Mapping microbubble viscosity using fluorescence lifetime imaging of molecular rotors

• DOI: 10.1073/pnas.1301479110
• Publication Date: 2013-05-21T05:03:59Z
• Authors: Neveen A. Hosny; Graciela Mohamedi; Paul Rademeyer; Joshua Owen; Yilei Wu; Meng-Xing Tang; Robert J. Eckersley; Eleanor Stride; Marina K. Kuimova
• Keywords: Fluorescence-lifetime imaging microscopy; Characterization; Molecular Imaging

Encapsulated microbubbles are well established as highly effective contrast agents for ultrasound imaging. There remain, however, some significant challenges to fully realize the potential of in advanced applications such perfusion mapping, targeted drug delivery, and gene therapy. A key requirement is accurate characterization viscoelastic surface properties microbubbles, but methods independent, nondestructive quantification mapping these currently lacking. We present here a strategy performing measurements that uses small fluorophore termed “molecular rotor” embedded microbubble surface, whose fluorescence lifetime directly related viscosity its surroundings. apply imaging show shell viscosities vary widely across population influenced by composition manufacturing process. also demonstrate heterogeneous distributions exist within individual shells even with single surfactant component.