Natalia I. Afanasyeva

A Novel Mitochondrial Signaling Pathway Activated by Visible-to-near Infrared Radiation¶

Abstract The number of cells attached to glass substratum increases if HeLa cell suspension is irradiated with monochromatic visible-to-near infrared radiation before plating (the action spectrum with maxima at 619, 657, 675, 700, 740, 760, 800, 820, 840 and 860 nm). Treating of cell suspension with sodium azide (2 × 10−5 M), sodium nitroprusside (5 × 10−5 M), ouabain (1 × 10−6 M) or amiloride (1.7 × 10−5 M) before irradiation significantly modifies the spectrum of cell attachment enhancement. A light-induced mitochondrial signaling pathway can be regulated by small ligands directly binding to the catalytic center of cytochrome c oxidase (N3, NO) as well as by chemicals specifically binding to plasma membrane enzymes (ouabain, amiloride). The comparative analysis of action spectra allows the conclusions that first, CuA and CuB chromophores of cytochrome c oxidase could be involved as photoacceptors and second, various signaling pathways (reaction channels) between cytochrome c oxidase and cell attachment regulation are at work.

Fourier transform infrared evanescent wave (FTIR-FEW) spectroscopy of tissue

A new Fourier transform infrared fiberoptic evanescent wave (FTIR-FEW) spectroscopy method has been developed for tissue diagnostics in the middle infrared (MIR) wavelength range (3 to 20 micrometers). Specific novel fiberoptical chemical and biological sensors have been studied and used for spectroscopic diagnostic purposes. These nontoxic and nonhygroscopic fiber sensors are characterized by (1) low optical losses (0.05 to 0.2 dB/m at about 10 micrometer) and (2) high flexibility. Our new fiber optical devices can be utilized with standard commercially available Fourier transform spectrometers including attenuated total reflection (ATR) techniques. They are in particular ideally suited for noninvasive, fast, direct, sensitive investigations of in vivo and ex vivo medical diagnostics applications. Here we present data on IR spectra of skin tissue in vivo for various cases of melanoma and nevus in the range of 1480 - 1800 cm-1. The interpretation of the spectra of healthy and different stages of tumor and cancer skin tissue clearly indicates that this technique can be used for precancer and cancer diagnostics. This technique can be designed for real-time and on-line computer modeling and analysis of tissue changes.

Infrared fiber optic evanescent wave spectroscopy: applications in biology and medicine

A new powerful and highly sensitive technique for non-invasive biomedical diagnostics in vivo has been developed using Infrared Fiberoptic Evanescent Wave Fourier Transform Spectroscopy (FEW-FTIR). This compact and portable method allows to detect functional chemical groups and bonds via vibrational spectroscopy directly from surfaces including living tissue. Such differences and similarities in molecular structure of tissue and materials can be evaluated online. Operating in the attenuated total reflection (ATR) regime in the middle-infrared (MIR) range, the FEW-FTIR technique provides direct contact between the fiber probe and tissue for non-destructive, non-invasive, fast and remote (few meters) diagnostics and quality control of materials. This method utilizes highly flexible and extremely low loss unclad fibers, for example silver halide fibers. Applications of this method include investigations of normal skin, precancerous and cancerous conditions, monitoring of the process of aging, allergic reactions and radiation damage to the skin. This setup is suitable as well for the detection of the influence of environmental factors (sun, water, pollution, and weather) on skin surfaces. The FEW-FTIR technique is very promising also for fast histological examinations in vitro. In this review, we present recent investigations of skin, breast, lung, stomach, kidney tissues in vivo and ex vivo (during surgery) to define the areas of tumor localization. The main advantages of the FEW-FTIR technique for biomedical, clinical, and environmental applications are discussed.

FEW-FTIR spectroscopy applications and computer data processing for noninvasive skin tissue diagnostics in vivo

New applications for the Fiberoptic Evanescent Wave Fourier Transform Infrared (FEW-FTIR) method have been developed for the diagnostics of skin surfaces. Our technique allows for the detection of functional groups in the molecular structure of skin tissue noninvasively and in vivo. The FEW-FTIR spectroscopic method is direct, nondestructive, and fast. Our optical fibers for the middle infrared (MIR) range are nontoxic, nonhygroscopic, flexible, and characterized by extremely low losses. This combination of traditional FTIR spectroscopy and advanced fiber technology has enabled us to noninvasively investigate normal and cancerous skin tissue in vivo in the range of 900 to 4000 cm-1. We have developed a special software package of programs with database for the treatment of spectral data that utilizes wavelet analysis, principle component analysis (PCA), image processing, artificial neural fuzzy logic, and data fusion. These programs provide us with the ability to make base line corrections, normalize spectra, and determine peak positions from second order derivative spectra. In this study, we investigated normal, precancerous, and cancerous skin tissue in the range 1480 to 1800 cm-1 using these programs. The results of our surface analysis of skin tissue are discussed in terms of spectral parameters, DNA band assignments, and molecular structural similarities and differences.

Remote skin tissue diagnostics in vivo by fiber optic evanescent wave Fourier transform infrared (FEW-FTIR) spectroscopy

The new method of fiber-optical evanescent wave Fourier transform IR (FEW-FTIR) spectroscopy has been applied to the diagnostics of normal tissue, as well as precancerous and cancerous conditions. The FEW-FTIR technique is nondestructive and sensitive to changes of vibrational spectra in the IR region, without heating and damaging human and animal skin tissue. Therefore this method and technique is an ideal diagnostic tool for tumor and cancer characterization at an early stage of development on a molecular level. The application of fiber optic technology in the middle IR region is relatively inexpensive and can be adapted easily to any commercially available tabletop FTIR spectrometers. This method of diagnostics is fast, remote, and can be applied to many fields Noninvasive medical diagnostics of skin cancer and other skin diseases in vivo, ex vivo, and in vitro allow for the development convenient, remote clinical applications in dermatology and related fields. The spectral variations from normal to pathological skin tissue and environmental influence on skin have been measured and assigned in the regions of 850-4000 cm-1. The lipid structure changes are discussed. We are able to develop the spectral histopathology as a fast and informative tool of analysis.

Biocompatibility of polymer surfaces interacting with living tissue

The method of vibrational spectroscopy has been applied as a new tool for the biodiagnostics of polymer implants and tissue surfaces. In this study the spectral analysis of polymer implants has been accomplished by means of Fourier transform infrared spectroscopy (FTIR) to elucidate the long-term biocompatibility and quality control of biomedical materials. Surface analysis allows the determination of the specific molecular composition and structures most appropriate for long-term compatibility in humans. Important information associated with the bioinertness or bioactivity of implants has been obtained from the spectral features of the polymer material used, including the level of polymerization. Passivated surfaces of implants have also been obtained and analyzed by means of FTIR.

Numerous applications of fiber optic evanescent wave Fourier transform infrared (FEW-FTIR) spectroscopy for subsurface structural analysis

A new infrared (IR) interferometric method has been developed in conjunction with low-loss, flexible optical fibers, sensors, and probes. This combination of fiber optical sensors and Fourier Transform (FT) spectrometers can be applied to many fields, including (1) noninvasive medical diagnostics of cancer and other different diseases in vivo, (2) minimally invasive bulk diagnostics of tissue, (3) remote monitoring of tissue, chemical processes, and environment, (4) surface analysis of polymers and other materials, (5) characterization of the quality of food, pharmacological products, cosmetics, paper, and other wood-related products, as well as (6) agricultural, forensic, geological, mining, and archeological field measurements. In particular, our nondestructive, fast, compact, portable, remote and highly sensitive diagnostics tools are very promising for subsurface analysis at the molecular level without sample preparation. For example, this technique is ideal for different types of soft porous foams, rough polymers, and rock surfaces. Such surfaces, as well as living tissue, are very difficult to investigate by traditional FTIR methods. We present here FEW-FTIR spectra of polymers, banana and grapefruit peels, and living tissues detected directly at surfaces. In addition, results on the vibrational spectral analysis of normal and pathological skin tissue in the region of 850 - 4000 cm-1 are discussed.

Investigation of normal human skin tissue and acupuncture points of human skin tissue using fiberoptical FTIR spectroscopy

An innovative spectroscopic diagnostic method has been developed for investigation of different regions of normal human skin tissue. This new method is a combination of Fourier transform IR fiberoptic evanescent wave (FTIR-FEW) spectroscopy and fiber optic techniques for the middle IR (MIR) wavelength range. The fiber optical sensors we have used are characterized by low optical losses and high flexibility for remote analysis. Our fiber optical accessories and method allows for direct interaction of the skin tissue with the fiber probe and can be utilized with a diversity of standard commercial Fourier transform spectrometers. The FTIR-FEW technique, using nontoxic unclad fibers in the attenuated total reflection regime, is suitable for noninvasive, fast, sensitive investigations of normal skin in vivo for various medical diagnostics applications including studies of acupuncture points. Here we present the first data on IR spectra of skin tissue in vivo for normal skin and several acupuncture points in the range of 1300 to 1800 cm-1 and 2600 to 4000 cm-1.

Diagnostics of cancer by fiber optic evanescent wave FTIR (FEW-FTIR) spectroscopy

The fiberoptic evanescent wave Fourier transform IR spectroscopy (FEWS) using fiberoptic sensors operated in the attenuated total reflection (ATR) regime in the mid-IR region of the spectrum (4 to 16 micrometer) has recently found application in the diagnostics of biotissues. The silver halide fibers used are non-toxic, non-hygroscopic, flexible and soft and are characterized by a low optical loss. The method allows for non-invasive and rapid (seconds) direct measurements of the spectra of normal and pathological tissues in vitro, ex vivo and in vivo with the aim of express testing of various tumor tissues at the early stages of their development. The method is expected to be further developed for endoscopic and biopsy applications.

New method for investigations of normal human skin surfaces in vivo using fiber-optic evanescent wave fourier transform infrared spectroscopy (FEW-FTIR)

Fiber-optic evanescent wave Fourier transform infrared spectroscopy (FEW-FTIR) is a new method developed for different applications for surface analysis of materials, including the diagnostics of skin and living tissues. Our technique allows for the detection of inconsistencies in the molecular structure of normal skin surface non-invasively and in vivo. This FEW-FTIR method is direct, non-destructive and fast (seconds). Our optical fibers for the middle infrared (MIR) range are non-toxic, non-hygroscopic, flexible and characterized by extremely low losses. The combination of Fourier transform infrared spectroscopy and advanced fiber technology in the MIR range has opened the door for new powerful diagnostic tools for investigations of many skin surface phenomena, including normal skin, process of aging, allergies and precancerous conditions. Our method could be extended to applications involving the detection of the influence of environmental factors (sun, water, pollution and weather) on the skin surfaces of children and adults. In this study, we have investigated non-invasively more than 118 cases of normal skin in vivo in the range of 1450-1800 cm -1 . We compare the FEW-FTIR spectra of palm, hand and elbow tissue. The results of our surface analysis of skin tissue are discussed in terms of structural similarities and differences on a molecular level.