Laser-Induced Fluorescence Spectroscopy in the Diagnosis of Tissue Hypoxia (Review)

Abstract

The aim of review is to discuss the results of studies on diagnosis of tissue hypoxia by laser-induced spectroscopy, as well as to identify promising trends and prospects of this technique for its further application in experimental and clinical medicine.The review presents the findings of studies of the fluorescence intensity of endogenous fluorophore molecules (reduced nicotinamide adenine dinucleotide, oxidized flavin adenine dinucleotide) as markers of ischemic injury of internal organs (brain, heart, liver, kidneys, etc.). The principles of fluorescence laser-induced spectroscopy in vivo are discussed. The historical aspects of the subject are also covered. The results of the use of the technique in experimental and clinical studies of tissue hypoxia and ischemia are shown. Difficulties in interpreting the intensity values of autofluorescent signal of the studied molecules are revealed. It was noted that the tissue autofluorescence in a long-term anoxia remains unknown, and there are no structured ideas about the impact of exogenous and endogenous factors on autofluorescence intensity.In conclusion, the use of laser-induced fluorescence spectroscopy to diagnose tissue ischemia is a promising area of experimental and clinical medicine, which still has various unresolved issues, despite a large number of studies in this domain.

Laser-Induced Spectral-Selective Autofluorescent Microscopy as a Prospective Method of Research in Biomedicine

“…It was found that this phenomenon is associated mainly with endogenous porphyrins [5]. Much more biochemical substances are emitted (luminescent) in the blue and yellow-green regions of the spectrum: reduced pyridine nucleotides (NAD-H, NADF-H), oxidized flavoproteins (FMN, FAD), vitamins, metabolic products, including pyridoxal, folic acid, its derivatives, etc [5,10].…”

“…Many studies have been conducted on the use of AF-based methods to distinguish pathological from physiological conditions in cells and tissues. A large number of methods for studying typical pathological processes based on the obtained results of AF analysis have been proposed [6][7][8][9][10][15][16][17][18][19][20][21][22][23][24][25][26]. However, despite the accumulated extensive experimental experience, this method has not yet become widespread in medical diagnostic practice, as it is necessary to address the issue of standardization of research methods.…”

“…In modern medical diagnostics, optical methods of tissue examination, called "optical biopsy", are widespread. Optical biopsy uses optical spectroscopy -absorption, fluorescence, spectroscopy of combinatorial light scattering, and methods of medical optical imaging -optical coherence tomography, confocal laser endomicroscopy [1][2][3][4][5][6][7][8][9][10]. Since the last century, technological advances in microscopy and spectrophotometry have drawn the attention of the scientific community to the fluorescence of biological tissues [7,8,10].…”

“…Optical biopsy uses optical spectroscopy -absorption, fluorescence, spectroscopy of combinatorial light scattering, and methods of medical optical imaging -optical coherence tomography, confocal laser endomicroscopy [1][2][3][4][5][6][7][8][9][10]. Since the last century, technological advances in microscopy and spectrophotometry have drawn the attention of the scientific community to the fluorescence of biological tissues [7,8,10]. In our opinion, this area of research is promising and in the coming years there will be continuous progress in the development of new devices for detecting fluorescence and interpretation of the data, as well as finding endogenous fluorophores for use as internal biomarkers.…”

“…Many areas of biophysics, molecular and cell biology, and medicine have emerged and are developing due to the introduction of new methods based on fluorescence [12]. Fluorescence microscopy in many cases is an ideal highly sensitive technique for the study of any biological samples, because it allows you to selectively and specifically detect molecules in small concentrations [4,[7][8][9][10]. the autofluorescence properties of cells and tissues, to evaluate the available instrumental systems and methods for monitoring autofluorescence and the potential for its application in the biomedical field.…”