Antimicrobial photodynamic therapy with methylene blue and its derivatives in animal studies: Systematic review.

BACKGROUND: Infections are complications in the wound healing process, and their treatment can lead to antibiotic overuse and bacterial resistance. Antimicrobial photodynamic therapy (aPDT) is used to treat infectious diseases caused by fungi, viruses, or bacteria. Methylene blue (MB) and its derivatives are commonly used dyes in antimicrobial photodynamic therapy (aPDT-MB). METHODS: This study is a PRISMA systematic review of animal models used to discuss the usefulness and therapeutic parameters of aPDT-MB or its derivatives for treating infected skin wounds. RESULTS: After an extensive literature review, 13 controlled trials totaling 261 animals were selected to evaluate skin infection by leishmaniasis and cutaneous bacterial and fungal infections. All studies found results favoring the use of aPDT-MB. Great variability in parameters was found for radiant exposure from 12 to 360 J/cm2, MB diluted in saline solution or distilled water, irradiation time from 40 to 3600 s, irradiance most commonly at a maximum of 100 mW/cm2, and wavelength used mainly in the 630-670 nm range. CONCLUSION: MB is a safe and promising agent used as a photosensitizer in aPDT for skin-infected lesions. There is great variability in the parameters found. Comparisons concerning concentration, irradiation time, and light intensity need to be performed.

The role of photobiomodulation when associated with microneedling in female pattern hair loss: A randomized, double blind, parallel group, three arm, clinical study protocol.

The female hair loss pattern was originally described as a synonym for androgenetic alopecia. It has been defined as progressive miniaturizations of the hair follicles, with a great impact on the quality of life of affected patients, causing significant psychosocial limitations. It was recently proven that photobiomodulation is a safe and effective way to treat the different types of hair loss. It was also known that microneedling is a minimally invasive dermatological procedure that is applied to a wide range of dermatological conditions, including androgenic alopecia, telogen effluvium, as well as other facial and bodily conditions. GOAL: The aim of this study is to verify if there is an increase in the capillary density of strands of hair, when combining 660 nm red laser photobiomodulation and microneedling in addressing female pattern hair loss (FPHL). METHODS: There will be 66 patients divided into 3 treatment groups. G1: microneedling and 660 nm red laser photobiomodulation sham; G2: 660 nm red laser photobiomodulation and microneedling sham; G3: microneedling and 660 nm red laser photobiomodulation. The treatment will consist in 36 sessions, 3 times a week for 3 consecutive months, with an insertion of microneedling every 30 days. The patients and the researchers will be blinded. The patients will be evaluated before, during, and after the treatments, by digital photography and the trichoscopy method (dermoscopic imaging of the scalp and hair). EXPECTED RESULTS: It is expected that differences will be found in the growth rates of a strand of hair in mm/d, in the density of a strand of hair in n/cm, in the diameter of a strand of hair, as well as in the anagen/telogen ratio. ETHICS AND DISSEMINATION: This protocol was approved by the Research Ethics Committee of the Nove de Julho University, São Paulo, Brazil, on the date of November 28, 2018 (CAAE: 01381718.0.0000.5511 - Acceptance Number: 3044061). This trial has been registered with the Brazilian Registry of Clinical Trials (REBEC TRIAL RBR-76VCCV). This study is not yet recruiting. Issue date: February 20, 2019.

Controlling methylene blue aggregation: a more efficient alternative to treat Candida albicans infections using photodynamic therapy.

Methylene Blue (MB) has been widely used in antimicrobial Photodynamic Therapy (aPDT), however, the mechanisms of action (Type I or Type II) are defined by its state of aggregation. In this sense, the identification of the relationships between aggregation, the mechanisms of action and the effectiveness against microorganisms, as well as the establishment of the means and the formulations that may favor the most effective mechanisms, are essential. Thus, the objective of this study was to assess the in vitro aPDT efficacies against Candida albicans, by using MB in vehicles which may influence the aggregation and present an oral formulation (OF) containing MB, to be used in clinical aPDT procedures. The efficacy of MB at 20 mg L-1 was tested in a range of vehicles (water, physiological solution - NaCl 0.9%, phosphate saline buffer - PBS, sodium dodecyl sulfate 0.25% - SDS and urea 1 mol L-1) in a C. albicans planktonic culture, when using 4.68 J cm-2 of 640 ± 12 nm LED for the irradiations, as well as 5 minutes of pre-irradiation time, together with measuring the UFC mL-1. Based upon these analyses, an OF containing MB in the most effective vehicle was tested in the biofilms, as a proposal for clinical applications. When comparing some of the vehicles, sodium dodecyl sulfate was the only one that enhanced an MB aPDT efficacy in a planktonic C. albicans culture. This OF was tested in the biofilms and 50 mg L-1 MB was necessary, in order to achieve some reduction in the cell viabilities after the various treatments. The light dosimetries still need further adaptations, in order for this formulation to be used in clinical applications. The present research has indicated that the development of this formulation for the control of MB aggregations may result in more effective clinical protocols.

Low-level laser treatment applied at auriculotherapy points to reduce postoperative pain in third molar surgery: A randomized, controlled, single-blinded study.

OBJECTIVE: Evaluate the effectiveness of LLL (Low level laser therapy) in auriculotherapy points for pain reduction following lower third molar extractions. STUDY DESIGN: Randomized, controlled, single-blinded study. METHODS: Eighty-four bilateral, symmetrical third molar surgeries were performed in 42 healthy patients using a split-mouth design. In the immediate postoperative period, each side was randomly treated in a single-blind method with an LLL at the auriculotherapy points or simulation of its use (contralateral side) over a 21-day interval. This protocol was repeated 24 and 48 hours after surgery. All patients used the same analgesic (paracetamol) but only in case of pain. The primary variable was postoperative pain according to the visual analogue scale, and the secondary variables were mouth opening, edema, local temperature, dysphagia, and the presence of infection (systemic temperature, lymphadenopathy). These variables were evaluated at baseline and at 24 hours, 48 hours and seven days after surgery. Adverse effects were recorded and reported. RESULTS: There was no difference between the groups in relation to any of the evaluated parameters (p>0.05). CONCLUSION: For this experimental model, application of a low-intensity laser at auriculotherapy points did not prevent postoperative pain following lower third molar surgery. TRIAL REGISTRATION: This trial is registered at ClinicalTrials.gov; the registration number is NCT02657174 and the Unique Protocol ID number is 1.100.869. (https://register.clinicaltrials.gov/prs/app/template/EditRecord.vm?epmode=View&listmode=Edit&uid=U0002BEY&ts=11&sid=S0006026&cx=6g4wff).

Effect of photobiomodulation treatment in the sublingual, radial artery region, and along the spinal column in individuals with multiple sclerosis: Protocol for a randomized, controlled, double-blind, clinical trial.

BACKGROUND: Multiple sclerosis (MS) is an autoimmune disease, for which the forms of treatment are medication and rehabilitation. However, in vitro and in vivo studies have demonstrated that photobiomodulation can be an effective treatment modality for inflammatory diseases, including MS. Photobiomodulation has a broad range of benefits, such as the avoidance of cell and tissue death, the stimulation of healing and injury repair, reductions in pain, edema and inflammation, cell proliferation, and even apoptosis. The outcomes of photobiomodulation include the regeneration of cells, the stimulation of the growth of Schwann cells, a reduction in spasticity, functional improvements, a reduction in nitric oxide levels, and the upregulation of the cytokine IL10, demonstrating that this therapeutic modality can offer neuroprotection. METHODS: A randomized, controlled, double-blind, clinical trial is proposed. The patients will be divided into 6 groups. Groups 1 and 2 will receive sham and active photobiomodulation in the sublingual region, respectively. Groups 3 and 4 will receive sham and active photobiomodulation along the spinal cord, respectively. Group 5 will receive placebo treatment with photobiomodulation on the skin in the region of the radial artery with a specific bracelet. Group 6 will be treated with photobiomodulation on the skin in the region of the radial artery. DISCUSSION: Treatment for MS is directed at the immune response and slowing the progression of the disease. This is one of the first clinical trials involving photobiomodulation in the sublingual region and along the spinal cord, which could help establish a promising new form of nonpharmacological treatment for autoimmune diseases. This is one of the first clinical trials with sublingual photobiomodulation and along the spinal cord that could help establish a new form of promising treatment of the disease associated with pharmacological treatment.

Oral hygiene in intensive care unit patients with photodynamic therapy: study protocol for randomised controlled trial.

BACKGROUND: In intensive care units (ICUs), nosocomial infections are prevalent conditions and they have been related to high mortality indexes. Some studies have suggested that inefficient oral hygiene and ventilator-associated pneumonia (VAP) are related. Nowadays, in the Brazilian public health system there is no well-defined protocol for oral hygiene in an ICU. Due to the drawbacks of the use of antibiotics, photodynamic therapy (PDT) has emerged as an interesting technique in order to reduce antimicrobial-resistant pathogens. Methylene blue (MB) is the most common chemical agent for PDT in Brazil. However, new formulations for improved effectiveness are still lacking. The objective of this study is to evaluate the use of an MB mouthwash as an effective oral-hygiene procedure in an ICU and to show that oral hygiene using PDT with MB mouthwash may reduce VAP frequency to rates similar to, or higher than, chlorhexidine. METHODS: Phase 1 will evaluate the most effective cleaning procedure, while phase 2 will correlate oral hygiene to VAP incidence. At the start of phase 1, the ICU patients will be randomly allocated into three different groups (10 patients/group): the efficacy of chlorhexidine, classical MB-PDT, and mouthwash MB-PDT will all be measured for the quantification of viable bacteria, both pre- and post-treatment, by a Reverse Transcription Polymerase Chain Reaction (RT-PCR). In phase 2, the most effective procedure found in phase 1 and a mechanical cleaning with filtered water will be carried out daily, once a day, over 5 days, with a total of 52 ICU patients randomly allocated into the two groups. The clinical records will be evaluated in order to find any pneumonic diagnoses. DISCUSSION: Since a variety of bacterial species are related to VAP, a universal primer for bacteria will be used in order to quantify the total bacteria count in the participants' samples. In order to quantify only the living bacteria before DNA extraction, the samples will be treated with propidium monoazide. This will infiltrate the dead bacteria and will intercalate the DNA bases, avoiding their DNA amplification. This will be the first trial to evaluate MB-PDT in a mouthwash formula that can increase the effectiveness due to the control of MB aggregation. The results of this study will be able to generate an easy and low-cost protocol to be used in an ICU for the Brazilian public health system. TRIAL REGISTRATION: This protocol was approved by the Research Ethics Committee of the Conjunto Hospitalar do Mandaqui (1.317.834, CAAE: 49273515.9.3001.5551) and it was registered in Registro Brasileiro de Ensaios Clínicos (ReBEC number: RBR-94bvrc;). First received: 12 July 2015; 1st version 6 June 2016. Data will be published in a peer-reviewed journal.

Light-emitting diode therapy increases collagen deposition during the repair process of skeletal muscle.

This study analyzed the effects of light-emitting diode (LED) therapy on the morphology of muscle tissue as well as collagen remodeling and matrix metalloproteinase 2 (MMP-2) activity in the skeletal muscle of rats following acute injury. Wistar rats were divided into four groups: (1) control, (2) sham, (3) untreated cryoinjury, and (4) cryoinjury treated with LED. Cryoinjury was induced by two applications of a metal probe cooled in liquid nitrogen directly onto the belly of the tibialis anterior muscle. For treatment, the LED equipment (wavelength 850 nm, output power 30 mW, and total energy 3.2 J) was used daily. The study periods were 1, 3, and 7 days after cryoinjury. Morphological aspects were evaluated through hematoxylin-eosin staining. The amount of collagen fibers was evaluated using Picro Sirius Red staining under polarized light. The gelatinase activity of MMP-2 was evaluated using zymography. The results showed significant reductions in inflammatory infiltrate after 3 days and an increased number of immature muscle fibers after 7 days. Furthermore, treatment induced a reduction in the gelatinolytic activity of MMP-2 after 1, 3, and 7 days in comparison to the untreated injury groups and increased the collagen deposition after 3 and 7 days in the treated groups. LED therapy at 850 nm induced a significant reduction in inflammation, decreased MMP-2 activity, and increased the amount of immature muscle and collagen fibers during the muscle repair process following acute injury.

Collagen birefringence in skin repair in response to red polarized-laser therapy.

We use the optical path difference (OPD) technique to quantify the organization of collagen fibers during skin repair of full-thickness burns following low-intensity polarized laser therapy with two different polarization incidence vectors. Three burns are cryogenerated on the back of rats. Lesion L(parallel) is irradiated using the electric field vector of the polarized laser radiation aligned in parallel with the rat's occipital-caudal direction. Lesion L(perpendicular) is irradiated using the electric field vector of the polarized laser radiation aligned perpendicularly to the aforementioned orientation. Lesion C is untreated. A healthy area labeled H is also evaluated. The tissue samples are collected and processed for polarized light microscopy. The overall finding is that the OPD for collagen fibers depends on the electric field vector of the incident polarized laser radiation. No significant differences in OPDs are observed between L(parallel) and H in the center, sides, and edges of the lesion. Lesions irradiated using the electric field vector of the polarized laser radiation aligned in parallel with the rat's occipital-caudal direction show higher birefringence, indicating that collagen bundles in these lesions are more organized.

Effects of low-intensity polarized visible laser radiation on skin burns: a light microscopy study.

OBJECTIVE: This study was carried out to investigate the influence of low-intensity polarized visible laser radiation on the acceleration of skin wound healing. BACKGROUND DATA: Low-level laser therapy (LLLT) at adequate wavelength, intensity, and dose can accelerate tissue repair. However, there is still unclear information about light characteristics, such as coherence and polarization. Some studies indicate that linearly polarized light can survive through long propagation distance in biological tissue. MATERIALS AND METHODS: Three burns about 6 mm in diameter were created on the back of rats with liquid N(2). Lesion "L(//)" was irradiated by He-Ne laser (lambda = 632.8 nm), D= 1.0 J/cm(2), with linear polarization parallel to the spinal column of the rat. Lesion "L(inverted v)" was irradiated using the same laser and dose, but the light polarization was aligned perpendicularly to the relative orientation. Lesion "C" was not irradiated in order to be considered as control. The animals were sacrificed at day 3-17 after lesion creation. Samples were collected and prepared for histological analysis. RESULTS: Histological analysis showed that the healing of irradiated wounds was faster than that of non-irradiated wounds. Moreover, it was observed that skin wound repair is dependent on polarization orientation with respect to a referential axis as the animal's spinal column. Consequently, "L(//)" was completely healed after 17 days, whereas "L (perpendicular) " showed a moderate degree of healing after the same period. CONCLUSIONS: These results indicate that the relative direction of the laser polarization plays an important role in the wound healing process when highly coherent He-Ne laser is used.