Near-IR light is ideally suited to the optical imaging of live cells and whole animals because of the lower autofluorescence, lower phototoxicity, and greater tissue penetration in this spectral region. However, there are no near-IR fluorescent proteins, and exogenous near-IR fluorophores either lack cell permeability or give rise to extensive background labeling within cells. This has greatly limited the ability to use near-IR light to image intracellular events. For example, exemplary sulfonated near-IR fluorophores such as Cy5 are not cell permeable and have been largely restricted to extracellular applications. Furthermore, near-IR fluorophores have been recalcitrant to the methods generally used to trigger the activation of fluorescence. This has limited the ability of near-IR fluorophores to report on enzymatic activity or be responsive to photoactivation. In this grant, we plan a rational and straightforward approach to 1) deliver exemplary sulfonated near-IR fluorophores into cells, 2) create photoactivatable near-IR fluorophores that can be used to study the dynamic behavior of biomolecules and cells, and 3) detect enzymatic activity in live cells using near-IR light. Together, the near-IR fluorescent tools we develop will bring the significant advantages of near-IR imaging to the study of dynamic and enzymatic processes in live cells, with major potential applications for both basic research and medical imaging.

Public Health Relevance

Live imaging of cells with light is a simple and rapid way to observe the inner workings of cell function. This study will improve the ability of light-based imaging to be used for the study and diagnosis of disease.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM087460-05
Application #
8447495
Study Section
Microscopic Imaging Study Section (MI)
Program Officer
Deatherage, James F
Project Start
2009-04-01
Project End
2014-03-31
Budget Start
2013-04-01
Budget End
2014-03-31
Support Year
5
Fiscal Year
2013
Total Cost
$295,609
Indirect Cost
$115,908
Name
University of Massachusetts Medical School Worcester
Department
Biochemistry
Type
Schools of Medicine
DUNS #
603847393
City
Worcester
State
MA
Country
United States
Zip Code
01655