Nanoparticles
Transfer of silica-coated magnetic (Fe3O4) nanoparticles through food: a molecular and morphological study in zebrafish
Autori: Piccinetti CC, Montis C, Bonini M, Laurà R, Guerrera MC, Radaelli G, Vianello F, Santinelli V, Maradonna F, Nozzi V, Olivotto I
Riferimenti: Zebrafish (2014) 11, 567-579.
Summary: The increasing use of magnetic iron oxide nanoparticles (NPs) in biomedical applications has prompted extensive investigation of their interactions with biological systems also through animal models. A variety of toxic effects have been detected in NP-exposed fish and fish embryos, including oxidative stress and associated changes, such as lipid oxidation, apoptosis, and gene expression alterations. The main exposure route for fish is through food and the food web. This study was devised to investigate the effects of silica-coated NP administration through food in zebrafish (ZF, Danio rerio). Silica-coated magnetic NPs were administered to ZF through feed (zooplankton) from day 1 to 15 posthatching (ph). Larvae were examined 6 and 15 days ph and adults 3 and 6 months ph. A multidisciplinary approach, including morphometric examination; light, transmission electron, and confocal microscopy; inductively coupled plasma emission spectrometry; and real-time polymerase chain reaction, was applied to detect NP accumulation, structural and ultrastructural damage, and activation of detoxification processes in larvae and adults. Our findings document that the silica-coated NPs: (1) do not induce toxicity in ZF, (2) are excreted through feces, and (3) do not activate detoxification processes or promote tissue/cell injury.
Link: https://www.liebertpub.com/doi/full/10.1089/zeb.2014.1037
Oxytetracycline delivery in adult female zebrafish by iron oxide nanoparticles
Autori: Chemello G, Piccinetti C, Randazzo B, Carnevali O, Magro M, Bonaiuto E, Vianello F, Radaelli G, Olivotto I
Riferimenti: Zebrafish (2016) 13, 495-503.
Summary: Recently, the indiscriminate use of antibiotics in the aquaculture sector has raised public concern because of possible toxic effects, development of bacterial resistance, and accumulation of residues in individual tissues. Even if several countries have developed regulations about their use, it is clear that long-term growth of the aquaculture industry requires both ecologically sound practices and sustainable resource management. Alternative strategies for better management of antibiotic administration are of primary interest to improve absorption rates and, as a consequence, to reduce their release into the aquatic environment. The present study investigates, for the first time to our knowledge, a new methodology for oxytetracycline (OTC) administration through the use of iron oxide nanoparticles (NPs) (made of maghemite γ-Fe2O3) in zebrafish (Danio rerio). Fish were divided into 4 experimental groups: control; group A exposed to 4 mg/L OTC (through water); group B exposed to the 100 mg/L SAMNs@OTC complex (equivalent to 4 mg/L OTC), and group C exposed to bare NPs. No detoxification processes or anatomical alterations were observed in fish exposed to bare NPs. Exposure of fish to the SAMNs@OTC complex resulted in a 10 times higher OTC accumulation with respect to using water exposure. This new OTC administration method seems much more efficient with respect to the traditional way of exposure and has the potentiality to reduce antibiotic utilization and possible environmental impacts. However, the dynamics related to OTC release from the SAMNs@OTC complex are still not clear and need further investigations.
The surface reactivity of iron oxide nanoparticles as a potential hazard for aquatic environments: A study on Daphnia magna adults and embryos
Autori: Magro M, De Liguoro M, Franzago E, Baratella D, Vianello F
Riferimenti: Scientific Reports (2018) 8, 13017.
Summary: Nano-ecotoxicology is extensively debated and nanomaterial surface reactivity is an emerging topic. Iron oxide nanoparticles are widely applied, with organic or inorganic coatings for stabilizing their suspensions. Surface active maghemite nanoparticles (SAMNs) are the unique example of naked iron oxide displaying high colloidal and structural stability in water and chemical reactivity. The colloidal behavior of SAMNs was studied as a function of the medium salinity and protocols of acute and chronic toxicity on Daphnia magna were consequently adapted. SAMN distribution into the crustacean, intake/depletion rates and swimming performances were evaluated. No sign of toxicity was detected in two model organisms from the first trophic level (P. subcapitata and L. minor). In D. magna, acute EC50 values of SAMN was assessed, while no sub-lethal effects were observed and the accumulation of SAMNs in the gut appeared as the sole cause of mortality. Fast depuration and absence of delayed effects indicated no retention of SAMNs within the organism. In spite of negligible toxicity on D. magna adults, SAMN surface reactivity was responsible of membrane bursting and lethality on embryos. The present study offers a contribution to the nascent knowledge concerning the impact of nanoparticle surface reactivity on biological interfaces.
Safety assessment of antibiotic administration by magnetic nanoparticles in in vitro zebrafish liver and intestine cultures
Autori: Chemello G, Randazzo B, Zarantoniello M, Fifi AP, Aversa S, Ballarin C, Radaelli G, Magro M, Olivotto I
Riferimenti: Comp Biochem Physiol C Toxicol Pharmacol (2019) Jun 26: 108559
Summary: Different in vitro models have been suggested to replace in vivo studies. In vitro studies are of great interest and give the opportunity to analyze cellular responses in a closed system with stable experimental conditions and to avoid direct animal exposure and distress during the experiments. These methods are useful to test drugs and chemicals toxicity in order to better understand their environmental impact. In the present study, fish organ cultures have been used to test different oxytetracycline exposure methods, including oxide nanoparticles (IONPs), using zebrafish as experimental model. Results showed that oxytetracycline accumulation at the end of the experiment (24 h) in the exposed organs did not show any significant difference in the analyzed samples and was not dependent on the exposure way (free or IONPs-bound oxytetracycline). However, as regards molecular analysis, the different exposure ways tested in this study showed some differences in the expression of genes involved in stress response. The present data did not completely agree with a previous in vivo study performed in zebrafish using IONPs, underlying that replacement of in vivo models with in vitro studies cannot always represent the complexity of interactions typical of a biological system.
