Nanoparticle-Based in Vivo Investigation on Blood−Brain Barrier Permeability Following Ischemia and Reperfusion

Abstract

The blood-brain barrier (BBB) represents a significant impediment to a large variety of central nervous system-active agents. In the current study, we applied fluorescent polystyrene nanospheres (20 nm) to study the BBB permeability following cerebral ischemia and reperfusion. A microdialysis probe was implanted in the cerebral cortex of an anesthetized rat injected with fluorescent polystyrene nanospheres. The circulating nanospheres extravasating to the brain extracellular fluids were collected by the probe. Fluorescence intensity in the microdialysates throughout the course of cerebral ischemia/reperfusion was measured. Cerebral ischemia and reperfusion induced transient accumulations of extracellular nanospheres in the brain. The accumulation of nanospheres may result from their extravasation from the blood vessels. The concurrent cerebral oxygen levels monitored using oxygen-dependent quenching of phosphorescence decreased following ischemia and returned to their original levels after reperfusion. In conclusion, we demonstrated that high temporal resolution measurements of BBB permeability in vivo can be obtained using fluorescence polystyrene nanospheres and that these data correlate with changes of cerebral oxygen concentration. This present investigation indicates that nanoparticles have potential clinical applications involving drug delivery and determination of therapeutic efficacy and on-site diagnosis.

Nanomedicine in the diagnosis and therapy of neurodegenerative disorders

“…Carboxylated polystyrene nanospheres (20 nm) were evaluated for CNS drug delivery [201]. After intravenous injection such nanospheres remained in the vasculature under normal conditions.…”

The role of peptides in blood‐brain barrier nanotechnology

“…Cerebral ischemia can cause an increase in BBB permeability, due to the up-regulation of proinflammatory cytokines. This effect can be studied by a novel approach involving in vivo microdialysis and fluorescently labelled nanoparticles [34].…”

Enhancement of Biomolecular Recognition of DTIC Based on Functional Monodisperse Polystyrene Spheres

“…[1][2][3][4][5] Although these nanoparticles have some unique optical properties, their biocompatibility is not as good as some organic polymers that could be specially utilized in some in vivo research. [6,7] Recently, nanometer-scale polymer spheres, like polystyrene nanoparticles, were synthesized and used in many biological and chemical studies.…”