Transfer of Silica-Coated Magnetic (Fe₃O₄) Nanoparticles Through Food: A Molecular and Morphological Study in Zebrafish

Abstract

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.

Biogenic Supported Lipid Bilayers from Nanosized Extracellular Vesicles

“…Confocal Laser Scanning Microscopy : CLSM experiments were carried out with a laser scanning confocal microscope Leica TCS SP2 (Leica Microsystems GmbH, Wetzlar, Germany) equipped with a 63× water immersion objective . Before SLB deposition, POPC liposomes and EVs were fluorescently labeled with Bodipy and DiIC20, deposited to form SLBs on the borosilicate cover glass of a well and extensively washed with MilliQ water, to remove any possible weakly bound species, as previously described.…”

Presence and distribution of leptin and its receptor in the gut of adult zebrafish in response to feeding and fasting

“…The zebrafish, for its morphological and molecular similarities with mammals, is widely used in biomedical research Piccinetti et al., ) indeed gastrointestinal apparatus is currently utilized to mimic the gut disorders (Goldsmith & Jobin, ; Viña et al., ). Thus, this study was undertaken in order to analyse the presence and distribution of leptin and its receptor and to better evaluate the change in the expression of leptin and leptin receptor mRNA in response to food stimuli in the intestine of adult zebrafish.…”

Hybrid vesicles from lipids and block copolymers: Phase behavior from the micro- to the nano-scale

“…Confocal Microscopy experiments were carried out with a Leica TCS SP2 Confocal Microscope (Leica Microsystems). [22] The fluorescent dyes β-Bodipy and DiI-C20 were excited respectively at 488 nm, with an Ar laser, and 561 nm, with DPSS 561 laser, and the fluorescence was collected with PMTs in the wavelength ranges 498-530 nm and 571-630 nm, respectively. It must be noted that in order to facilitate the formation of PBD-PEO GUVs of sufficient size and their detachment from the film, which is necessary for confocal microscopy visualization, for the preparation of pure copolymer-based vesicles, PBD-PEO was mixed with 20 mol % PBD-PEO-COOH.…”