Imaging the urinary pathways in mice by liposomal indocyanine green

Nanomedicine. 2015 Jul;11(5):1057-64. doi: 10.1016/j.nano.2015.02.019. Epub 2015 Mar 16.

Abstract

Intraoperative ureter identification can assist in the prevention of ureteral injury and consequently improve surgery outcomes. Our aim was to take advantage of the altered pharmacokinetics of liposomal indocyanine green (ICG), the only FDA-approved near-infrared (NIR) dye, for imaging of ureters during surgeries. ICG was passively adsorbed to liposomes. NIR whole mice body and isolated tissue imaging were used to study liposomal ICG properties vs. free ICG. In vivo, the urinary bladder could be clearly observed in most of the liposome-treated mice. Liposomal encapsulation of ICG enhanced ureteral emission up to 1.9 fold compared to free ICG (P<0.01). Increase in liposomal micropolarity and microviscosity and differential scanning calorimetry supported ICG localization within the liposomal bilayer. Our findings suggest that liposomal ICG could be utilized for ureteral imaging intra-operatively, thus potentially improving surgical outcomes.

From the clinical editor: Iatrogenic ureteral injury is a serious complication of abdominal surgery and intra-operative recognition of the ureters is usually the best method of injury prevention. In this article, the authors developed liposomal indocyanine green, which could be excreted via the urinary system and investigated its in-vivo use in mice.

Keywords: Abdominal surgeries; Indocyanine green; Liposomes; Near-infrared imaging; Ureters imaging.

MeSH terms

  • Animals
  • Coloring Agents / administration & dosage*
  • Coloring Agents / pharmacokinetics
  • Female
  • Indocyanine Green / administration & dosage*
  • Indocyanine Green / pharmacokinetics
  • Infrared Rays
  • Liposomes
  • Mice
  • Optical Imaging / methods*
  • Ureter / injuries
  • Ureter / pathology*
  • Urinary Bladder / injuries
  • Urinary Bladder / pathology*

Substances

  • Coloring Agents
  • Liposomes
  • Indocyanine Green