Confocal Microendoscope for In Vivo Molecular Imaging

DESCRIPTION (provided by applicant):
The objective of this research is to develop a practical effective instrument
for in-vivo microscopic imaging. The confocal microendoscope is a
catheter-based instrument that utilizes a fiber-optic imaging bundle to view
tissue at the cellular level in situ. Encouraging preliminary results have
been obtained with fluorescence imaging of tissues using a prototype confocal
microendoscope system. The primary aims of this research are to complete the
technical development of the instrument, to identify and evaluate suitable
fluorescent molecular labels, and then to evaluate clinical applications that
can exploit this technology. The technical development includes improvements
in the catheter and the confocal imaging system. The catheter of the confocal
microendoscope consists of a miniature microscope objective and focusing
mechanism attached to the distal end of a fiber-optic imaging bundle. A
specific aim of the research is to build a small and optimized catheter that
can be routed through the instrument channel of clinical endoscopes or through
small openings of the body. The development of the catheter represents a
significant technical challenge given the desired size and performance
characteristics. Improvements in the confocal system and modifications to
incorporate multispectral imaging capability are also proposed. The confocal
microendoscope can image endogenous tissue autofluorescence or fluorescence
from suitable exogenous dyes or fluorescent probes. A major aspect of the work
is to investigate the imaging properties and the clinical/scientific utility
of the fluorescent signals. Investigations of tissue autofluorescence,
disease-specific fluorescent probes, and cell-permeant vital stains are
described. The confocal microendoscope is a fundamental tool that could be
used to improve the accuracy of diagnosis or the efficacy of therapeutic
intervention. An aim of this grant is to investigate and evaluate the
potential of the instrument for imaging cancers or pre-cancerous conditions of
the colon, pancreas, esophagus, and prostate, which are applications where the
instrument could have a significant clinical impact. These studies will be
performed using ex vivo human tissues obtained from surgery and biopsy.
Successful development and demonstration of the confocal microendoscope will
lead to subsequent in vivo clinical trials.