Nanotechnologies applied to antibiotic delivery in Zebrafish (Danio rerio)

Tons of drugs are produced annually worldwide for consumption by humans or use in the treatment of animals. The release and presence of drugs in the environment is a highly hot topic, which was firstly highlighted in the US in the 70's and almost a decade later in England. Yet, it was in the mid-90s, with the progress of analytical techniques, that the knowledge about environmental contamination caused by these compounds excelled considerably. Most of these drugs are poorly metabolized by animals after ingestion and a fraction ranging from 25% to 75% may be released into the environment after consumption Rivas et al. (2011). Recent studies have shown concentrations of different types of drugs in wastewater, surface waters, in sea water, groundwater and drinking water equal to mg-ng L-1. The scientific community clearly states that the presence of pharmaceutical products cause adverse effects not only to aquatic ecosystems but also to human health. Especially antibiotics and antiparasitic drugs are abundantly used for veterinary purposes. Oxytetracycline is one of the most commonly, wide spectrum, antibiotics used, typically administered orally, (incorporated into pellet feed) or via water. This antibiotic is characterized by a poor adsorption (25 to 30%) that often results in the production of large amounts of wastes. The release of these wastes into the aquatic environment can cause serious threat to aquatic organisms. As a consequence, a better management of antibiotic administration is considered of primary importance. At this regard, nanotechnologies, and in particular nanoparticles (NP) are looked with great interest because of their unique chemical-physical properties that make them ideal for several biomedical applications, including drug delivery Piccinetti et al. (2014). Piccinetti CC., Montis C., Bonini M., et al. 2014. Transfer of Silica-Coated Magnetic (Fe3O4) Nanoparticles Through Food: A Molecular and Morphological Study in Zebrafish. Zebrafish 11: 567-579.