In Vivo Imaging of Septic Encephalopathy

Abstract

Septic encephalopathy is a devastating symptom of severe sepsis. Many studies have been performed to uncover the pathophysiological mechanisms of septic encephalopathy; however, novel technical approaches are still required to overcome this complex symptom. Because patients are suffering from severe cognitive impairment, coma, or delirium, which burden not only patients but also caregivers, overcoming septic encephalopathy is still a major social problem worldwide, especially in the intensive care. Septic encephalopathy seems to be caused by cytokine invasion and/or oxidative stress into the brain, and this pathological state leads to imbalance of neurotransmitters. In addition to this pathophysiology, septic encephalopathy causes complicated symptoms (e.g., ischemic stroke, edema, and aberrant sensory function). For these pathophysiological mechanisms, electrophysiology using animal models, positron emission tomography (PET), computed tomography, and magnetic resonance imaging for septic patients has provided important clues. However, the research for septic encephalopathy is currently confronted with the difficulty of complex symptoms. To overcome this situation, in this chapter, we introduce our novel methods for in vivo imaging of septic encephalopathy using near infrared (NIR) nanoparticles, quantum dots. In addition to our recent progress, we propose a strategy for the future approach to in vivo imaging of septic encephalopathy.

Near-Infrared Emitting PbS Quantum Dots for in Vivo Fluorescence Imaging of the Thrombotic State in Septic Mouse Brain

“…The observation of blood coagulation (thrombosis) in initial melanoma metastasis in mouse lungs has been reported using bioimaging with QDs [41]. The pathophysiology of septic encephalopathy is gradually becoming possible to explain by molecular mechanisms [24,42,43]; however, the diagnosis of septic encephalopathy remains difficult to determine. NIR fluorescence imaging with highly-fluorescent PbS QDs would be useful for the study of the pathophysiology of cerebral blood vessels which induce brain dysfunction.…”

“…Sepsis causes systemic inflammatory response syndrome, a devastating condition in the whole body [22]. When septic encephalopathy occurs in the brain, the symptoms include coma, delirium, and cognitive dysfunction, and are considered important social issues to be solved in patients in intensive care and critical care units [23,24]. Although various imaging technologies (e.g., computed tomography, magnetic resonance imaging, etc.)…”