Molecular imaging of neutropilin-1 receptor using photoacoustic spectroscopy in breast tumors

Keith M. Stantz, Minsong Cao, Bo Liu, Kathy D. Miller, Lili Guo

Research output: Chapter in Book/Report/Conference proceedingConference contribution

7 Scopus citations


Purpose: Our purpose is to develop and test a molecular probe that can detect the expression of neutropilin-1 receptor (NPR-1) in vivo using fluorescence imaging and photoacoustic spectroscopy. Introduction: NPR-1 is expressed on endothelial cells and some breast cancer cells, and binds to vascular endothelial growth factor VEGF165, a growth factor associated with pathological tumor angiogenesis. This receptor is coexpressed with VEGFR2 and shown to enhance the binding of VEGF165; therefore, it has the potential to be used as a marker of angiogenic activity and targeted for therapy. Material and Methods: A peptide specific to NPR-1 receptor was synthesized and conjugated to a NIR fluorochrome (IRDye800CW) and was intravenously injected into mice with breast tumors (MCF7VEGF). Probe kinetics was monitored in vivo via near infrared fluorescence (NIRF) within an optical imager for up to 72 hours within the tumor and compared to other organs (liver, muscle) for binding specificity. A multivariate fitting algorithm was used to spectrally deconvolve the IRDye800CW from endogenous hemoglobin signature (hemoglobin concentration and oxygen saturation). Results: Dynamics of the NIR fluorescence signal within the first hour after injection indicates specific binding compared to muscle, with an average tumor-to-muscle ration of 2.00 (+/- 0.27). Spectral analysis clearly indentified the presence of the NPR-1 probe. Based on calibration data, the average tumor concentration from both NIRF and PCT-S was measured to be ∼200-300nM. Conclusion: These preliminary results show the capability of PCT to image an exogenous probe in vivo in addition to its hemoglobin state.

Original languageEnglish (US)
Title of host publicationPhotons Plus Ultrasound
Subtitle of host publicationImaging and Sensing 2010
StatePublished - May 3 2010
EventPhotons Plus Ultrasound: Imaging and Sensing 2010 - San Francisco, CA, United States
Duration: Jan 24 2010Jan 26 2010

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
ISSN (Print)1605-7422


OtherPhotons Plus Ultrasound: Imaging and Sensing 2010
CountryUnited States
CitySan Francisco, CA



  • Angiogenesis
  • Breast cancer
  • Neutropilin-1 receptor
  • Photoacoustic computed tomographic spectroscopy

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Radiology Nuclear Medicine and imaging

Cite this

Stantz, K. M., Cao, M., Liu, B., Miller, K. D., & Guo, L. (2010). Molecular imaging of neutropilin-1 receptor using photoacoustic spectroscopy in breast tumors. In Photons Plus Ultrasound: Imaging and Sensing 2010 [75641O] (Progress in Biomedical Optics and Imaging - Proceedings of SPIE; Vol. 7564).