RESUMO

Among the essential oils (EOs), the cabreuva essential oil extracted from the wood of Myrocarpus fastigiatus, is a promising compound for potential applications in the field of pharmaceuticals and food packaging. To overcome the low solubility of cabreuva EO and to protect it, a two-step process, emulsion formation compound by chitosan, SDS, and PVA, and subsequent ionic crosslinking with sodium citrate, was proposed. The formulation containing 0.75% of chitosan and 1% of SDS proved to be the most stable. An alternative to produce nanostructures and encapsulate the EO is the fiber formation through the electrospinning method. The system composed by a PVA solution assembled with crosslinked emulsions modified the viscosity, influencing the morphology of the obtained nanofibers. The advantage of the electrospun nanofibers was their ability to be an effective carrier of the cabreuva EO and the capacity of controlling the compound release that proved an effective activity against broad spectra of micro-organisms (Candida albicans, E. coli, S. aureus, and S. epidermidis). The Gallagher-Corrigan model, used to fit the release profiles of matrices in contact with increasing ethanol proportion from 25:75 to 50:50 showed higher Kb in relation to k suggesting that the polymer swelling played an increasingly prominent role in the EO delivery. The developed nanostructures would be materials with potential applications in the biomedical field.

Assuntos

Quitosana/química , Emulsões/química , Nanofibras/química , Óleos Voláteis/química , Álcool de Polivinil/química , Embalagem de Alimentos/métodos , Nanoestruturas/química , Polímeros/química , Solubilidade , Viscosidade

RESUMO

In recent years, the use of commercial nanoparticles in different industry and health fields has increased exponentially. However, the uncontrolled application of nanoparticles might present a potential risk to the environment and health. Toxicity of these nanoparticles is usually evaluated by a fast screening assay in zebrafish (Danio rerio). The use of this vertebrate animal model has grown due to its small size, great adaptability, high fertilization rate and fast external development of transparent embryos. In this review, we describe the toxicity of different micro- and nanoparticles (carbon nanotubes, dendrimers, emulsions, liposomes, metal nanoparticles, and solid lipid nanoparticles) associated to their biophysical properties using this model. The main biophysical properties studied are size, charge and surface potential due to their impact on the environment and health effects. The review also discusses the correlation of the effects of the different nanoparticles on zebrafish. Special focus is made on morphological abnormalities, altered development and abnormal behavior. The last part of the review debates changes that should be made in future directions in order to improve the use of the zebrafish model to assess nanotoxicity.