• polydopamine
• nanoparticles
• antioxidant
• neurodegenerative
• arsacs
• ros
• blood-brain barrier

This work is focused on investigating the therapeutic effect of antioxidant polydopamine nanoparticles (PDNPs) for the treatment of autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS), a neurodegenerative disease caused by a mutation in the SACS gene which codes for sacsin, a protein involved in mitochondrial dynamics. The first step was the synthesis of PDNPs and their characterization in terms of morphology, hydrodynamic diameter and z-potential, then they have been functionalized with a peptide belonging to Angiopep-2 (Ang2), known for its ability to cross blood-brain barrier (BBB) with a receptor-mediated transport mechanism. PDNPs have been tested on three different cell types that are part of the BBB, that is endothelial cells (bEnd.3), astrocytes (C8D1A) and microglial cells. A series of viability and internalization assays (live/dead, Quant-iT™ PicoGreen® dsDNA Assay Kit, staining, cytofluorometry, confocal microscopy) were made. At the same time, a series of assays to evaluate antioxidant activity (CellROX® assay), apoptosis/necrosis (annexin/propidium iodide assay) and mitochondrial effects (rhodamine staining to evaluate mitochondrial morphology and membrane potential) were carried out. Two different static and dynamic BBB in vitro models were used to test the capacity of PDNPs to cross the BBB: the static model was based on a transwell with endothelial cells and astrocytes put on opposite sides of the artificial membrane, while the dynamic one involved the same cell types but adding a flow to simulate the shear stress from the blood.