VISUALIZING REACTIVE OXYGEN MOLECULES: To detect endogenous hydrogen peroxide in live animals, Kanyi Pu and colleagues constructed a chemiluminescent probe tucked inside a semiconducting polymer nanoparticle (SPN). The yellow cylinders denote the substrate, and the red pyramid denotes a dye that allows the probe to emit in the near-infrared range (below). The scientists tested the probe in a mouse model of neuroinflammation?(above). From left to right, the images show mice treated with saline, lipopolysaccharide alone, which causes inflammation, or lipopolysaccharide with glutathione, which abates the injury. The probe lights up to mark peroxide levels in inflamed brain tissues.ACS NANO, 10:6400-09, 2016
The ability to peer at molecular processes as they unfold in vivo can deliver invaluable insights to researchers. Molecules that shuttle through living cells are often vital biomarkers of disease conditions, and capturing tiny quantitative changes in their levels is an essential part of diagnosis in the era of precision medicine. What’s more, dynamic monitoring of physiological changes can also help track and adjust drug treatments during preclinical studies.
In order to get a bead on key molecules that signal disruptions in regular cell functions, scientists need to cast a wide net. MRI, PET, and CT imaging are useful tools to visualize and measure cellular processes, but they are vastly more expensive than light-based imaging techniques.
A variety of fluorescent probes are available to detect specific molecules and monitor their activities. But optical imaging in living animals has mostly been limited to the study of skin, eyes, surface vessels, and epithelial tissues accessible to visible light. In recent years, however, investigators have been developing probes that work in the ...
