Engineering a lifetime-based activatable probe for photoacoustic imaging

Ekaterina Morgounova; Qi Shao; Benjamin Hackel; Shai Ashkenazi

doi:10.1117/12.2004278

21 February 2013 Engineering a lifetime-based activatable probe for photoacoustic imaging

Ekaterina Morgounova, Qi Shao, Benjamin Hackel, Shai Ashkenazi

Proceedings Volume 8596, Reporters, Markers, Dyes, Nanoparticles, and Molecular Probes for Biomedical Applications V; 85960O (2013) https://doi.org/10.1117/12.2004278
Event: SPIE BiOS, 2013, San Francisco, California, United States

Abstract

High-resolution, high-penetration depth activatable probes are needed for in-vivo imaging of enzyme activity. In this paper, we will describe the contrast mechanism of a new photoacoustic activatable probe that changes its excitation lifetime upon activation. The excitation decay of methylene blue (MB), a chromophore commonly used in therapeutic and diagnostic applications, is probed by photoacoustic lifetime contrast imaging (PLCI). The monomer of the dye presents a high-quantum yield of intersystem-crossing and long lifetime (70 μs) whereas the dimer is statically quenched with a short lifetime (a few ns). This forms the basis of a highly sensitive contrast mechanism between monomers and dimers. Two dimerization models - one using sodium sulfate, the other using sodium dodecyl sulfate - were applied to control the monomer-to-dimer ratio in MB solutions. Preliminary results show that the photoacoustic signal of a dimer solution is efficiently suppressed (< 20 dB) due to their short lifetime compared to the monomer sample. Flash-photolysis of the same solutions reveals a 99% decrease in transient absorption confirming PLCI results. This contrast mechanism can be applied to design a MB dual-labeled activatable probe bound by an enzyme-specific cleavable peptide linker. When the probe is cleaved by its target, MB molecules will separate by molecular diffusion and recover their long excitation lifetime enabling their detection by PLCI. Our long-term goal is to investigate enzyme-specific imaging in small animals and establish pre-clinical data for translational research and implementation of the technology in clinical applications.

Citation Download Citation

Ekaterina Morgounova, Qi Shao, Benjamin Hackel, and Shai Ashkenazi "Engineering a lifetime-based activatable probe for photoacoustic imaging", Proc. SPIE 8596, Reporters, Markers, Dyes, Nanoparticles, and Molecular Probes for Biomedical Applications V, 85960O (21 February 2013); https://doi.org/10.1117/12.2004278

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
9 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Absorption

Tissue optics

Photoacoustic imaging

Signal detection

Photoacoustic spectroscopy

Sodium

Chromophores

Show All Keywords

Keywords/Phrases

Search In:

Publication Years