Nano Research

Article Title

Targeted nanoparticles for the non-invasive detection of traumatic brain injury by optical imaging and fluorine magnetic resonance imaging


imaging, nanoparticles, contrast agents, magnetic resonanceimaging, brain injury, stroke


Necrosis is a form of cell death that occurs only under pathological conditionssuch as ischemic diseases and traumatic brain injury (TBI). Non-invasive imagingof the affected tissue is a key component of novel therapeutic interventions andmeasurement of treatment responses in patients. Here, we report a bimodalapproach for the detection and monitoring of TBI. PEGylated poly(lactic-coglycolicacid) (PLGA) nanoparticles (NPs), encapsulating both near infrared (NIR)fluorophores and perfluorocarbons (PFCs), were targeted to necrotic cells. Weused cyanine dyes such as IRDye 800CW, for which we have previouslydemonstrated specific targeting to intracellular proteins of cells that have lostmembrane integrity. Here, we show specific in vivo detection of necrosis by opticalimaging and fluorine magnetic resonance imaging (19F MRI) using newly designedPLGA NP(NIR700 + PFC)-PEG-800CW. Quantitative ex vivo optical imaging and19F MR spectroscopy of NIR-PFC content in injured brain regions and in majororgans were well correlated. Both modalities allowed the in vivo identificationof necrotic brain lesions in a mouse model of TBI, with optical imaging beingmore sensitive than 19F MRI. Our results confirm increased blood pool residencetime of PLGA NPs coated with a PEG layer and the successful targeting ofTBI-damaged tissue. A single PLGA NP containing NIR-PFC enables both rapidqualitative optical monitoring of the TBI state and quantitative 3D informationfrom deeper tissues on the extent of the lesion by MRI. These necrosis-targetingPLGA NPs can potentially be used for clinical diagnosis of brain injuries.

Graphical Abstract


Tsinghua University Press