Gold-based nanospheres and nanorods particles used as theranostic agents: An in vitro and in vivo toxicology studies

The adverse effect of gold-based nanoparticles is still an open question since it depends on several factors as shape, surface charge or route of administration. In this study, we investigated the influence of shape and human serum albumin (HSA) coating on the adverse effects of spherical (AuNP) and nanorods (AuNR) gold-based particles. F C3H (fibroblast) and HTC (hepatocellular carcinoma) cell lines both from liver were exposed to 25, 75 and 125 μg mL^-1, which correspond to 10⁹ NP mL^-1. For in vivo studies, Wistar rats received these materials by oral administration in doses of 10 μg kg^-1 or 40 μg kg^-1. Systemic toxicity was verified after 24 h and 48 h by morphological analysis, blood parameters and myeloperoxidase enzyme activity. Our results revealed that HSA corona does not influence totally the pathway of interactions between AuNP and AuNR. In vitro results evidenced that AuNP can decrease in at least 50% viability of F C3H and cell adhesion of HTC, but corona significantly overcomes these effects. No differences between shape or corona were observed in function of cell lines. In vivo studies showed that 40 μg kg^-1 of AuNP-HSA caused an enhancement of the myeloperoxidase response indicating inflammatory processes. An increase from 40% to 80% on alkaline phosphatase levels were found for all groups. Our findings suggested that gold-based particles coated or not with HSA do not cause expressive adverse effects on in vitro or in vivo systems, and their oral administration cannot cause a systemic effect in the experimental conditions used here.

Supplementation of Glutamine and Vitamin E on the Morphometry of the Intestinal Mucosa in Broiler Chickens

The objective of this experiment was to evaluate the influence of Gln and vitamin E (VE) supplementation in the diet of broiler chickens (Cobb-Vantress) on the morphometry of the intestinal mucosa. The design was completely randomized in a 2 x 3 (VE x periods of administering Gln) factorial arrangement. The levels of VE used were 10 and 500 mg/kg of diet and 3 periods of administering (1%) Gln-supplemented starter diet (for the first 7 or 14 d of life or for no added Gln), totaling 6 treatments with 5 replicates of 50 birds per experimental unit. In the growth period (d 22 to 41 posthatch), the treatments consisted only in the respective levels of VE. On d 7, 14, 21, and 41 posthatch, 2 birds per replicate were killed, and samples of the duodenum, jejunum, and ileum were subsequently removed, fixed in Bouin solution, and later embedded in paraffin and stained with hematoxylin-eosin. The parameters analyzed were villus height and crypt depth. An ANOVA was applied to the obtained data, and the means were compared using Tukey's test (5% significance level). Greater development was observed in the duodenum, followed by the jejunum and ileum. On 41 d of life, diets with 10 mg of VE/kg supplemented with Gln (for the first 7 d of life) provided better development of the intestinal mucosa in broiler chickens.

Morphometric and quantitative evaluation of the NADH-diaphorase positive myenteric neurons of the jejunum of streptozotocin-diabetic rats supplemented with acetyl-L-carnitine

Summary In this study we investigated the effect of the acetyl-L-carnitine (ALC) supplementation on the myenteric neurons of the jejunum of rats made diabetic at the age of 105 days by streptozotocin (35 mg/kg body weight). Four groups were used: non-diabetic (C), non-diabetic supplemented with ALC (CC), diabetic (D), diabetic supplemented with ALC (DC). After 15 weeks of diabetes induction the blood was collected by cardiac puncture to evaluate glycaemia and glycated haemoglobin. Next the animals were killed and the jejunum was collected and subjected to whole-mount preparation to evidence the myenteric neurons through the histochemical technique of the NADH-diaphorase. The neuronal counts were made in 80 microscopic fields, in tissue samples of five animals of each group. The profiles of the cell bodies of 1000 neurons per group were analysed. Diabetes induced a significant increase in the area of the cell body and decrease in the number of NADH-diaphorase positive myoenteric neurons. ALC suplementation to the diabetic group promoted smaller hypertrophic effects and less neuronal loss than in the myoenteric neurons of the diabetic rats, and in addition diminished the body weight decrease and reduced the fasting glycaemia.