Hyperthermia of magnetic nanoparticles allows passage of sodium fluorescein and Evans blue dye across the blood–retinal barrier

AbstractPurpose: The blood–retina barrier (BRB) is a biological barrier consisting of tightly interconnected endothelial cells inside the retinal vascular network that protects the neural tissue from harmful pathogens and neurotoxic molecules circulating in the bloodstream. Unfortunately, with regard to retinoblastoma, this barrier also prevents systemically administered therapeutics reaching the retinal tissue. In this study we introduce a novel technique to locally and transiently increase BRB permeability for drug delivery using hyperthermia of magnetic nanoparticles (MNPs).Materials and methods: An alternating current (AC) magnetic field was used to induce hyperthermia of locally injected MNPs in the left ophthalmic artery of a rat model. To improve adherence on the surface of the endothelium, commercially available MNPs coated with human transferrin glycoproteins were used. After hyperthermia we assessed the extravasation of systemically injected sodium fluorescein (NaF) as well as Evans blue dye (EB...