomposite and the pristine counterparts toward macrophages

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Graphene oxide (GO) is a highly oxidized graphene form with oxygen functional groups on its surface. GO is an excellent platform to support and stabilize silver nanoparticles (AgNP), which gives rise to the graphene oxide-silver nanoparticle (GOAg) nanocomposite. Understanding how this nanocomposite interacts with cells is a toxicological challenge of great importance for future biomedical applications, and macrophage cells can provide information concerning the biocompatibility of these nanomaterials. The cytotoxicity of the GOAg nanocomposite, pristine GO, and pristine AgNP was compared toward two representative murine macrophages: a tumoral lineage (J774) and peritoneal macrophages collected from Balb/c mouse. The production of reactive oxygen species (ROS) by J774 macrophages was also monitored. We investigated the internalization of nanomaterials by transmission electron microscopy (TEM). The quantification of internalized silver was carried out by inductively coupled plasma mass spectrometry (ICP-MS). Nanomaterial stability in the cell media was investigated overtime by visual observation, inductively coupled plasma optical emission spectrometry (ICP OES), and dynamic light scattering (DLS). Results: The GOAg nanocomposite was more toxic than pristine GO and pristine AgNP for both macrophages, and it significantly induced more ROS production compared to pristine AgNP. TEM analysis showed that GOAg was internalized by tumoral J774 macrophages. However, macrophages internalized approximately 60 % less GOAg than did pristine AgNP. The images also showed the degradation of nanocomposite inside cells. Conclusions: Although the GOAg nanocomposite was less internalized by the macrophage cells, it was more toxic than the pristine counterparts and induced remarkable oxidative stress. Our findings strongly reveal a synergistic toxicity effect of the GOAg nanocomposite. The toxicity and fate of nanocomposites in cells are some of the major concerns in the development of novel biocompatible materials and must be carefully evaluated.Graphene oxide (GO) is a highly oxidized graphene form with oxygen functional groups on its surface. GO is an excellent platform to support and stabilize silver nanoparticles (AgNP), which gives rise to the graphene oxide-silver nanoparticle (GOAg) nanoco14CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)140560/2014-9The authors thank the National Council for Technological and Scientific Development (CNPq) for the PhD student scholarship (140560/2014-9) and the financial support. The authors also acknowledge Dr. Daniel Ruiz Abanádes for suggestions, Renata Magueta fo

Translucency and masking ability of a translucent zirconia with different thicknesses over dark backgrounds

ABSTRACT Objectives: To evaluate the translucency, contrast ratio and masking ability of a translucent zirconia with different thicknesses. Methods: Disc shaped specimens (n= 3) with 10 mm (Ø) x 1.5 mm, 1 mm and 0.7 mm (thickness) were manufactured simulating all-ceramic simplified restorations. Substrate discs (n= 2; Ø: 10 mm; thickness: 2 mm) were simulated with composite resin shades: A2 (positive control) and C4; and metal alloys: silver (Ni-Cr) and golden (Cu-Al). Optical properties of the 9 translucent zirconia specimens placed on the 3 different substrates were analyzed by a spectrophotometer. The color variation (ΔE00) between each ceramic structure over the positive control substrate (A2) and over the dark backgrounds (C4, silvery, golden) were obtained as to their ceramic masking ability and subjected to non-parametric Kruskal Wallis test (5%). The translucency parameter (TP00) and contrast ratio (CR) of the different thicknesses of the ceramic discs were also collected and analyzed by one-way ANOVA and the Tukey test (5%). Results: The translucent zirconia showed greater opacity in the thickness of 1.5 mm, although it was not statistically different between 0.7 and 1.0 mm. All dark backgrounds significantly affected the final color of the simplified restoration in all evaluated thicknesses. However, the increase in ceramic thickness showed a decrease in ΔE00 values for all substrates. Conclusion: The translucent zirconia was not able to mask the dark substrates, independent of the evaluated thickness

Percutaneous ethanol injection versus conservative treatment for benign cystic and mixed thyroid nodules

ABSTRACT Objective To evaluate the efficacy and safety of percutaneous ethanol injection (PEI) in reducing the volume of cystic and mixed thyroid nodules. Materials and methods A total of 36 patients with nodules treated with PEI and 13 individuals who declined PEI and were followed clinically or received other non surgical treatment (control group). Assessments were performed at baseline (immediately before treatment in the PEI group or evaluation of the nodule on ultrasonography in the control group) at short-term (on average 30 days after the last injection in the PEI group), and long-term (on average 14 months after baseline in the PEI group or 26 months after baseline in the control group). Results In the PEI group, the mean baseline volume of 10.4 ± 9.8 cm3 reduced at short-term follow-up to 2.9 ± 3.1 cm3 (67.7 ± 19.9%, p < 0.001) and at long-term follow-up to 2.0 ± 2.5 cm3 (78.2 ± 19.5%, p < 0.01 versus baseline and p = 0.009 versus short-term follow-up). Both types of nodules showed similar degrees of reduction. In the control group, mean volume was 5.8 ± 3.4 cm3 at baseline and 6.2 ± 3.0 cm3 at long-term follow-up (p = 0.507). Compared with the control group, the PEI group showed larger reduction (p < 0.001). Conclusions PEI is effective in reducing the volume of cystic and mixed benign thyroid nodules, with sustained long-term efficacy and better outcome when compared with conservative therapies. Treatment with PEI is a safe alternative, with minimal, transient and self-limited adverse events

Percutaneous ethanol injection versus conservative treatment for benign cystic and mixed thyroid nodules

ABSTRACT Objective: To evaluate the efficacy and safety of percutaneous ethanol injection (PEI) in reducing the volume of cystic and mixed thyroid nodules. Materials and methods: A total of 36 patients with nodules treated with PEI and 13 individuals who declined PEI and were followed clinically or received other non surgical treatment (control group). Assessments were performed at baseline (immediately before treatment in the PEI group or evaluation of the nodule on ultrasonography in the control group) at short-term (on average 30 days after the last injection in the PEI group), and long-term (on average 14 months after baseline in the PEI group or 26 months after baseline in the control group). Results: In the PEI group, the mean baseline volume of 10.4 ± 9.8 cm³ reduced at short-term followup to 2.9 ± 3.1 cm³ (67.7 ± 19.9%, p &lt; 0.001) and at long-term follow-up to 2.0 ± 2.5 cm³ (78.2 ± 19.5%, p &lt; 0.01 versus baseline and p = 0.009 versus short-term follow-up). Both types of nodules showed similar degrees of reduction. In the control group, mean volume was 5.8 ± 3.4 cm³ at baseline and 6.2 ± 3.0 cm³ at long-term follow-up (p = 0.507). Compared with the control group, the PEI group showed larger reduction (p &lt; 0.001). Conclusions: PEI is effective in reducing the volume of cystic and mixed benign thyroid nodules, with sustained long-term efficacy and better outcome when compared with conservative therapies. Treatment with PEI is a safe alternative, with minimal, transient and selflimited adverse events. Arch Endocrinol Metab. 2016;60(3):211-

Percutaneous ethanol injection versus conservative treatment for benign cystic and mixed thyroid nodules

ABSTRACT Objective: To evaluate the efficacy and safety of percutaneous ethanol injection (PEI) in reducing the volume of cystic and mixed thyroid nodules. Materials and methods: A total of 36 patients with nodules treated with PEI and 13 individuals who declined PEI and were followed clinically or received other non surgical treatment (control group). Assessments were performed at baseline (immediately before treatment in the PEI group or evaluation of the nodule on ultrasonography in the control group) at short-term (on average 30 days after the last injection in the PEI group), and long-term (on average 14 months after baseline in the PEI group or 26 months after baseline in the control group). Results: In the PEI group, the mean baseline volume of 10.4 ± 9.8 cm³ reduced at short-term followup to 2.9 ± 3.1 cm³ (67.7 ± 19.9%, p &lt; 0.001) and at long-term follow-up to 2.0 ± 2.5 cm³ (78.2 ± 19.5%, p &lt; 0.01 versus baseline and p = 0.009 versus short-term follow-up). Both types of nodules showed similar degrees of reduction. In the control group, mean volume was 5.8 ± 3.4 cm³ at baseline and 6.2 ± 3.0 cm³ at long-term follow-up (p = 0.507). Compared with the control group, the PEI group showed larger reduction (p &lt; 0.001). Conclusions: PEI is effective in reducing the volume of cystic and mixed benign thyroid nodules, with sustained long-term efficacy and better outcome when compared with conservative therapies. Treatment with PEI is a safe alternative, with minimal, transient and selflimited adverse events