Assessing the toxicity of one-step-synthesized PEG-coated gold nanoparticles: in vitro and in vivo studies

ABSTRACT Objective To evaluate the in vitro and in vivo toxicities of polyethylene glycol-coated gold nanoparticles synthesized using a one-step process. Methods Gold nanoparticles were prepared via a co-precipitation method using polyethylene glycol, and the synthesis product was characterized. For the in vitro evaluation, a flow cytometry analysis with Annexin V and iodide propidium staining was used to assess cytotoxicity in MG-63 cells labeled with 10, 50, and 100µg/mL of nanoparticle concentration. For the in vivo evaluation, nanoparticles were administered intraperitoneally at a dose of 10mg/kg dose in 10-week-old mice. Toxicity was assessed 24 hours and 7 days after administration via histopathological analysis of various tissues, as well as through renal, hepatic, and hematopoietic evaluations. Results Synthesized nanoparticles exhibited different hydrodynamic sizes depending on the medium: 51.27±1.62nm in water and 268.12±28.45nm (0 hour) in culture medium. They demonstrated a maximum absorbance at 520nm and a zeta potential of -8.419mV. Cellular viability exceeded 90%, with less than 3% early apoptosis, 6% late apoptosis, and 1% necrosis across all labeling conditions, indicating minimal cytotoxicity differences. Histopathological analysis highlighted the accumulation of nanoparticles in the mesentery; however, no lesions or visible agglomeration was observed in the remaining tissues. Renal, hepatic, and hematopoietic analyses showed no significant differences at any time point. Conclusion Polyethylene glycol-coated gold nanoparticles exhibit extremely low toxicity and high biocompatibility, showing promise for future studies.

Caracterização analítica de sucos e néctares de laranja adoçados com sacarose e edulcorantes / Analytical characterization of orange juices and nectars sweetened with sucrose and sweet flavoring agents

Objetivo: Caracterizar físico-quimicamente, sucos não adoçados e néctares de laranja adoçados com sacarose ou edulcorantes, quanto ao seu pH, acidez titulável (AT) e teor de sólidos solúveis totais (SST) e avaliar a correlação desta última propriedade com as demais. Método: Analisaram-se alíquotas de três lotes de dois sucos de laranja e de dois néctares com adição de sacarose ou dois com edulcorantes. Água mineral foi empregada como controle. O teor de SST foi determinado em refratômetro de Abbé. O pH foi registrado em peagômetro digital, enquanto a AT foi quantificada titulando-se amostras das bebidas com NaOH 0,1 M até o alcance dos pHs 5,5 e 7,0. Os dados foram submetidos ao teste de correlação de Pearson, análise de regressão, análise de variância e teste de Tukey (alfa = 0,05). Resultados: Os teores de SST apresentaram forte correlação com a AT, sendo a relação entre elas do tipo quadrática. Embora os valores de pH não sejam dependentes da presença de sacarose ou edulcorantes, se as bebidas são isentas dos mesmos, significativamente maior quantidade de base foi necessária para que se atingissem os pHs 5,5 e 7,0. Conclusão: Sucos e néctares de laranja apresentaram valores semelhantes de pH, os quais não se correlacionaram com a presença de sacarose ou edulcorantes nas bebidas. A acidez titulável foi maior para o suco e menor para os néctares, independentemente do fato de possuírem sacarose ou edulcorantes em sua composição. A elevação do teor de sólidos solúveis totais não implicou em redução da acidez titulável das bebidas.

Objective: To characterize physically and chemically, non-sweetened orange juices and orange nectars sweetened with sucrose or sweet flavoring agents, with respect to their pH, titratable acidity (TA) and total soluble solids content (TSSC), as well as to evaluate the correlation of the latter property with the others. Method: Aliquots of three lots of two orange juices and two orange nectars containing sucrose and two containing sweet flavoring agents were evaluated. Mineral water was used as a control. The TSSC was determined using an Abbe refractometer. The pH was recorded using a digital pH meter, while TA was quantified by titrating samples of the beverages with 0.1 M NaOH until reaching pHs 5.5 and 7.0. Data were subjected to Pearson's correlation test, regression analysis, analysis of variance and Tukey's test (alpha=0.05). Results: TSSC values presented a strong correlation with TA, and these properties exhibited a quadratic relationship. Although the pH values were not dependent on the presence of sucrose or sweet flavoring agents, a significantly greater amount of base was necessary to reach pHs 5.5 and 7.0 in the beverages without sucrose or flavoring agents. Conclusion: Orange juices and nectars presented similar pH values, which was not associated with the presence of sucrose or sweet flavoring agents in the beverages. Higher TA values were obtained for the juice and lower for the nectars, regardless of containing sucrose or sweet flavoring agents. The increase of TSSC did not implicate in decrease of TA in the beverages.