Silver nanoparticles (AgNPs) have important antimicrobial activity. These nanoparticles are present in several commercial products, leading to human and environmental exposure. This review presents a critical view of the toxic effects of Ag NPs on in vitro and in vivo biological models. It is noteworthy that the toxicity of AgNPs is dependent on several parameters, such as the preparation mode of the colloidal suspension of the nanoparticles, their state of aggregation, the chemical nature of the nanoparticles, surface size, morphology, dose, cell type, nature of the living organism, among others. In general, low concentrations of AgNPs do not present significant toxicity in in vitro and in vivo assays, however with the increase of the concentration of AgNPs there is a significant increase of nanoparticle toxicity and its accumulation in diverse tissues/organs. It should be emphasized that in living organisms, exposure routes should be taken into account, such as ingestion and inhalation. At high concentrations, inhalation or ingestion of AgNPs can cause adverse effects and even lead to human death. In this context, the importance of further studies of the toxicity of AgNPs in several in vitro and in vivo models is emphasized.

This overview highlights the importance of characterization of biogenic nanoparticles of silver and silver chloride in order to understand the action on ticks or pathogens transmitted by them. These nanoparticles appear as important active principles in this area. They can act against ticks or against major pathogens transmitted by the bite of ticks such as bacteria, viruses or protozoa with equal or better efficacy of antibiotics, antiviral or antiparasitic agents. Anti-tick activities on Rhipicephalus (Boophilus) microplus, Hyalomma anatolicum, Hyalomma isaaci and Haemaphysalis bispinosa are discussed. Perspectives of these nanoparticles acting on bacteria, viruses and protozoa infections are also discussed.

United Nations Children's Fund (UNICEF)/United Nations Development Programme (UNDP)/World Bank/World Health Organization (WHO) implemented the Training in Tropical Diseases (TDR) program with excellent results; however, due to current challenges, this active program requires new and innovative solutions. Nowadays, Aedes aegyptis-borne diseases can be added among neglected diseases. Surveillance and control must be considered owing to a great risk of infection with dengue, chikungunya and zika viruses. Although investigations on several vaccines are in progress, new insights in term of development of drugs that evade from resistance are of paramount importance. Nanobiotechnology appears as one of the most innovative strategy in the search of new uses for old pharmaceuticals or in the development of innovative and intelligent nanomedicines for neglected diseases. Liposomes, solid lipid nanoparticles, nanoemulsions, polymeric nanoparticles, metallic nanoparticles, quantum dots, carbon dots and carbon nanotubes were the focus of the current advances. In this direction, we have focused this overview on new advances in diagnostic assays as nanobiosensors, antivirus and nanoinsecticides on Aedes aegyptis control.

Cellulose nanocrystals appeared as important bio-based products and the collected information in term of production, characterization and application suggest that this nanomaterial could be easily extrapolated to bioethanol production. This review describes recent published syntheses using chemical and enzymatic hydrolyses and different preparations such as high pressure homogenization. Their industrial and medical applications, such as controled of delivery carriers, suggest a large projection of this nanomaterial. The most important aspect in this collected data is the potential to decrease significantly the final cost of the enzymes or the hydrolysis pre-treatment of lignocellulosic materials of all bioethanol processes in such a way that it could be economically feasible from materials such as bagasse, straw or wood resources.

The use of poorly water soluble molecules in pharmaceutical area has grown. Since these molecules exhibit low oral bioavailability, they are not used in intravenous administrations. Therefore, it is necessary to develop their new formulations with the aim to increase their oral bioavailabilities as to enable intravenous applications. One of the few possibilities in achieving this is a nanonization process that can produce crystals smaller than 1 μm by high pressure homogenization and without use of organic solvents. This mini-review describes technical aspects of the nanocrystal production, morphological aspects (polymorphisms), the market relevance of the nanocrystals products that are already in clinical phase or at the market, as well as, perspectives for the near future.