THE USE OF ZEBRAFISH EMBRYOS TO EXPLORE DIFFERENT NATURAL POLYPHENOL APPLICATIONS

Lignin and tannins are natural polyphenols abundantly present on Earth. These aromatic biopolymers have gained interest in different fields due to their attractive properties[1-3], especially in the form of nanocapsules (NCs) and nanoparticles (NPs)[4]. Zebrafish embryos can be efficiently employed to investigate their biomedical applications, not only to test these natural nano-formulations in a living organism, but also to evaluate their interactions, toxicity, and behavior in the biological milieu[5]. Two case studies are here reported. The first is based on demonstrating in an inducible zebrafish embryo model of Alzheimer’s Disease (AD) that a multifunctional tannin-based carrier system is suitable for in vivo MRI and difference-fluorescence imaging. The second project aims at testing the anti-inflammatory properties of sonochemically nano-formulated pristine lignin (LigNPs) and enzymatically-phenolated lignin (PheLigNPs)[6], in two different zebrafish inflammatory models. The data obtained demonstrated that the NCs and NPs related to each project showed negligible toxicity, besides the capacity to induce a positive response during an inflammatory event, increasing the recruitment of cytokines to accelerate their chemotactic function. Moreover, the lignin NPs played a role in the resolution of wounds, favoring the regeneration process. The results pave the way for further evaluations to exploit the wide applicability of natural (nano)polyphenols, making them extremely interesting for the medical sector, considering their biocompatibility, anti-inflammatory, and pro-healing properties.