Molecular mechanisms of photochemotherapy (Review)

Mechanisms of photophysical, photobiological, and therapeutic action of light on blood in vivo are discussed based on results of spectral and clinical studies of blood, plasma, and erythrocytes. Spectral manifestations of photochemical reactions initiated in blood by therapeutic doses of radiation in vivo with light of different wavelengths are considered. Spectral and clinical results of blood investigations are compared for patients whose complex treatment included intravenous blood irradiation and magnetotherapy. Mechanisms for secondary (dark) reactions induced by the action of light on blood in vivo are discussed. The radiation of laser and non-laser light sources used at present for intravenous blood irradiation (365, 405, 450, 530, 632, 635, 808 nm) is shown to fall within hemoglobin absorption bands. The conclusion is made that blood absorption of laser and non-laser light radiation results in functional alteration of hemoglobin as a possible primary photoacceptor absorbing light radiation of the above wavelengths. The therapeutic effect of intravenous blood irradiation is initiated by hemoglobin functional activity modulation. Phototherapy is a means to correct it. Intravenous phototherapy should be considered as a therapeutic method that changes (provided that the dosage is correct) the balance of active oxygen species production and their inhibition by antioxidants. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 76, No. 1, pp. 51–75, January–February, 2009.     

Effect of intravenous laser irradiation on the molecular structure of blood and blood components

We present the results of a spectral study of the effect of low-intensity laser radiation on the molecular structure of blood and blood components. Analysis of the Fourier transform IR absorption spectra of blood confirmed the changes we observed previously in the oxygen transport characteristics of blood with intravenous exposure to the emission from a He-Ne laser. We show that structural and conformational changes in the hemoglobin tetramer, initiated by laser-induced photoreactions between Hb and oxygen, lead to characteristic changes in the shape and intensity of the IR bands for NH stretching vibrations, and also the amide I and amide II absorption bands. In the IR spectra of irradiated blood samples, we note increased absorption in the bands for stretching vibrations of the phosphate groups (945–1280 cm⁻¹), which is evidence for an increase in the nucleic acid content (DNA, RNA). In the spectra of plasma and erythrocytes prepared from irradiated blood, there are no changes in this region of the IR spectrum. At the same time, in the IR spectra of samples of irradiated plasma, the intensity of the bands for stretching vibrations of the CH₂ groups increases substantially. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 1, pp. 106–112, January–February, 2006.     

Spectral studies of photomodification of blood by therapeutic doses of optical radiation at different wavelengths

We analyze changes in electronic and IR absorption spectra of samples of blood and its components, in the fluorescence spectra of plasma, as well as in the gas composition of blood, the hemoglobin concentration, and acid-base balance indices, upon the irradiation of blood by therapeutic doses of optical radiation at 254, 632.8, 670, and 806 nm. We show that the irradiation of blood by radiation at these wavelengths initiates similar molecular changes in blood and its components and that monochromatic incoherent light acts equally as efficiently as laser radiation. We find that, if the blood irradiation wavelength is in the range of the absorption bands of hemoglobin, the hemoglobin acts as a primary photoacceptor and that the dissociation of hemoglobin complexes with ligands directly in erythrocytes is a primary photoprocess. We conclude that the photomodification of blood should be attributed to therapeutic methods capable of controlling the balance between the production of active forms of oxygen and their inhibition by antioxidant systems of the organism.     

Effect of <Emphasis Type="Italic">in vivo</Emphasis> irradiation of blood by low-intensity emission from a He–Ne laser on molecular components of blood

We have used the IR absorption spectra of blood, plasma, and packed erythrocytes to study the effect of in vivo exposure of blood to low-intensity emission from a He–Ne laser (λ = 632.8 nm, 4 mW/cm²) on the molecular components of blood. In comparing the IR spectra of samples of blood sample and blood components before and after irradiation, we identified changes in the amide A, amide I, amide II, amide III absorption regions and also in the absorption bands of methyl, methylene, and phosphate groups. We conclude that exposure of blood in vivo to emission from a He–Ne laser leads to a decrease in the contribution of the α-helix conformation in the secondary structure of the blood proteins.     

Spectral characteristics of blood irradiated in vivo by therapeutic doses of ultraviolet radiation

The influence of therapeutic doses of UV radiation (λ = 254 nm) on spectral characteristics of blood irradiated in vivo has been studied. A comparative analysis of the electronic and IR absorption spectra of blood and its components before and after irradiation, as well as of the gas composition and concentration of blood hemoglobins, revealed that phototransformations of hemoglobins are primary mechanisms of photoreactions in blood UV irradiated in vivo.     

Effect of a low-frequency magnetic field on the structure of globular blood proteins

We used IR Fourier absorption spectra of blood to study changes in the structure of globular blood proteins with extracorporeal autohemomagnetotherapy, used to treat ischemic heart disease. We compare the spectra of blood before and after magnetotherapy in the regions: amide I (1655 cm⁻¹), amide II (1545 cm⁻¹), amide III (1230–1350 cm⁻¹), amide IV and amide V (400–700 cm⁻¹). We have shown that pronounced changes in the spectra in the indicated regions on direct exposure of blood in vivo to a low-frequency pulsed magnetic field are connected with conformational changes in the secondary structure of globular blood proteins, which are apparent in the increase in the contribution of the α-helix conformation. We discuss the magnetotherapy-initiated appearance of new IR absorption bands at 1018 and 1038 cm⁻¹ and an increase in the intensity of a number of other bands located in the 1000–1200 cm⁻¹ region, which suggests a change in the concentration of some blood components. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 5, pp. 665–669, September–October, 2007.     

UV–visible,infrared absorption spectra of undoped and TiO2-doped lead phosphate glasses and the effect of gamma irradiation

Undoped and TiO₂-doped lead phosphate glasses were prepared. Ultraviolet (UV)–visible and Fourier transform-infrared (IR) absorption spectra of the prepared samples were measured before and after being subjected to doses of 30 and 60 kGy of gamma irradiation. The parent undoped lead phosphate glass reveals charge transfer UV absorption bands which are attributed to the presence of unavoidable iron impurities contaminated within the raw materials used for the preparation of the glasses and the sharing of divalent lead (Pb²⁺) ions. Experimental spectral data indicate that the doped titanium ions are involved in such glasses in two valences, namely the trivalent and tetravalent states. The predominant trivalent titanium (Ti³⁺) ions are characterized by its purple color and exhibiting two visible absorption bands at about 500–550 and 700–720 nm. The lesser tetravalent titanium (Ti⁴⁺) ions belong to the d⁰ configuration and generally exhibit only an UV absorption band. Spectral data show that gamma irradiation causes noticeable changes in the undoped and TiO₂-doped samples in the UV range while the effects are limited in the visible range. The observed changes in the UV region are attributed to photochemical reactions while TiO₂-doped samples show retardation or shielding toward continuous gamma irradiation together with the sharing of heavy Pb²⁺ ions. IR absorption spectra reveal the vibrations of several phosphate groups including the metaphosphate chains as the main structural building units together with the possible Pb?O vibrations.     

Relationship between the Structure and Photostability of Decahydroacridine Derivatives

The absorption and photoluminescence spectra of a number of derivatives of 3,3,6,6-tetramethyl-N-phenyl-decahydroacridine-1,8-dione with a regular change in the structure of molecules are investigated. Their electronic structure is calculated. The nature of some of the spectral bands is established. Significant differences in the efficiency of the processes of photochemical transformations of dyes exposed to UV irradiation have been revealed; these changes are attributable to the different donor-acceptor properties of the substituents introduced. A mechanism of phototransformations that agrees with both calculations of the electronic structure of molecules and the spectral-luminescent characteristics of the initial and irradiated compounds is suggested. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 4, pp. 454–459, July–August, 2005.     

Interaction of Low-Intensity Laser Radiation with Blood and Its Components

The response of the blood of rabbits to the intravenous irradiation by a He-Ne laser radiation (λ = 632.8 nm) has been investigated by the UV-visible and IR absorption spectra of the whole blood, plasma, and erythrocyte mass. It has been established that hemoglobin is a primary photoacceptor absorbing low-intensity He-Ne-laser radiation. The exposure of blood to this radiation causes clearly defined changes in the IR and visible absorption spectra of the blood and erythrocytes. These spectral changes arise as a result of partial photodissociation of hemoglobin-ligand complexes in the process of absorption of laser radiation. It is suggested that photodissociation is a primary reaction that arises in blood exposed to a low-intensity laser radiation.__________Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 2, pp. 230–235, March–April, 2005.     

Fluorescence spectra of blood plasma treated with ultraviolet irradiation <Emphasis Type="Italic">in vivo</Emphasis>

We have studied the fluorescence spectra of blood plasma from patients with acute coronary syndrome, and also the effect of therapeutic doses of in vivo ultraviolet blood irradiation (UBI) on the spectra. We have established that the maxima in the fluorescence spectra of the original plasma samples, obtained from unirradiated blood, are located in the wavelength interval 330–340 nm, characteristic for the fluorescence of tryptophan residues. In extracorporeal UBI (λ = 254 nm), we observed changes in the shape and also both a blue and a red shift in the maxima of the fluorescence spectra, differing in magnitude for blood plasma samples from different patients in the test group. We show that UBI-initiated changes in the fluorescence spectra of the plasma depend on the original pathological disturbances of metabolite levels, and also on the change in the oxygen-transport function of the blood and the acid–base balance, affecting the oxidative stability of the plasma. We have concluded that UV irradiation, activating buffer systems in the blood, has an effect on the universal and specific interactions of the tryptophan residue with the amino acid residues and water surrounding it.     

Change in the absorption spectra of blood exposed to a low-frequency magnetic field

We have used the absorption spectra of whole blood in the UV-visible and IR regions of the spectrum to study changes in the structure of the molecular components of blood when exposed to a low-frequency pulsed magnetic field used to treat ischemic heart disease. We show that pronounced changes in the spectra when the blood is directly exposed in vivo to a magnetic field may be due to breaking of the bond between the heme group and the protein of the hemoglobin, as a consequence of changes in the intermolecular interactions in the polypeptide chains of the hemoglobin and also the spin states of the paramagnetic heme components. Exposure to a magnetic field results in changes in the conformations of the polypeptide chains of hemoglobin and the rate of dissociation of oxyhemoglobin. The structural changes in the hemoglobin molecule are considered as one of the possible primary mechanisms of action on blood in vivo for a low-frequency pulsed magnetic field. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 2, pp. 199–204, March–April, 2007.     

Degradation of white anodic-oxide coatings in UV irradiation in vacuum

Photostimulated degradation of the reflectivity of white anodic-oxide coatings on Al alloy (Al-AOCs) that are used as thermal-regulating coatings of space vehicles is investigated by spectroscopy of diffuse reflection in the region of 0.5–6 eV. It is established that irradiation in vaccum when λ≤300 nm leads to the appearance in diffuse-reflection spectra of the absorption bands at 4.0 and ∼4.6 eV that are similar to these induced by vacuum heating for T≥350 K. A growth in the absorption bands is accompanied by gas release from the coatings. These processes have a common excitation spectrum, basic kinetic regularities, and a thermoactivated character. UV irradiation in vacuum is assumed to initiate Al-AOC destruction with the formation of color centers. This process is accompanied by the desorption of molecular products. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 6, pp. 801–806, November–December, 1997.     

Degradation of the reflectivity of white anodic-oxide coatings in thermal vacuum treatment

Using the spectroscopic method of diffuse reflection in the region between 0.5 and 6 eV, we investigate the degradation of reflectivity in thermal vacuum treatment of white anodic-oxide coatings on an Al alloy (Al–AOC) that are used as thermoregulating coatings of space vehicles. It is established that at T≥350 K absorption bands at 4.05 and ∼4.7 eV resembling those induced by UV irradiation in vacuum appear in the diffuse reflection spectra of Al–AOC. The kinetics of the increase of absorption in heating Al–AOC with a constant rate correlates with the rate of gas liberation from specimens. We assume that a thermally activated reaction with the formation of color centers identical to those produced by the photoeffect occur in Al–AOC in vacuum at T≥350 K. This process is accompanied by desorption of molecular products. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 5, pp. 664–667, September–October, 1997.     

The effect of electron irradiation on the optical properties of the natural armenian zeolite-clinoptilolite

Infrared (IR) absorption and luminescence in chemically and radiation-modified natural Armenian Zeolite (clinoptilolite) samples have been studied. The luminescence was studied in 390–450 nm and 620–710 nm wavelength bands, and the IR measurements were carried out in the 400–5400 cm⁻¹ range. It is shown that the luminescence intensity depends on the content of pure clinoptilolite in the samples and, probably on the distribution of “passive” luminescence centers over Si and Al sites that became “active” under radiation or chemical treatment. The samples of electron irradiated clinoptilolite have higher luminescence intensity than the chemically and thermally treated ones. A decrease in the intensity of IR absorption bands at 3550 cm⁻¹ and 3650 cm⁻¹ was found after irradiation.     

Structure and photochromic properties of poly(vinylalcohol)/phosphotungstic acid nanocomposite films

Poly(vinylalcohol)/phosphotungstic acid (PVA/PWA) nanocomposite films were studied using Fourier-transform infrared and electron absorption spectroscopy. It was found that entrapping PWA into PVA leads to the formation of hydrogen bonds between OH groups of PVA and bridging oxygen atoms of PWA. Terminal oxygen atoms of PWA do not participate in hydrogen-bonding interactions with the polymer. Exposure of the nanocomposite film to UV radiation results both in the photo-induced transfer of protons from PVA to PWA with their attachment to the bridging oxygen atoms of PWA and in the formation of a PVA–PWA complex with the participation of deprotonated oxygen atoms of PVA and the terminal oxygen atoms of PWA. The UV irradiation causes the films to turn blue and a band of d–d transitions of W⁵⁺ ions (480 nm) and two bands of intervalence W⁵⁺ → W6+ charge-transfer transitions (740 and 1250 nm) to appear in their electronic spectrum.     

Methods for fine-tuning frequencies of absorption of actinide complexes to frequencies of laser generation lines

On the basis of analysis of relationships relating, among themselves, the positions of bands in the spectra of electron and IR absorption of uranyl complexes in solutions and the donor ability of neutral ligands, the possibility is shown for fine-tuning frequencies of absorption of complexes to frequencies of argon- and CO₂-laser generation lines and using them in the development of methods of control over chemical reactions involving actinides. Belarusian State University, 4, F. Skorina Ave., Minsk, 220050, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 3, pp. 420–422, May–June, 1999.     

Trends in the spectral distribution of the absorption coefficient of complex organic molecules

General trends in formation of the observed vibrational spectra are analyzed by calculating spectral distributions of the absorption coefficient in the IR region for 45 molecules of different classes ignoring the electrooptical paramaters of particular bonds and structural groups. It is shown that for many molecules, only vibrations of peripheral X-H bonds make a prevailing contribution to the total integral absorption in a wide spectral range. The effect of increasing intensities of some bands is clearly observed for skeleton vibrations, when optical parameters of external X-H bonds are zero. V. I. Vernadski Institute of Geochemistry and Analytical Chemistry of the Russian Academy of Sciences, 19, Kosygin St., Moscow, 117975, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 4, pp. 491–496, July–August, 1998.     

Calculation of polarized IR absorption spectra for trans-1,4-polyisoprenes of various conformations

Polarized IR spectra for two conformations of trans-1,4-polyisoprene (α-and β-gutta-percha) were calculated. The IR dichroism of the absorption bands was calculated for both conformations. The computed results for polarized IR spectra and IR dichroism agree reasonably well with the respective experiment data. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 4, pp. 470–475, July–August, 2008.     

Molar coefficients of extinction for IR absorption bands of Ni(II) acetylacetonate, ketoiminate, and trifluoroacetylacetonate

We have studied IR absorption spectra (within the spectral range of 4000-200 cm⁻¹ of the intracomplex chelate compounds Ni(II) bis-acetylacetonate, Ni(II) bis-ketoiminate, and Ni(II) bis-trifluoroacetylacetonate and have given a full interpretation and comparison of the spectra of these compounds in dissolved and solid states. The reasons for the differences in the spectra are discussed. The molar coefficients of extinction for the absorption bands are calculated. Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, 3, Akad. Lavrent’ev Ave., Novosibirsk, 630090, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 5, pp. 775–780, September–October, 1998.     

Simulation of the influence of the polymer conformation,orientation, crystallinity,and stretching on its IR absorption spectrum

Using cis-1,4-polyisoprene as an example, the influence of the conformation and orientation of the polymer chain on its polarization absorption spectra has been simulated. It has been shown that if a change in the orientation of the polymer chain leads to a monotonic change in the intensities of the absorption bands with their maxima positions remaining unchanged, then changes in the polymer chain conformation additionally cause a shift and the appearance of new absorption bands. According to the results of the calculation of the vibrational spectra, the inversion of the IR dichroism of the absorption bands of polymers is associated with the conformation transition. We simulate the influence on the IR absorption spectrum of the degree of crystallinity of cis-1,4-polyisoprene, in which the amorphous and amorphous-crystalline states are considered as a mixture of noninteracting polymer chains, where each state is characterized by a certain ratio of conformers. Likewise, the changes in the IR absorption spectrum of cis-1,4-polyisoprene under its stretching have been investigated. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 6, pp. 727–733, November–December, 2005.