Fabrication of indocyanine green encapsulated biodegradable microbubbles for structural and functional imaging of cancer

J Biomed Opt. 2009 May-Jun;14(3):034020. doi: 10.1117/1.3147424.

Abstract

We developed a novel dual-modal contrast agent for the structural and functional imaging of cancer. The contrast agent was fabricated by encapsulating indocyanine green (ICG) in poly(lactic-co-glycolic acid) (PLGA) microbubbles using a modified double-emulsion method. More stabilized absorption and fluorescence emission characteristics were observed for aqueous and plasma suspensions of ICG-encapsulated microbubbles. The technical feasibility of concurrent structural and functional imaging was demonstrated through a series of benchtop tests in which the aqueous suspension of ICG-encapsulated microbubbles was injected into a transparent tube embedded in an Intralipid phantom at different flow rates and concentrations. Concurrent fluorescence imaging and B-mode ultrasound imaging successfully captured the changes of microbubble flow rate and concentration with high linearity and accuracy. One potential application of the proposed ICG-encapsulated PLGA microbubbles is for the identification and characterization of peritumoral neovasculature for enhanced coregistration between tumor structural and functional boundaries in ultrasound-guided near-infrared diffuse optical tomography.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Biocompatible Materials / chemistry
  • Diagnostic Imaging / methods*
  • Indocyanine Green / chemistry*
  • Lactic Acid / chemistry*
  • Linear Models
  • Microbubbles*
  • Neoplasms / diagnosis*
  • Phantoms, Imaging
  • Polyglycolic Acid / chemistry*
  • Polylactic Acid-Polyglycolic Acid Copolymer
  • Spectrometry, Fluorescence / methods
  • Spectroscopy, Near-Infrared / methods
  • Ultrasonography / methods

Substances

  • Biocompatible Materials
  • Polylactic Acid-Polyglycolic Acid Copolymer
  • Polyglycolic Acid
  • Lactic Acid
  • Indocyanine Green