Low-intensity Laser Radiation Research Articles

The Radioprotective Effects of Low-Intensity Laser Radiation on Rat Peripheral Blood Cells

Abstract—The radioprotective effect of low-intensity laser radiation on blood cells was studied on Wistar rats. The following procedures was carried out: single total body γ-radiation (dose of 3 Gy) of rats; over-vein irradiation with continuous laser radiation (λ = 670 nm); and combined γ- and laser irradiation, which varied among different series of experiments according to the number of procedures and the energy density of the laser radiation (2.5 J/cm2, 1.25 J/cm2). The influence of γ- and laser radiation on the number of peripheral blood cells in rats, the activity of antioxidant defense enzymes (superoxide dismutase and catalase), and on the blood absorption spectra in regions sensitive to its oxygenation were studied. On the 4th day after γ-irradiation, the radioprotective effect of low-intensity laser radiation was manifested as an increase in the average number of leukocytes (up to 1.4 times) and lymphocytes (up to 1.8 times) in comparison with reduced γ-irradiation, in an increase in the relative lymphocyte proportion in the leukocyte population (up to 1.5 times), and in an increase in the activities of catalase and superoxide dismutase, which were decreased by the γ-irradiation. It was found that the changes in the number of erythrocytes, leukocytes, lymphocytes, and superoxide dismutase activity initiated by γ-radiation alone and by combined laser and γ-radiation differed in individual rats and depended on individual initial values. The molecular mechanisms of the observed photo-radiobiological effects are discussed.

Low-intensive Laser Therapy for Management of Cerebral Dysfunction in Patients with Obstructive Jaundice of Non-tumor Origin

BACKGROUND The liver’s function is impaired above all others in the mechanical jaundice, which leads to the progression of endogenous intoxication and the damage of different organs and systems, including the brain. The development of hepatic encephalopathy undoubtedly aggravates the course of the disease, which requires its timely management.AIM OF STuDy: to evaluate the effcacy of the low-intensity laser therapy when managing the cerebral dysfunction in mechanical jaundice of non-tumor origin.MATERIAL AND METHODS A comprehensive study of 60 patients with obstructive jaundice of non-tumor origin was performed. The patients were divided into 2 groups: I (comparison) — the standard therapy (n=30); II (studied) group — inclusion of low-intensity laser irradiation of blood (n=30). On check dates (day 1 and 7), the severity of cerebral dysfunction was assessed in all patients using the psychometric tests (“Point in Circle, “Labyrinth”). The microcirculation was assessed with LACC 02 device (Russia). The coagulation/lysis system of blood was studied with TEG 5000 thrombelastograph (USA).RESULTS In patients with obstructive jaundice, disorders of the functional state of the liver were noted, which resulted in the growth of total bilirubin, alanine and aspartic aminotransferases, and toxic products. All this was accompanied by cerebral dysfunction, which was shown by results of the psychometric study and extended performance of tests, in particular (“Point in Circle”, “Labyrinth”). Signifcant changes and disorders of the hemostatic system were revealed in patients. The complex treatment of obstructive jaundice, which included laser therapy, allowed a relatively rapid recovery of the functional state of the brain to be observed, as evidenced by the shortening of the test time for the tests being studied. The positive effect of this kind of therapy was accompanied by a decrease in the severity of the syndrome of endogenous intoxication, improved microcirculation and hemostasis.CONCLUSION The presence of pancreatic obstructive jaundice lead to the development of florid syndrome of endogenous intoxication, which was reflected in the growth of ALT, AST, amylase, and total bilirubin. During the entire period of the study, a decrease in studied blood parameters was observed in patients who had underwent low-intensity laser therapy sessions. Conducting a psychometric study in the initial periods revealed some violations, such as extended performance of tests (“Point in Circle”, “Labyrinth”).

Biostimulating Effect of 685 nm Low‐Intensity Laser Radiation on Cell Viability in Multicellular Spheroids Culture

Recent research evidences substantial morphological and physiological differences between cells maintained in vitro in two‐dimensional (2D) and three‐dimensional (3D) culture conditions. The current consensus is that 3D culture is better because it precisely mimics the cellular microenvironment in vivo. The biomodulatory effect of low‐intensity laser radiation (LILR) on cells in 2D cultures is already well established. On the other hand, the effect of this radiation on cells in 3D cultures has not yet been widely investigated. The aim of this work was to analyze the biomodulatory effect of LILR, at the wavelength (ƛ) of 685 nm, on the viability of osteogenic precursor cells (OPC) cultured as multicellular spheroids (MS). Agarose molds containning wells (300 μm diameter) were used for MS formation using the non‐adherent surface culture concept. A cell count (2×105) of the OPC lineage (MC3T3) was seeded in each mold and maintained under ideal growth conditions (Dulbecco's Modified Eagle Medium supplemented with 10% fetal bovine serum/37°C/95% humidified atmospheric air/5% CO2). The molds were irradiated for 5 consecutive days at doses of 0.5, 1.0 or 1.5 J/cm2 (triplicates), and the first irradiation was performed immediately after seeding. After this period, the cultures were submitted to cell viability assay and the results were expressed as a percentage of non‐irradiated control cultures (ANOVA ONE‐WAY, p≤0.05). The results showed that LILR, at ƛ 685 nm, provided a 79% increase in cell viability at the dose of 1J/cm2. The remaining doses exhibited similar viability rates that the control. These results confirm the dose‐dependent biostimulatory effect of LILR at ƛ 685 nm on MS culture and contribute to the understanding of the real influence of this radiation on cells under ideal conditions for in vitro simulation studies.Support or Funding InformationCoordenação de Aperfeiçoamento de Pessoal de Nível Superior ‐ CAPES ‐ BrazilThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Application of Plasmon-Induced Lithography for Creation of a Residual-Free Pattern and Simple Surface Modifications.

Here, we propose a plasmon-induced redistribution of a thin polymer layer as a unique way for a residual layer-free lithographic approach. In particular, we demonstrate an ultrafast area-selective fabrication method using a low-intensity visible laser irradiation to direct the polymer mass flow, under the plasmon-active substrates. Plasmon-supported substrates were created by thermal annealing of Ag thin films and covered by thin polystyrene layers. Then, laser beam writing (LBW) was applied to introduce a surface tension gradient through the local plasmon heating. As a result, polystyrene was completely removed from the irradiated place, without any residual layer. The proposed approach does not require any additional development steps, such as solvent or plasma treatment. To demonstrate the advantages of the proposed technique, we implemented the LBW-patterned structures for further spatially selective surface functionalization, including the metal deposition, spontaneous thiol grafting, and electrochemical deposition of ordered polypyrrole array.

INFLUENCE OF LASER TREATMENT ON INDICATORS OF FREE-RADICAL OXIDATION AND ANTIOXIDANT PROTECTION IN SECONDARY PYELONEPHRITIS

Relevance. Optimization of the conservative tactics of acute inflammation of the kidney in nephrolithiasis makes it advisable to use non-traditional methods of detoxification low-intensity laser radiation (LILR) in particular. Aim. To evaluate the effectiveness of laser therapy (LT) in the complex correction of acute secondary pyelonephritis (ASP) in patients with single kidney stones according to the basic adaptation criteria of oxidative-antioxidant clinical medicine КЛИНИЧЕСКАЯ МЕДИЦИНА homeostasis of the organism. Materials and methods. Indices of endogenous intoxication (EI), characterizing the oxidative-antioxidant homeostasis of the body in ASP, were studied in 96 patients with nephrolithiasis aged 19 to 40 years. Patients of the comparison group (48 people) underwent basic (according to the standards) treatment aimed at controlling of calculous pyelonephritis. Patients of the main group (48 people) in the traditional conservative therapy from the second day of hospitalization daily received additional LT sessions with apparatus LTA “Uzor-3KS” with a frequency of 0.6 kHz, a power of 1.5 watts within 4 minutes (total for treatment course is eight procedures). The effectiveness of therapy was assessed on the 5th and 9th day of the inpatient stay. Results. It was found that endotoxicosis in non-destructive forms of ASP is caused by the increase in the concentration of malonic dialdehyde of plasma (by 20.3%) and erythrocytes (by 35.5%), decrease in catalase activity (by 14.2%) and the amount of total (by 11.8%) and free (21.1%) thiol groups with a decrease in the detoxification index (DI) by 24,1%. Compared with the baseline therapy (BT), the effectiveness of LT in the complex treatment of ASP in the analyzed parameters of metabolic homeostasis against the background of the increase in catalase capacity from 6.9 to 10.2%, the detoxification index from 5 to 12.5% was 7.5% (on the 5th day) and 17.5% (on the 9th day of treatment). Conclusions. ASP leads to activation of ROS, suppression of antioxidant and catalase activity of blood, reduction of DI, indicating a subcompensated syndrome of EI. Standard therapy contributes to the normalization of ROS and SLA values of body protection and reduces the level of endotoxicosis caused by ASP. Additional inclusion in the complex treatment of LT sessions more significantly normalizes redox metabolic homeostasis and EI parameters, improving the effectiveness of basic therapy.

К 90-летию со дня рождения профессора А.Л. Гущи

In the article devoted to the 90th anniversary of the birth of Professor, Honored Scientist of the RSFSR Anatoly Leonovich Gushcha, he briefly describes the main stages of his life and work, achievements and contribution to the development of the Department of Hospital Surgery of the Ryazan Medical Institute and surgery in general. Under his leadership, the department actively developed the issues of endoscopic diagnostics and surgery, x-ray studies, extracorporeal methods of detoxification, treatment of purulent-destructive diseases, the use of low-intensity laser radiation and other advanced technologies in surgery. Reconstructive operations on the biliary tract, pancreas, esophagus, gastric passage, stomach and many others were improved. Also, the professor was engaged in educational activities and wrote a number of methodical manuals on all program questions of surgery, as well as over 180 scientific papers. Under the guidance of the professor eight doctoral and 15 candidate dissertations were prepared. Five of his students have the title of professor. Anatoly Leonovich conducted a great deal of public work. For 10 years he headed the department of postgraduate and residency, he was the chairman of the board of the Regional Society of Surgeons, a board member of the All-Russian and All-Union Society of Surgeons. He was awarded the Order of the Badge of Honor, the Order of Friendship, the badges of the Honored Health Career and the Higher School of the USSR, the diploma of the Ryazan Regional Executive Committee and the Minister of Health of the USSR in 1997 he was awarded the honorary title «Honored Worker of Science of the Russian Federation». His work left a mark not only in the history of surgery, but also in the memory of his students and many grateful patients.

Photobiomodulation Therapy in Cancer Patients with Mucositis: A Clinical Evaluation

Objective: To evaluate the use of photobiomodulation therapy (PBM-T) in patients undergoing chemotherapy and/or radiotherapy and affected by oral mucositis (OM). Background: Few clinical studies have evaluated PBM-T, particularly in combination with photodynamic therapy (PDT), for the treatment of OM. Methods: Thirty-one patients were divided by convenience into two groups. One received PBM-T (n = 17) alone, consisting of low-intensity laser (LIL) irradiation (wavelength 660 nm, continuous mode, spot energy 4 J, energy density 142 J/cm2, irradiation time 40 s per spot), once weekly for 4 weeks. The other (n = 14) received a combination of PBM-T and PDT, with curcumin as photosensitizer. Patients were instructed to rinse their mouth with 20 mL of curcumin solution for 5 min. The oral cavity was irradiated with a blue light-emitting diode (power 1200 mV, wavelength 468 nm) for 5 min. LIL was applied as in the PBM-T group. After treatment, OM severity was reassessed. The results were analyzed by the Wilcoxon and Mann-Whitney tests. Results: Both PBM-T alone and PBM-T+PDT yielded significant reductions in OM grade (p < 0.01). PDT+PBM-T resulted in a significantly shorter healing time compared with PBM-T alone (p = 0.0321). Conclusions: Within the parameters of this study, PBM-T+PDT was an effective method to accelerate the OM healing process.

Comparative assessment of two calculation methods for change dynamics in the major fatty acid content of Triticum aestivum L. wheat calli under the action of low-intensity laser radiation

The aim of the present work involves a comparative analysis of the changes in the absolute content of the main fatty acid (FA) component of the total lipid amount in wheat calli (Triticum aestivum L.) under the action of low-intensity laser radiation (LILR), as well as an assessment of the influence of the FA proportion calculation method on the resultant picture of the FA change dynamics. The content of major FAs in callus tissue and its changes when exposed to LILR were determined using gas chromatography-mass spectrometry. A comparative analysis of the calculation results of the absolute (μg/g dry weight) and relative (in %wt. of the sum of the areas of chromatographic peaks) content of the target components (palmitic, stearic, linoleic and linolenic acids) was carried out. When comparing the two calculation methods, no qualitative differences in the change dynamics were observed. At the same time, significant differences were found between the quantitative indicators of the FA content in absolute and relative units. For example, the absolute amount of monounsaturated oleic acid five minutes increased by 23% following the removal of laser radiation, while the relative amount increased by only 14%. For polyunsaturated linoleic and linolenic acids, this difference was even more significant. In general, the trends in changes caused by irradiation in the main fatty acid content compared with the total callus lipids appear to be similar to the stress response of plant tissue to adverse environmental conditions. The scope of two methods for calculating the content of FAs is also discussed.

The technology of laser cataract extraction in diabetic patients

In 1994, academician S.N. Fyodorov directed the development of laser cataract extraction (LCE) technique, which does not require manual or ultrasonic lens fragmentation. To determine the effectiveness and safety of Russian LCE technology in patients with diabetes mellitus using comparative analysis, and to develop practical guidelines. The study analyzed the results of 154 operations in patients with complicated cataract and diabetes mellitus (DM). 80 LCE operations and 74 ultrasonic cataract phacoemulsification (PhEC) surgeries including implantation of intraocular lens were performed. The duration of DM was 12.5±7.1 years in the LCE group and 11.9±7.3 years in the PhEC group. The energy of neodymium Nd:YAG laser endo-dissector with original wavelength of 1.44 μm together with low-intensity He-Ne laser radiation of 0.63 μm were delivered simultaneously to the eye cavity. Corneal endothelial cells loss was significantly lower (by 1.8 times) after LCE, in the early postop period, in 1 year, and 2 years after the surgery; the incidence of intraocular pressure increase and ciliary body edema were lower as well. Moreover, there is no negative influence on the posterior segment of the eye because the radiation of laser endo-dissector during the duty cycle of cataract removal does not extend beyond the lens capsule, and does not affect other tissues of the eye. In comparison to ultrasound cataract surgery, LCE is a more safe and effective method of removing complicated cataracts in diabetic patients with any degree of lens density.

Возможности низкоинтенсивного лазерного облучения крови и аспекты доказательности его эффективности в лечении контузионных очагов и внутричерепных гематом малого объёма

Возможности низкоинтенсивного лазерного облучения крови и аспекты доказательности его эффективности в лечении контузионных очагов и внутричерепных гематом малого объёма

Effect of Low-Frequency Pulsed Magnetic Field and Low-Level Laser Radiation on Oxidoreductase Activity and Growth of Fungi—Active Destructors of Polymer Materials

Effect of low-frequency pulsed magnetic field and of low-intensity laser radiation on mycelial fungi actively degrading various polymer materials was studied. These factors had a different effect on spores of fungi and mycelia. Irradiation could stimulate and suppress fungal growth. The studied physical factors had dose-dependent effects on activity of the extracellular fungal oxidoreductases (catalase and peroxidase); both increased and decreased enzymatic activities were observed.

An Experimental Study of the Specific Features of Laser Radiation Propagation through the Optical System of the Human Eye and the Optic Nerve

The results of studies of the process of low-intensity laser radiation propagation through human optic pathways are presented. It is shown that the optic nerve can be modeled as a fiber optic cable rather than a coaxial electric cable.

The Capabilities of Interference Microscopy in Studying the in vitro State of Erythrocytes Exposed to Low-Intensity Laser Radiation for Stress Correction

The Capabilities of Interference Microscopy in Studying the in vitro State of Erythrocytes Exposed to Low-Intensity Laser Radiation for Stress Correction

Physiotherapy in the Medical Rehabilitation of Children with Malignant Tumors

Analyzed studies on the use of physical factors in the medical rehabilitation of children with malignant tumors were enrolled from the following electronic databases: Scopus, Web of Science, MedLine, World Health Organization, The Cochrane Central Register of Controlled Trials, Cochrane Childhood Cancer Group, ScienceDirect, US National Library of Medicine National Institutes of Health, PubMed Cancer, elibrary, CyberLeninka. To treat complications that occur in children both during and after chemotherapy/radiotherapy for malignant tumors, physical training, massage, acupuncture, acupressure, electroneurostimulation, low-intensity laser radiation, laser irradiation of blood, laser puncture, magnetolaser therapy, local low-frequency low-intensity magnetotherapy were applied in an independent mode. Complex of artificial and natural medical factors in the rehabilitation of children in the period of remission was studied on the bases of various sanatoriums. Its clinical efficacy was practically assured but precise evidence of safety was not obtained yet. Nevertheless basing on this review, we can declare that the approach to pediatric oncology rehabilitation should be multidisciplinary. On the one hand, the therapy without physiotherapy intervention is absolutely unjustified; on the other hand, the application of various physical factors is also reckless. The physical factors included in the rehabilitation complex should be safe with no negative effect on the course of the underlying disease in children. To obtain such convincing evidence, it is extremely important both to analyze the long-term results of conducted studies (analysis should be performed by rehabilitation physicians together with oncologists who supervised pediatric patients) and to conduct well-organized controlled randomized academic studies on large clinical material.

Realization of Macromycete Photoinduced Growth Activity: Influence of Cultivation Ways and the Concentration of Carbon and Nitrogen

Background. Scientific principles of the biosynthetic activity photoregulation of edible and medicinal macromycetes.Objective. The aim of the paper is to determine the influence of macromycete cultivation method, carbon and nitrogen concentration on the realization of their photoinduced growth activity.Methods. Seed mycelium C. militaris, F. velutipes, H. erinaceus, L. edodes, and P. ostreatus irradiated with low-intensity laser light in different wavelength ranges at an energy dose of 230 mJ/сm2, was cultivated superficially on a liquid medium, and also by the deep cultivation method. As carbon source glucose was used, nitrogen – peptone at various concentrations. The biomass accumulation and glucose consumption efficiency were determined.Results. It is proved that the realization degree of the photoinduction depends on the composition of the nutrient medium and the method of macromycete cultivation. It is established that in order to obtain the maximum stimulating effect after low-intensity laser radiation, a deep cultivation of the photoactivated seed mycelium should be carried out. A short-term low-intensity laser radiation results in a change in the trophism of macromycetes and is expressed in an increase in the biomass accumulation rate and in the efficiency of glucose consumption. Reducing the glucose concentration in the medium increases the photoinduced activity of the seed mycelium C. militaris, G. lucidum, L. edodes, H. erinaceus, and P. ostreatus. There was no significant effect of nitrogen concentration on photoinduced stimulation of macromycete growth.Conclusions. The results of the research are the basis for further studies of the influence of various factors on the photoinduction of the biosynthetic activity of edible and medicinal mushrooms to intensify the technological stages of their cultivation.

Effect of Laser Irradiation on Cell Cycle and Mitosis.

Introduction: In this research, low-level helium-neon (He-Ne) laser irradiation effects on monkey kidney cells (Vero cell line) mitosis were studied. Methods: The experiment was carried out on a monkey kidney cell line "Vero (CCL-81)". This is a lineage of cells used in cell cultures and can be used for efficacy and media testing. The monolayer cells were formed on coating glass in a spectral cuvette (20×20×30 mm). The samples divided into two groups. The first groups as irradiated monolayer cells were exposed by a He-Ne laser (PolyaronNPO, L'vov, Ukraine) with λ=632.8 nm, max power density (P) = 10 mW/cm2 , generating linearly polarized and the second groups as the control monolayer cells were located in a cuvette protected by a lightproof screen from the first cuvette and also from the laser exposure. Then, changing functional activity of the monolayer cells, due to the radiation influence on some physical factors were measured. Results: The results showed that low-intensity laser irradiation in the range of visible red could make meaningful changes in the cell division process (the mitosis activity). These changes depend on the power density, exposure time, the presence of a magnetic field, and the duration of time after exposure termination. The stimulatory effects on the cell division within the power density of 1-6 mW/(cm2 ) and exposure time in the range of 1-10 minutes was studied. It is demonstrated that the increase in these parameters (power density and exposure time) leads to destructing the cell division process. Conclusion: The results are useful to identify the molecular mechanisms caused by low-intensity laser effects on the biological activities of the cells. Thus, this study helps to optimize medical laser technology as well as achieving information on the therapeutic effects of low-intensity lasers.

USE OF LOW-INTENSITY LASER RADIATION IN REHABILITATION OF HYPOTROPHIC CALVES

The effect of low-intensity laser radiation on the biochemical, immune and clinicalstatus of hypotrophic calves was studied. The studies were carried out in 2 groups(test and control ones) of 12 animals with symmetric moderate hypotrophy. Thecalves in the test group underwent low-intensity laser irradiation of blood withinthe red spectral range (wave length of 630 nm). The animals of the control group(intact) were not treated. Clinical observations of the calves were carried out during2 months, taking into account the incidence, duration and severity of the course ofthe disease, as well as the calves’ weight gain. Blood sampling for biochemical andimmunological studies was performed on the 1st and the 21st days of the calves’life. On the first day the biochemical status and natural resistance in the animals ofthe both groups did not differ. On the 21st day, the calves of the test group hadhigher levels of glucose, pyruvic acid, vitamin E, Blood Serum ComplementActivity (SCA), Blood Serum Lysozyme Activity (SLA), Leucocyte PhagocyticActivity (LPA), Phagocytic Number (PN), Phagocytic Intensivity (PI), and lowerlevels of lactic acid, middle molecules and ectoglobular hemoglobin in comparisonwith the control group. The treatment of the animals with low-intensity laserradiation positively affected their clinical state and productivity. The calves in thetest group had mild forms of gastrointestinal diseases with a shorter courseduration, and the increase in body weight was significantly higher compared withthe control group. The positive effects of low-intensity laser radiation onbiochemical status, natural resistance and clinical condition of hypotrophic calveswere established, which allows us to recommend it for their rehabilitation.

ОЦЕНКА ВЛИЯНИЯ НИЗКОИНТЕНСИВНОГО ЛАЗЕРНОГО ИЗЛУЧЕНИЯ НА МОРФОЛОГИЮ ЭРИТРОЦИТОВ ПРИ СТРЕССЕ МЕТОДОМ ЛАЗЕРНОЙ ИНТЕРФЕРЕНЦИОННОЙ МИКРОСКОПИИ

ОЦЕНКА ВЛИЯНИЯ НИЗКОИНТЕНСИВНОГО ЛАЗЕРНОГО ИЗЛУЧЕНИЯ НА МОРФОЛОГИЮ ЭРИТРОЦИТОВ ПРИ СТРЕССЕ МЕТОДОМ ЛАЗЕРНОЙ ИНТЕРФЕРЕНЦИОННОЙ МИКРОСКОПИИ

Effect of Laser Therapy on the Osseointegration of Immediately Loaded Dental Implants in Patients under Vitamin C, Omega-3 and Calcium Therapy.

BACKGROUND:The use of laser therapy in the biostimulation of bone repair has been growing steadily.AIM:This study aimed to evaluate the radio-densitometric effect of low-intensity laser therapy on the osseointegration of immediately loaded dental implants in patients under vitamin C, omega-3 and calcium therapy.PATIENTS AND METHODS:A single implant was placed in the mandibular first molar region of twenty patients which were equally divided into two groups. In the non-laser group, the healing phase was left to progress spontaneously without any intervention, while in the laser group it was augmented with low-level laser therapy of wavelength 904 nm in contact mode, continuous wave, 20 mW output power and exposure time 30 sec with a dose 4.7 J/cm2. Patients in both groups were given vitamin C, calcium and omega-3 starting one month preoperatively. Postoperative digital panoramas were taken immediately after surgery, 1.5 months and 6 months postoperatively. Changes in bone density along the bone-implant interface at the mesial, distal and apical sides were assessed using the Digora software.RESULTS:Independent student t-test was used to compare means of variables between the laser and the non-laser group while repeated measures ANOVA was used to compare bone densities at different times for the same group. Significant increased differences were observed at the mesial, distal and apical sides surrounding the implants of both groups per time. However, the rate of increase was significantly higher in the laser group. The mean difference at the mesial side after 6 months was 21.99 ± 5.48 in the laser group and 14.21 ± 4.95 in the non-laser group, while it read 21.74 ± 3.56 in the laser group and 10.78 ± 3.90 in non-laser group at the distal side and was 18.90 ± 5.91 in the laser group and 10.39 ± 3.49 in non-laser group at the apical side. Significance was recorded at P = 0.004, P = 0.0001, and 0.001 at the mesial, distal and apical sides respectively.CONCLUSION:The low-intensity laser irradiation significantly promoted bone healing and speeded up the osseointegration process emphasising the laser’s biostimulatory effect.

Effects of light-emitting diodes irradiation on human vascular endothelial cells.

Endothelial cell proliferation is a hallmark of angiogenesis and plays a key role in the process of tissue repair. Low-intensity (670 nm) laser irradiation influences endothelial cell proliferation in vitro. Light in the near infrared spectrum may have clinical applications in erectile dysfunction. The purpose of this study was to investigate the effects of irradiation with light-emitting diodes (LEDs) at different wavelengths on human vascular endothelial cells in vitro. Human umbilical vein endothelial cells (HUVECs) were irradiated with LEDs at 410, 480, 595, and 630 nm in doses of 1, 2.5, 5, and 10 J/cm2. After 24 h of LED irradiation, effects on cell viability, nitric oxide (NO) secretion, and eNOS expression were assessed by using cell viability assays, Western blot, and real time-polymerase chain reaction, respectively. The cell viability assay demonstrated that irradiation with LEDs at 630 nm significantly increased the proliferation of HUVECs. In addition, irradiation with LEDs at 630 nm was more effective in stimulating NO secretion and eNOS expression from HUVECs than irradiation with LEDs at 410, 480, and 595 nm. Irradiation with LEDs at 630 nm was effective for inducing cell proliferation, NO secretion, and eNOS expression in HUVECs. These results suggest that irradiation with LEDs at 630 nm may be a therapeutic strategy for vasculogenic erectile dysfunction.