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Research and developments of laser assisted methods for translation into clinical application
Ronald SROKA, Nikolas DOMINIK, Max EISEL, Anna ESIPOVA, Christian FREYMÜLLER, Christian HECKL, Georg HENNIG, Christian HOMANN, Nicolas HOEHNE, Robert KAMMERER, Thomas KELLERER, Alexander LANG, Niklas MARKWARDT, Heike POHLA, Thomas PONGRATZ, Claus-Georg SCHMEDT, Herbert STEPP, Stephan STRÖBL, Keerthanan ULAGANATHAN, Wolfgang ZIMMERMANN, Adrian RUEHM
Front. Optoelectron.. 2017, 10 (3): 239-254.
https://doi.org/10.1007/s12200-017-0724-6
Biophotonics and laser medicine are very dynamic and continuously increasing fields ecologically as well as economically. Direct communication with medical doctors is necessary to identify specific requests and unmet needs. Information on innovative, new or renewed techniques is necessary to design medical devices for introduction into clinical application and finally to become established after positive clinical trials as well as medical approval. The long-term endurance in developing light based innovative clinical concepts and devices are described based on the Munich experience. Fluorescence technologies for laboratory medicine to improve non-invasive diagnosis or for online monitoring are described according with new approaches in improving photodynamic therapeutic aspects related to immunology. Regarding clinically related thermal laser applications, the introduction of new laser wavelengths and laser parameters showed potential in the treatment of varicose veins as well as in lithotripsy. Such directly linked research and development are possible when researchers and medical doctors perform their daily work in immediate vicinity, thus have the possibility to share their ideas in meetings by day.
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Excitation-emission matrices (EEMs) of colorectal tumors – tool for spectroscopic diagnostics of gastrointestinal neoplasia
E. BORISOVA, Ts. GENOVA, O. SEMYACHKINA-GLUSHKOVSKAYA, N. PENKOV, I. TERZIEV, B. VLADIMIROV
Front. Optoelectron.. 2017, 10 (3): 292-298.
https://doi.org/10.1007/s12200-017-0720-x
The autofluorescence spectroscopy of biological tissues is a powerful tool for non-invasive detection of tissue pathologies and evaluation of any biochemical and morphological changes arising during the lesions’ growth. To obtain a full picture of the whole set of endogenous fluorophores appearing in the gastrointestinal (GI) tumors investigated, the technique of excitation-emission matrix (EEM) development was applied in a broad spectral region, covering the ultraviolet and visible spectral ranges. We could thus address a set of diagnostically-important chromophores and their alterations during tumor development, namely, collagen, elastin, nicotinamide adenine dinucleotide (NADH), flavins, porphyrins, while hemoglobin’s absorption influence on the spectra obtained could be evaluated as well. Comparisons are presented between EEM data of normal mucosae, benign polyps and malignant carcinoma, and the origins are determined of the fluorescence signals forming these matrices.
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Microperforation of the human nail plate by radiation of erbium lasers
Andrey V. BELIKOV, Andrey N. SERGEEV, Sergey N. SMIRNOV, Anastasia D. TAVALINSKAYA
Front. Optoelectron.. 2017, 10 (3): 299-307.
https://doi.org/10.1007/s12200-017-0719-3
The nail plate forms a barrier that limits the effectiveness of drug delivery in the treatment of nail diseases and prevents the outflow of fluid in the case of subungual hematoma formation. Microperforation of the nail plate through laser radiation can increase the effectiveness of drug delivery and ensure the possibility of blood outflow. This study detected and identified the type and threshold of effects that arise from exposing the nail plate to Yb,Er:Glass (l= 1.54 µm) and Er:YLF (l= 2.81 µm) laser radiation. The rate and efficiency of nail plate ablation by the radiation of these lasers were studied. The effect of the storage time of a freshly extracted nail plate in open air on its ablation rate by Er:YLF (l=2.81 µm) laser radiation was also investigated. The impact of the Yb,Er:Glass and Er:YLF laser pulses on the nail plate caused bleaching, carbonization, ablation with microcrater formation, and microperforation. The laser energy densities WE (thresholds) required for these effects were determined. The maximum ablation rate for Yb,Er:Glass laser radiation was 8 µm/pulse at WE= 91±2 J/cm2, whereas that for Er:YLF laser radiation was 12 µm/pulse at WE= 10.5±0.5 J/cm2. The maximum ablation efficiency for Yb,Er:Glass laser radiation was 0.1 µm/mJ at WE = 10.5±0.5 J/cm2, whereas that for Er:YLF laser radiation was 4.6 µm/mJ at WE= 5.3±0.3 J/cm2. The laser ablation rate depends on the storage time and conditions of the freshly extracted nail plate. For example, when exposed to Er:YLF laser radiation, the laser ablation rate decreased by half from the initial maximum value in 96 h of air storage and returned to the initial value after 1 h of storage in distilled water.
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Characterization of irradiated nails in terms of depolarizing Mueller matrix decompositions
Sergey SAVENKOV, Alexander V. PRIEZZHEV, Yevgen OBEREMOK, Sergey SHOLOM, Ivan KOLOMIETS
Front. Optoelectron.. 2017, 10 (3): 308-316.
https://doi.org/10.1007/s12200-017-0727-3
Mueller matrices were measured for natural (or reference) samples of human nails and samples irradiated by a 2 Gy ionizing radiation dose. The elements of the total Mueller matrix as a function of scattering angle were measured in backscattering mode at a wavelength of 632.8 nm. Several types of depolarizing Mueller matrix decompositions, namely, Ossikovsky, Williams, and Chipman, were calculated as a function of scattering angle for each nail sample. A comparative analysis of the sensitivity of the Mueller matrix decompositions in relation to the problem of emergency dose assessment in nails was performed.
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Dynamic influence of pentoxifylline on the oxygen status of Pliss’s lymph sarcoma in rat
Tatiana I. KALGANOVA, Anna G. ORLOVA, German Yu. GOLUBYATNIKOV, Anna V. MASLENNIKOVA, Ilya V. TURCHIN
Front. Optoelectron.. 2017, 10 (3): 317-322.
https://doi.org/10.1007/s12200-017-0725-5
Tumor oxygenation is one of the key factors influencing disease prognosis and the effectiveness of treatment. Assessment of tumor oxygenation levels facilitates the selection of optimum conditions for radiation therapy, and plays an important role in creating alternative regimes of irradiation. Treating tumors with agents capable of increasing tumor oxygenation in order to increase radiosensitivity is a promising avenue of enquiry. Diffuse optical spectroscopy (DOS) allows a noninvasive determination of tissue oxygen levels based on information about the local changes in optical parameters, and the visualization of metabolic processes in the region of interest. DOS allows reconstruction of the two-dimensional distribution of main tissue chromophores that characterize the processes of oxygen supply (oxygenated hemoglobin) and oxygen consumption (deoxygenated hemoglobin), as well as the blood oxygen saturation levels, which indirectly reflect the tissue oxygenation levels. In the present study, a hemorheologic drug, pentoxifylline, which can improve microcirculation in regions with circulatory disturbances, was used for modifying tumor tissue oxygenation. Pliss’s lymph sarcoma (PLS), which is characterized by rapid growth and early occurrence of necrotic areas, was chosen as a tumor model. Tumor oxygenation was monitored by DOS with parallel plane geometry. Pentoxifylline could improve tumor oxygenation by increasing the concentration of oxyhemoglobin. The increased blood oxygen saturation persisted from 30 to 120 min after drug administration. Normal healthy tissue (muscle) and tumor tissue responded differently to the drug. DOS can be used for testing new agents that influence tissue oxygen status and blood-filling rate.
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13 articles
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