Biomedical Photonics (Jan 2015)
Laser microscope-spectrum analyzer for studying intracellular accumulation of near infrared emitting photosensitizers in vitro
Abstract
Measuring system based on the binocular microscope for analysis of intracellular accumulation of infrared IR photosenstizers allowing to obtain graphic data about state of analyzed objects, location of fluorescence foci and to obtain details of spectral profile of fluorescence emission centers in IR spectral region was developed. According to image of fluorescence signal distribution the location of photosensitizer accumulation in the cell may be detected accurately and the spectrum of fluorescence signal of near IR-range in the targeted point may be obtained. The developed system is quite comprehensive because there is an opportunity to choose technical parameters, operating modes, measuring methods and analysis. The advantage of the developed microscope-spectrum analyzer is an opportunity to focus emission and create high power intensity on the irradiated area by means of laser source with small-angle beam spreading, all this allow to perform ultra-precise operations with cells. Particularly, tunable size of the diaphragm opening in the far field allows to register fluorescence signal on certain cell organoids. By means of developed system the studies of accumulation of the new bacteriochlorine photosensitizers on HeLa cell line were performed. The system allowed to register accumulation of cancer cells with definite sites of selectively accumulated photosensitizer. The sites of fluorescence were the centers of accumulation of bacteriochlorine photosensitizer, this suggests that studied photosensitizer has a tendency for local accumulation in cellular organoids. The authors suggested that the developed system allowed to perform the effective and rapid screening of new photosensitizers, particularly IR bacteriochlorine photosensitizers.
