Cardiopulmonary and hematological effects of infrared LED photobiomodulation in the treatment of SARS-COV2.

BACKGROUND: COVID-19 disease is caused by SARS-CoV-2 which can trigger acute respiratory syndrome, which presents with dense alveolar and interstitial infiltrates and pulmonary edema, causing severe hypoxemia and significant alteration to pulmonary mechanics with reduced pulmonary compliance. The photobiomodulation technique alters cellular and molecular metabolism, showing promising results regarding the reduction of acute pulmonary inflammation. OBJECTIVE: To compare the photomodulation technique using near-infrared LED to conventional respiratory physiotherapy treatment in patients with COVID-19 in reversing acute conditions, reducing hospitalization time, and decreasing the need for oxygen therapy. METHODOLOGY: The cohort was comprised of 30 patients undergoing COVID-19 treatment who were divided and allocated into two equal groups randomly: the LED group (LED), treated with infrared LED at 940 nm and conventional therapy, and the control group (CON), who received conventional treatment (antibiotic therapy for preventing superimposed bacterial infections, and physiotherapy) with LED irradiation off. Phototherapy used a vest with an array of 300 LEDs (940 nm) mounted on a 36 cm × 58 cm area and positioned in the patient's anterior thoracic and abdominal regions. The total power was 6 W, with 15 min irradiation time. Cardiopulmonary functions and blood count were monitored before and after treatment. The patients were treated daily for 7 days. Statistical analysis was conducted using a two-tailed unpaired Student's t-test at a significance level of α = 0.05. RESULTS: Post-treatment, the LED group showed a reduction in hospital discharge time and a statistically significant improvement for the following cardiopulmonary functions: Partial Oxygen Saturation, Tidal Volume, Maximum Inspiratory, and Expiratory Pressures, Respiratory Frequency, Heart Rate, and Systolic Blood Pressure (p < 0.05). Regarding blood count, it was observed that post-treatment, the LED group presented with significant differences in the count of leukocytes, neutrophils, and lymphocytes. CONCLUSION: Photobiomodulation therapy can be used as a complement to conventional treatment of COVID-19, promoting the improvement of cardiopulmonary functions, and minimization of respiratory symptoms.

Analysis of pain relief and functional recovery in patients with rotator cuff tendinopathy through therapeutic ultrasound and photobiomodulation therapy: a comparative study.

This study aimed to compare shoulder tendinopathy treatment with therapeutic ultrasound combined with LED photobiomodulation therapy using LED-infrared (850 nm) or LED-red (640 nm). The study assessed 75 patients, aged 45 to 70 years, distributed into five experimental groups (15 patients each): therapeutic ultrasound (US), infrared light irradiation (IR), visible red light irradiation (VR), infrared light and ultrasound combined (IR-US), and red light in conjunction with ultrasound (VR-US). The ultrasound parameters are 1 MHz, 0.5 W/cm2 (SATA), and 100 Hz repetition rate, applied for 4 min each session. LED irradiation protocols were as follows: 3 points, 7.5 J per point, IR-LED 750 mW, 10 s, VR-LED 250 mW, 30 s. LED irradiation is followed by ultrasound in the combined therapies. The efficiency of the five therapies was evaluated assessing 12 parameters: quality of life (Health Assessment Questionnaire, HAQ), pain intensity (Visual Analog Scale, VAS), articular amplitude of shoulder movement (flexion, extension, abduction, adduction, medial rotation, lateral rotation), muscle strength (abduction, lateral rotation), and electromyography (lateral rotation, abduction). Treatments comprised 12 sessions for 4 weeks. Intra-group analysis showed that the five therapies significantly improved the recovery of all parameters after treatment. Regarding the comparison of irradiated therapies and ultrasound, statistical analysis showed that IR-US was a better treatment than US for all 12 parameters. IR treatment exceeded US on 9 items, whereas that VR and VR-US therapies exceeded US in 7 and 10 parameters, respectively (p < 0.05). Because of that, IR-US shows to be the best treatment for rotator cuff tendinopathy. In conclusion, improvements in quality of life, pain intensity relief, shoulder amplitude motion, and muscle strength force obtained with ultrasound therapy are enhanced by adding infrared LED irradiation to ultrasound for patients suffering from rotator cuff tendinopathy. This study was registered with the Brazilian Registry of Clinical Trials (ReBEC) under Universal Trial Number (UTN) U1111-1219-3594 (2018/22/08).

Systemic Effects of Photobiomodulation on Blood Components in the Treatment of Community-Acquired Pneumonia.

Background: The analysis of the complete blood count (CBC) of patients with community-acquired pneumonia (CAP) is an essential practice both for diagnosing the disease and for evaluating the patient's clinical evolution. It is proposed in the present study to analyze the hematological alterations resulting from photobiostimulation using near-infrared light-emitting diodes (LEDs) in patients with CAP. Methods: This was a clinical, prospective, blinded, and descriptive longitudinal study that involved 21 patients undergoing CAP treatment who were divided into two groups: LED, 11 patients who were treated with infrared LED and conventional treatment; and CON (control), 10 patients who received only conventional treatment (antibiotic therapy and physiotherapy). Physiotherapy was applied before LED irradiation in the LED group. The patients' CBCs were obtained before and after treatment, and erythrocyte counts, hemoglobin and hematocrit concentrations, and leukocyte and platelet counts were assessed. The phototherapy was performed with a vest with an array of 300 LEDs (940 nm) mounted on an area of 36 × 58 cm and positioned in the patient's anterior thoracic and abdominal regions. The total power was 6 W, with 15 min of irradiation time. The patients were treated daily for seven consecutive days. Statistical analyses of the intra- and intergroups of CBC data were done using Student's t-test and one-way ANOVA (analysis of variance), respectively, both at the significance level of α = 0.05. Results: There was a statistically significant recovery difference after treatment in the LED group compared with the CON group for erythrocytes, hemoglobin, leukocytes, segmented and band neutrophils, lymphocytes, and monocytes (p < 0.05). The greatest differences between the LED and CON groups were lymphocyte count reduction (60% vs. 16%), erythrocyte increase (86% vs. 35%), and leukocyte reduction (28% vs. 15%). Conclusions: The hematologic components of CAP patients recovered their normal values faster with conventional treatment associated with infrared LED therapy, thus indicating greater treatment efficiency when compared with the conventional therapy. This study was registered with the Brazilian Registry of Clinical Trials (ReBeC) under Universal Trial Number (UTN) U1111-1229-1296 (2019/06/05).

Photobiomodulation: Shining Light on COVID-19.

Objective: To evaluate the hypothesis that light could reduce the lethality of COVID-19. Methods: Most models for projections of the spread and lethality of COVID-19 take into account the ambient temperature, neglecting light. Recent advances in understanding the mechanism of action of COVID-19 have shown that it causes a systemic infection that significantly affects the hematopoietic system and hemostasis, factors extremely dependent of light, mainly in the region of visible and infrared radiation. Results: In the COVID-19 patients hemoglobin is decreasing and protoporphyrin is increasing, generating an extremely harmful accumulation of iron ions in the bloodstream, which are able to induce an intense inflammatory process in the body with a consequent increase in C-reactive protein and albumin. Observing the unsaturation characteristics of the cyclic porphyrin ring allows it to absorb and emit radiation mainly in the visible region. This characteristic can represent an important differential to change this process in the event of an imbalance in this system, through the photobiomodulation to increase the production of adenosine triphosphate (ATP) using red and near-infrared radiation (R-NIR) and vitamin D using ultraviolet B (UVB) radiation. These two compounds have the primary role of activating the defense mechanisms of the immune system, enabling greater resistance of the individual against the attack by the virus. According to the theory of electron excitation in photosensitive molecules, similar to hemoglobin heme, after the photon absorption there would be an increase in the stability of the iron ion bond with the center of the pyrrole ring, preventing the losses of heme function oxygen transport (HbO2). The light is also absorbed by cytochrome c oxidase in the R-NIR region, with a consequent increase in electron transport, regulating enzyme activity and resulting in a significant increase of oxygen rate consumption by mitochondria, increasing ATP production. Conclusions: The most favorable range of optical radiation to operate in this system is between R-NIR region, in which cytochrome c oxidase and porphyrin present absorption peaks centered at 640 nm and HbO2 with absorption peak centered at 900 nm. Based on the mechanisms described earlier, our hypothesis is that light could reduce the lethality of COVID-19.

LED phototherapy in full-thickness burns induced by CO2 laser in rats skin.

Many studies have been conducted on the treatment of burns because they are important in morbidity and mortality. These studies are mainly focused on improving care and quality of life of patients. The aim of this study was evaluate the LED phototherapy effects in rats skin full-thickness burns induced by CO2 laser. The animals were divided in NT group that did not received any treatment and LED group that received LED irradiation at 685 nm, 220 mW, and 4.5 J/cm2 during 40 s by burned area. Biopsies were obtained after 7, 14, and 21 days of treatment and submitted to histological and immunohistochemical analysis. The LED phototherapy shows anti-inflammatory effects, improves angiogenesis, and stimulates the migration and proliferation of fibroblasts. The T CD8+ lymphocytes were more common in burned areas compared to T CD4+ lymphocytes since statistically significant differences were observed in the LED group compared to the NT group after 7 days of treatment. These results showed that LED phototherapy performs positive influence in full-thickness burns repair from the healing process modulated by cellular immune response. The obtained results allowed inferring that burns exhibit a characteristic cell immune response and this cannot be extrapolated to other wounds such as incision and wounds induced by punch, among others.

Use of photodynamic therapy in the treatment of bovine subclinical mastitis.

BACKGROUND: Bovine mastitis is a disease that causes a severe drawback in dairy production. Conventional treatments with antibiotic could leave antibiotic residues in the milk. The aim of this study was to evaluate the effect of photodynamic therapy in the treatment of bovine subclinical mastitis to develop an in vivo therapeutic protocol that could be used in routine farm practice, favoring the early return to production. METHODS: Forty cows with subclinical mastitis (n = 40) were divided into 4 groups (control, photodynamic therapy - PDT, light irradiation - LED, and photosensitizer - PS). Control group received no treatment, PDT group received application of 1.0 mL of 2.5% toluidine blue photosensitizer followed by LED irradiation at λ = 635 nm, the LED group was treated with LED irradiation alone, and the PS group received only 2.5% toluidine blue dye. LED irradiation was applied to the mammary gland by means of an acrylic light guide coupled to the LED equipment. The PDT and LED groups were irradiated with 200 J/cm2 at three different positions inside the mammary gland. Milk samples were collected at 0 h, 12 h, 24 h after treatment for microbial identification and total bacterial count. RESULTS: The treatment of the PDT group showed significant difference p < 0.05, characterizing the efficiency of this technique with the reduction of the microorganisms Streptococcus dysgalactiae and coagulase-negative Staphylococcus. CONCLUSION: Photodynamic therapy was effective when applied in vivo for subclinical bovine mastitis. There was no need to separate the animal from production.

Low intensity laser and LED therapies associated with lateral decubitus position and flexion exercises of the lower limbs in patients with lumbar disk herniation: clinical randomized trial.

UNLABELLED: The objective of this study is to evaluate the effectiveness of laser and LED therapies, associated with lateral decubitus position and flexion exercises of the lower limbs in patients with lumbar disk herniation (LDH). It is a randomized blinded clinical trial. Fifty-four subjects with LDH L4-L5 and L5-S1 were selected and randomly allocated into groups: laser 904 nm, placebo, and LED 945 nm. The numbers of subjects for each group that completed the treatment were 18, 13, and 18, respectively. Twelve points over the lumbar spine region (L2 to S1) and eight points on the injured thigh in the path of the lumbar roots L5 and S1 were irradiated. Irradiation parameters for each point were as follows: laser wavelength 904 ± 10 nm, average power 0.038 ± 20 % W, irradiated area 0.16 cm(2), energy per point 4 J, and treatment time per point 104 s; LED wavelength 945 ± 15 nm, power 0.1 W, irradiated area 1.0cm(2), energy per point 4 J, and treatment time per point 40 s. Lateral decubitus opposite to the side of the radicular was the standard position for all patients. After phototherapy and laser placebo sessions, the subjects performed sequences of flexion exercises of the lower limbs (ten per session) for 15 daily sessions. VARIABLES STUDIED: pain intensity assessed by visual analog scale (VAS), degree of flexion of the affected hip measured by the universal goniometer and functional capacity assessed by the Oswestry Disability Index. The three groups had statistically significant improvement in lumbar and radicular pain, in hip mobility, and in the functional disability index (p ≤ 0.001). There was a statistically significant difference (p = 0.024) in radicular pain between the groups, gait claudication and Oswestry Disability Index. We can conclude that in the treatment of L4-L5 and L5-S1 LDH with radiculopathy, LED, associated with lateral decubitus position and flexion exercises of the lower limbs, showed better therapeutic performance for radicular pain, gait claudication, and functional disability.

Synergic effect of photodynamic therapy with methylene blue and surfactants in the inhibition of Candida albicans.

Photodynamic therapy (PDT) has been originally developed for the treatment of cancer, but it has been successfully employed in the treatment of infectious diseases, including fungal infections. Surfactants are amphiphilic compounds that also have antifungal properties. The present work demonstrates the synergic effect of PDT with methylene blue (MB) and LED combined with four different surfactants in the killing of Candida albicans. Subinhibitory concentrations of CTAC, HPS, SDS and Triton X-100 were tested with MB PDT. The combined therapies proved to be more efficient than PDT or surfactants separately. The best results were obtained with CTAC and HPS and PDT with MB at the concentration of 32 µg/mL. In conclusion, the combination of surfactants and PDT is an alternative antifungal treatment that can achieve more effective performance with minimal discomfort to the patient.

Effect of incoherent LED radiation on third-degree burning wounds in rats.

The main physiological characteristics in a burn process are the increase of the capillary permeability and the occurrence of edema and exudation. Light-emitting diode (LED) has been proposed as treatment of burning. This study investigated the effects of LED on the repair process of rat skin submitted to a third-degree burning. The lesions were produced on the dorsal surface of male Wistar rats. Animals were divided into 4 groups (n = 6) as follows: L1 and L2 groups as LED-treated burned rats, and received LED therapy along 7 and 15 days with 48 hours intervals, respectively; C1 and C2 groups as control, non-treated burned rats. A red LED (640 nm, 30 mW) operating with a fluence of 4 J/cm(2) was used. The wound area was measured daily after irradiation. Animals were euthanized at the 8th and 16th days after burning, and the wound fragment was submitted to histology. The inflammatory cells as well as the damaged area at the 8th day after burns were significantly lower for the LED-treated group when compared to control. Furthermore, the LED phototherapy effect on cellular migration was even more pronounced at the 16th day. Our results indicated that the treatment with a LED system was clearly effective in reducing the number of inflammatory cells and improving the healing process in an experimental model of third-degree burnings.

Anti-inflammatory effect of low-level laser and light-emitting diode in zymosan-induced arthritis.

OBJECTIVE: The aim of this work was to investigate the effect of low-level laser therapy (LLLT) and light-emitting diode (LED) on formation of edema, increase in vascular permeability, and articular joint hyperalgesia in zymosan-induced arthritis. BACKGROUND DATA: It has been suggested that low-level laser and LED irradiation can modulate inflammatory processes. MATERIAL AND METHODS: Arthritis was induced in male Wistar rats (250-280 g) by intra-articular injection of zymosan (1 mg in 50 microL of a sterile saline solution) into one rear knee joint. Animals were irradiated immediately, 1 h, and 2 h after zymosan administration with a semiconductor laser (685 nm and 830 nm) and an LED at 628 nm, with the same dose (2.5 J/cm(2)) for laser and LED. In the positive control group, animals were injected with the anti-inflammatory drug dexamethasone 1 h prior to the zymosan administration. Edema was measured by the wet/dry weight difference of the articular tissue, the increase in vascular permeability was assessed by the extravasation of Evans blue dye, and joint hyperalgesia was measured using the rat knee-joint articular incapacitation test. RESULTS: Irradiation with 685 nm and 830 nm laser wavelengths significantly inhibited edema formation, vascular permeability, and hyperalgesia. Laser irradiation, averaged over the two wavelengths, reduced the vascular permeability by 24%, edema formation by 23%, and articular incapacitation by 59%. Treatment with LED (628 nm), with the same fluence as the laser, had no effect in zymosan-induced arthritis. CONCLUSION: LLLT reduces inflammatory signs more effectively than LED irradiation with similar irradiation times (100 sec), average outputs (20 mW), and energy doses (2 J) in an animal model of zymosan-induced arthritis. The anti-inflammatory effects of LLLT appear to be a class effect, which is not wavelength specific in the red and infrared parts of the optical spectrum.

Comparative analysis of coherent light action (laser) versus non-coherent light (light-emitting diode) for tissue repair in diabetic rats.

The already known benefits produced by the interaction of coherent light (laser) with biologic tissues determine its use as an adjuvant in the treatment of several complications associated with diabetes. Non-coherent light, such as that emitted by light emitting diodes (LEDs), becomes a promising alternative, because of its low cost and easy handling in these applications. Thirty-six rats were given surgical dorsum lesions. The lesions for the control group did not receive any supporting therapy. The other groups were irradiated only once, 30 min after the establishment of the lesion, with LED (640 nm with 40 nm full bandwidth at half maximum) or laser (660 nm). The histomorphological and histomorphometrical parameters were quantified. The coherent and non-coherent lights produced similar effects during a period of 168 h after the lesions had been made. For the group composed of diabetic animals, 72 h after creation of the lesion, it was observed that the therapy with LEDs had been more efficient than that with the laser in the reduction of the wounds' diameters.