CONICET | Buscador de Institutos y Recursos Humanos

Nanoparticles (NPs) contribute to increase the stability of certain encapsulated bioactive compounds as well as to improve its delivery into target tissues with difficulty to access. Due to the epitheliums´ permeability characteristics, their cells constitute a first physical barrier against the penetration of external substances, including NPs. Biomolecules are internalized into cells by a form of active transport called endocytosis. This process is classified into two main categories: phagocytosis and pinocytosis. The latter is subcategorized into Clathrin-mediated endocytosis, Caveolin-mediated endocytosis, and Macropinocytosis. We designed and developed NP based on high molecular weight chitosan (HCS) crosslinked with sodium tripolyphosphate (TPP). HCS has its origin in the deacetylated chitin from the processing of Argentinean prawns. NPs have a spherical shape, an average size of 144nm and a positive ζ potential (+32mV). Moreover, its time-dependent internalization in retinal pigment epithelial cells (ARPE-19) was confirmed. Next, we will explore the mechanisms of interaction between NP and cell membranes. For this purpose, ARPE-19 cells will be pre-treated with inhibitors of each endocytic pathway mentioned above (chlorpromazine, genistein, and amiloride) prior to NPs incubation at examined non-toxic concentrations. Changes in cell uptake patterns will be monitored using fluorescence microscopy. In this way, our research will contribute to the understanding of the different pathways involved in the NP entrance within ARPE-19 cells. We envision that HCS-NPs could constitute novel carriers for bioactives, opening the option for its use in ocular pharmacology.