title: New generation ICG-based contrast agents for ultrasound-switchable fluorescence imaging.
abstract: Recently, we developed a new technology, ultrasound-switchable fluorescence (USF), for high-resolution imaging in centimeter-deep tissues via fluorescence contrast. The success of USF imaging highly relies on excellent contrast agents. ICG-encapsulated poly(N-isopropylacrylamide) nanoparticles (ICG-NPs) are one of the families of the most successful near-infrared (NIR) USF contrast agents. However, the first-generation ICG-NPs have a short shelf life (<1 month). This work significantly increases the shelf life of the new-generation ICG-NPs (>6 months). In addition, we have conjugated hydroxyl or carboxyl function groups on the ICG-NPs for future molecular targeting. Finally, we have demonstrated the effect of temperature-switching threshold (Tth) and the background temperature (TBG) on the quality of USF images. We estimated that the Tthof the ICG-NPs should be controlled at ~38-40 °C (slightly above the body temperature of 37 °C) for future in vivo USF imaging. Addressing these challenges further reduces the application barriers of USF imaging.
authors: Ultrasound and Optical Imaging Laboratory, Department of Bioengineering, The University of Texas at Arlington, Arlington, TX 76019, USA.|Joint Biomedical Engineering Program, The University of Texas at Arlington and The University of Texas Southwestern Medical Center at Dallas, TX 75390, USA.
authors: Shuai
authors: S
authors: Yu
authors: Ultrasound and Optical Imaging Laboratory, Department of Bioengineering, The University of Texas at Arlington, Arlington, TX 76019, USA.|Joint Biomedical Engineering Program, The University of Texas at Arlington and The University of Texas Southwestern Medical Center at Dallas, TX 75390, USA.
authors: Bingbing
authors: B
authors: Cheng
authors: Ultrasound and Optical Imaging Laboratory, Department of Bioengineering, The University of Texas at Arlington, Arlington, TX 76019, USA.|Joint Biomedical Engineering Program, The University of Texas at Arlington and The University of Texas Southwestern Medical Center at Dallas, TX 75390, USA.
authors: Tingfeng
authors: T
authors: Yao
authors: Joint Biomedical Engineering Program, The University of Texas at Arlington and The University of Texas Southwestern Medical Center at Dallas, TX 75390, USA.|Department of Bioengineering, The University of Texas at Arlington, Arlington, TX 76019, USA.
authors: Cancan
authors: C
authors: Xu
authors: Joint Biomedical Engineering Program, The University of Texas at Arlington and The University of Texas Southwestern Medical Center at Dallas, TX 75390, USA.|Department of Bioengineering, The University of Texas at Arlington, Arlington, TX 76019, USA.
authors: Kytai T
authors: KT
authors: Nguyen
authors: Joint Biomedical Engineering Program, The University of Texas at Arlington and The University of Texas Southwestern Medical Center at Dallas, TX 75390, USA.|Department of Bioengineering, The University of Texas at Arlington, Arlington, TX 76019, USA.
authors: Yi
authors: Y
authors: Hong
authors: Ultrasound and Optical Imaging Laboratory, Department of Bioengineering, The University of Texas at Arlington, Arlington, TX 76019, USA.|Joint Biomedical Engineering Program, The University of Texas at Arlington and The University of Texas Southwestern Medical Center at Dallas, TX 75390, USA.
authors: Baohong
authors: B
authors: Yuan
mesh_terms: D000180:Acrylic Resins / Q000138:chemical synthesis / Q000494:pharmacology*; D003287:Contrast Media / Q000138:chemical synthesis / Q000494:pharmacology*; D007208:Indocyanine Green / Q000138:chemical synthesis / Q000494:pharmacology*; D053758:Nanoparticles; D061848:Optical Imaging / Q000379:methods*; D000069453:Ultrasonic Waves
chemical_list: D000180:Acrylic Resins; D003287:Contrast Media; C052970:poly-N-isopropylacrylamide; D007208:Indocyanine Green