Methylene Blue Photodynamic Therapy Research Articles

Efficacy of 5% methylene blue photodynamic therapy in the treatment of potentially malignant oral disorders: a randomized, double-blind, controlled trial

Efficacy of 5% methylene blue photodynamic therapy in the treatment of potentially malignant oral disorders: a randomized, double-blind, controlled trial

Methylene blue photodynamic therapy of deep tissue abscesses: Phase 1 clinical trial and optical spectroscopy results

SignificanceDeep tissue abscesses represent a significant source of morbidity and hospital stay, with standard of care drainage failing in many cases. We investigated photodynamic therapy (PDT) as an adjunct to standard of care, to reduce or eliminate bacterial burden. ApproachA Phase 1 clinical trial was performed to evaluate safety and feasibility of methylene blue (MB) PDT at the time of abscess drainage. Immediately following drainage, MB-PDT was performed. Diffuse reflectance spectroscopy was performed to evaluate abscess wall optical properties. ResultsNo study-related adverse events were noted, and no side effects were observed. PDT was well tolerated by all subjects, and infused MB was recovered in all cases. Optical property measurements showed variability in hemoglobin concentration and oxygenation, as well as MB uptake, between subjects. ConclusionsMB-PDT at the time of percutaneous abscess drainage was safe and feasible, and optical property measurements showed wide variance between subjects.

Treatment planning for photodynamic therapy of abscess cavities using patient-specific optical properties measured prior to illumination

Photodynamic therapy (PDT) is an effective antimicrobial therapy that we used to treat human abscess cavities in a Phase 1 clinical trial. This trial included pre-PDT measurements of abscess optical properties, which affect light dose (light fluence) at the abscess wall and PDT response. This study simulated PDT treatment planning for 13 subjects that received optical spectroscopy prior to clinical PDT, to determine the impact of measured optical properties on ability to achieve fluence rate targets in 95% of the abscess wall. Retrospective treatment plans were evaluated for 3 conditions: (1) clinically delivered laser power and assumed, homogeneous optical properties, (2) clinically delivered laser power and measured, homogeneous optical properties, and (3) with patient-specific treatment planning using measured, homogeneous optical properties. Treatment plans modified delivered laser power, intra-cavity Intralipid (scatterer) concentration, and laser fiber type. Using flat-cleaved laser fibers, the proportion of subjects achieving 95% abscess wall coverage decreased significantly relative to assumed optical properties when using measured values for 4 mW cm−2 (92% versus 38%, p = 0.01) and 20 mW cm−2 (62% versus 15%, p = 0.04) thresholds. When measured optical properties were incorporated into treatment planning, the 4 mW cm−2 target was achieved for all cases. After treatment planning, optimal Intralipid concentration across subjects was 0.14 ± 0.09%, whereas 1% was used clinically. Required laser power to achieve the 4 mW cm−2 target was significantly correlated with measured abscess wall absorption (ρ = 0.7, p = 0.008), but not abscess surface area (ρ = 0.2, p = 0.53). When using spherical diffuser fibers for illumination, both optimal Intralipid concentration (p = 0.0005) and required laser power (p = 0.0002) decreased compared to flat cleaved fibers. At 0% Intralipid concentration, the 4 mW cm−2 target could only be achieved for 69% of subjects for flat-cleaved fibers, compared to 100% for spherical diffusers. Based on large inter-subject variations in optical properties, individualized treatment planning is essential for abscess photodynamic therapy. (Clinical Trial Registration: The parent clinical trial from which these data were acquired is registered on ClinicalTrials.gov as ‘Safety and Feasibility Study of Methylene Blue Photodynamic Therapy to Sterilize Deep Tissue Abscess Cavities,’ with ClinicalTrials.gov identifier NCT02240498).

Evaluation of Daylight Methylene Blue Photodynamic Therapy in Multiple Recurrent Molluscum Contagiosum

Abstract Background Molluscum contagiosum is a common viral infection caused by DNA Poxvirus. Daylight-photodynamic therapy (DL-PDT) is defined as a photochemical reaction used to selectively destroy tissue. Objectives To evaluate the efficacy and safety of daylight methylene blue photodynamic therapy in treatment of multiple recurrent molluscum contagiosum. Subject and methods This is a single blinded controlled prospective interventional clinical study including 20 patients with molluscum contagiosum diagnosed clinically and by dermoscopy. Patients subjected to daylight methylene blue-mediated photodynamic therapy. Topical MB liposomal loaded 10% cream was applied over the lesions area with occlusion and left for 15 minutes. Two leisons were left as control in each studied patient. Patients were instructed to stay outdoors exposing their lesions and the adjacent area to daylight continuously for at least 90 minutes (if it was a sunny day) or 120 minutes (if it was an overcast or partially sunny day) between 11:00 am to 02:00 pm. Treatment sessions were done weekly for 10 weeks or till complete clearance. Follow up of the patients for 6 months after end of study to detect recurrence or appearance of new lesions. Results Daylight MB Mediated PDT response in a total of 20 (100%) studied patients showed Excellent response to treatment shown as complete clearance in 65%( no.=13) of patients, very good response to treatment in 15.0%( no.=3), good response to treatment in 10.0%( no.=2) and poor response to treatment in 10.0%( no.=2). The total number of lesions was 313. Response of the lesions in studied patents to MB-PDT was monitored by dermoscopic follow up of lesions. Lesions showed complete response in 66.5% (no. = 208) of lesions, partial response in 25.2% (no. = 79) of lesions and no response in 8.3% (no. = 26) of lesions. No serious side effects and also MB-DL/PDT is a painless treatment. No relapse was detected at the site of cleared MC or at a near site during the follow-up period of 6 months following the procedure. Conclusion Daylight-PDT using MB is effective in clearing MC lesions, also is safe, easy to carry out, economic, acceptable cosmetic results with no recurrence, convenient especially for children as it is a painless treatment.

Preliminary measurements of optical properties in human abscess cavities prior to methylene blue photodynamic therapy.

As part of our ongoing Phase 1 clinical trial to establish the safety and feasibility of methylene blue photodynamic therapy (MB-PDT) for human deep tissue abscess cavities, we have shown that determination of abscess wall optical properties is vital for the design of personalized treatment plans aiming to optimize light dose. To that end, we have developed and validated an optical spectroscopy system for the assessment of optical properties at the cavity wall, including a compact fiber-optic probe that can be inserted through the catheter used for the standard of care abscess drainage. Here we report preliminary findings from the first three human subjects to receive these optical spectroscopy measurements. We observed wide variability in concentrations of oxy- and deoxy-hemoglobin prior to MB administration, ranging from 7.3-213 μM and 0.1-47.2 μM, respectively. Reduced scattering coefficients also showed inter-patient variability, but recovered values were more similar between subjects (5.5-10.9 cm-1 at 665 nm). Further, methylene blue uptake was found to vary between subjects, and was associated with a reduction in oxygen saturation. These measured optical properties, along with pre-procedure computed tomography (CT) images, will be used with our previously developed Monte Carlo simulation framework to generate personalized treatment plans for individual patients, which could significantly improve the efficacy of MB-PDT while ensuring safety.

Effective Biofilm Eradication on Orthopedic Implants with Methylene Blue Based Antimicrobial Photodynamic Therapy In Vitro.

Periprosthetic joint infections (PJI) are difficult to treat due to biofilm formation on implant surfaces, often requiring removal or exchange of prostheses along with long-lasting antibiotic treatment. This in vitro study investigated the effect of methylene blue photodynamic therapy (MB-PDT) on PJI-causing biofilms on different implant materials. MB-PDT (664 nm LED, 15 J/cm2) was tested on different Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli and Cutibacterium acnes strains in both planktonic form and grown in early and mature biofilms on prosthetic materials (polyethylene, titanium alloys, cobalt-chrome-based alloys, and bone cement). The minimum bactericidal concentration with 100% killing (MBC100%) was determined. Chemical and topographical alterations were investigated on the prosthesis surfaces after MB-PDT. Results showed a MBC100% of 0.5-5 μg/mL for planktonic bacteria and 50-100 μg/mL for bacteria in biofilms-independent of the tested strain, the orthopedic material, or the maturity of the biofilm. Material testing showed no relevant surface modification. MB-PDT effectively eradicated common PJI pathogens on arthroplasty materials without damage to the materials, suggesting that MB-PDT could be used as a novel treatment method, replacing current, more invasive approaches and potentially shortening the antibiotic treatment in PJI. This would improve quality of life and reduce morbidity, mortality, and high health-care costs.

Urea versus fractional Er:YAG laser pretreatment of methylene blue photodynamic therapy in the treatment of moderate toenail onychomycosis: short- and medium-term effects

Keratolytic properties of urea 40% have long time used for the treatment of onychomycosis. Fractional ablative lasers enhance the delivery of topically applied photosensitizers improving photodynamic therapy (PDT) efficacy. The aim of this study was to compare the short- and medium-term efficacy of a pretreatment with urea 40% and fractional Er:YAG (Fr Er:YAG) laser radiation before PDT mediated by methylene blue (MB) for moderate toenail onychomycosis. Twenty-first-toe toenails were randomized to receive either urea 40% (Group I) or Fr Er:YAG laser (Group II) pretreatment and 9 sessions of MB/PDT over the course of 16 weeks. At baseline, 28- and 40-week follow-ups, clinical efficacy was assessed by digital photographs [allowing determination of the onychomycosis severity index (OSI)], whereas mycological efficacy was assessed by histological examination and fungal culture. Details of the side effects and patients’ satisfaction were also recorded. In both groups, a significant decrease in OSI values was observed at the 28-week follow-up and a slight rebound at the 40-week follow-up. The percentage of nail involvement decreased significantly in both groups at the 28-week follow-up, to continue declining gently in Group I at 40 weeks, in contrast to the rebound observed during this period in Group II. The mycological cure rate was 20% and 30% at 28-week follow-up and 70% and 40% at 40-week follow-up, in Group I and II, respectively. Patients reported being fairly satisfied, and no side effects were detected in any groups. Although both pretreatments favor the action of PDT for the treatment of onychomycosis, the use of urea at 40% is more effective in the medium term.

Fractional CO2 laser - assisted methylene blue photodynamic therapy is a potential alternative therapy for onychomycosis in the era of antifungal resistance

BackgroundTreatment of onychomycosis is challenging by virtue of the impact of nail disfigurement, the location of the fungi within the nail and reported antifungal resistance worldwide. Light-based technologies are promising primary or adjunctive therapeutic modalities. We aimed to compare the efficacy of photodynamic therapy and fractional CO2 laser monotherapy either alone or in combination for onychomycosis. Patients and methodsThis prospective randomized comparative study was conducted on 51 onychomycosis patients divided into three groups. In group A, patients were treated using 6 photodynamic therapy sessions using methylene blue and IPL (560 to 700 nm, fluence 12 J/cm2). Group B patients were treated using 6 bimonthly fractional CO2 laser sessions (10,600 nm, 1.600 mj energy and 0.6 mm density) and group C patients were treated using 6 combined fractional CO2 laser and photodynamic therapy sessions. Patients were evaluated mycologically, dermoscopically and clinically by calculation of proximal nail diameter percentage at baseline, monthly, at the end of treatment and after a 6‐month follow‐up period post-treatment. ResultsCandida was the most commonly isolated organismin in 64.7%, 70.6% and 70.6% of the pateints in groups A, B and C, respectively. The dermoscopic findings in the total dystrophic onychomycosis was subungual hyperkeratosis in 6 patients (100%), longitudinal streaks and striae in 1 patient (16.7%). In dorsolateral subungual onychomycosis, jagged proximal edge in 31 patients (70.5%), and pigmentation in 30 patients (68.2%) were noted. In proximal subungual onychomycosis irregular matt patches were seen in 1 patient (100%). Proximal nail diameter percentage showed statistically significant improvement after treatment and 6 months follow up in the 3 studied groups. Mean increase of proximal nail diameter after treatment was highest in group C (52.94 ± 20.24), followed by group B (43.82 ± 21.03) and least in group A (35.29 ± 17.0). This difference was statistically significant (p = 0.044). Reported side effects were mild-moderate pain, discoloration and paronychia. ConclusionWe conclude that fractional CO2 laser and photodynamic monotherapy, and their combination achieve high success rates, good patient satisfaction and safety profile. Fractional CO2-assisted photodynamic therapy is associated with the highest improvement over either fractional CO2 or photodynamic therapy alone.

Phototherapeutic Induction of Immunogenic Cell Death and CD8+ T Cell-Granzyme B Mediated Cytolysis in Human Lung Cancer Cells and Organoids.

Simple SummaryImmunogenic cancer cell death and photodynamic therapy play an important emerging role in cancer treatment. Understanding mechanisms involved in tumor killing via immune cells in response to photodynamic therapy is important for developing new anticancer approaches. In this study, we report that methylene blue photodynamic therapy decreases the proliferation of lung cancer cells and patient derived non-small cell lung cancer organoids via immunogenic cells death and granzyme B mediated cytolysis.Augmenting T cell mediated tumor killing via immunogenic cancer cell death (ICD) is the cornerstone of emerging immunotherapeutic approaches. We investigated the potential of methylene blue photodynamic therapy (MB-PDT) to induce ICD in human lung cancer. Non-Small Cell Lung Cancer (NSCLC) cell lines and primary human lung cancer organoids were evaluated in co-culture killing assays with MB-PDT and light emitting diodes (LEDs). ICD was characterised using immunoblotting, immunofluorescence, flow cytometry and confocal microscopy. Phototherapy with MB treatment and low energy LEDs decreased the proliferation of NSCLC cell lines inducing early necrosis associated with reduced expression of the anti-apoptotic protein, Bcl2 and increased expression of ICD markers, calreticulin (CRT), intercellular cell-adhesion molecule-1 (ICAM-1) and major histocompatibility complex I (MHC-I) in NSCLC cells. MB-PDT also potentiated CD8+ T cell-mediated cytolysis of lung cancer via granzyme B in lung cancer cells and primary human lung cancer organoids.

Effects of methylene blue photodynamic therapy on oral carcinoma and leukoplakia cells.

ObjectiveMethylene blue (MB) is a readily available and affordable substrate that can be used as a photosensitizer for photodynamic therapy (PDT). The objective of this study was to determine if PDT with MB can downregulate matrix metalloproteinases (MMPs) related to oral carcinoma.MethodsCell cultures of oral squamous cell carcinoma (CA‐9‐22), oral leukoplakia (MSK‐Leuk1), and immortalized keratinocytes (Rhek‐1A) were photosensitized with MB and treated with PDT. MMP‐9 gene expression was interrogated via qRT‐PCR. The 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyl‐2H‐tetrazolium bromide (MTT) assay was used to confirm the efficacy of MB PDT.ResultsMMP‐9 gene expression was found to be significantly decreased in oral carcinoma, leukoplakia, and immortalized keratinocytes with use of MB PDT.ConclusionThis work demonstrates that MB‐mediated PDT can downregulate MMPs which are critical to the invasion and metastasis of oral cancer. These results suggest that MB PDT could be a clinically significant and cost‐effective treatment for oral leukoplakia and carcinoma.Level of EvidenceNA

Push out bond strength of glass fiber post to radicular dentin irrigated with Nisin and MTAD compared to methylene blue photodynamic therapy

AimPresent lab-based study intended to appraise the effect of nisin, Mixture of Tetracycline, Acid and Detergent (MTAD), and photodynamic therapy (PDT) when used as a canal disinfectant on push-out bond strength (PBS) of fiber post to radicular dentin Materials and methodsForty uni-radicular premolar teeth were extracted and disinfected in 0.5 % thymol solution. All specimens were decoronated to achieve standardize root length of 14 mm. Cleaning and shaping of the canal were done using protaper NiTi system. The canal space was dried and obturated. Post space was prepared using peso reamers up to 10 mm length and samples were randomly divided into 4 groups (n = 10). Group 1 irrigated with 10 % Nisin with MTAD, group 2: 1.3 % NaOCl and MTAD, Group 3 irrigated with 2.5 % NaOCl and 17 % EDTA and post space of samples in group 4 with PDT with MTAD. Fiber-reinforced composite post (FRCP) was fitted in canal space using self-etch resin cement. Each sample was cut into 1 mm from coronal, middle, and apical and subjected to PBS via a universal testing machine. For comparison of means, Analysis of variance (ANOVA) and Tukey multiple comparison test was used maintaining the level of significance at p < 0.05. ResultSamples in group 3 post space irrigated with 2.5 % NaOCl and 17 % EDTA demonstrated the highest PBS at all root levels (cervical: 8.83 ± 0.14 MPa, middle: 7.63 ± 0.82 MPa and apical: 5.82 ± 0.32 MPa) in comparison to other tested groups. Whereas, group 1 in which Nisin 10 % with MTAD was used as a canal disinfectant displayed the lowest PBS at all levels (cervical: 6.91 ± 0.54 MPa, middle: 6.15 ± 0.31 MPa, and apical: 3.62 ± 0.68 MPa). ConclusionPost space irrigated with 1.3 % NaOCl and MTAD shows PBS similar to control group 2.5 % NaOCl and 17 % EDTA. Both types of irrigation methods have potential and can be recommended in clinical scenarios. Whereas, 10 % Nisin and PDT with MTAD as chelator needs further inquiry.

Comparison of the effect and safety of Er:YAG laser combined with fluoride and methylene blue-photodynamic therapy on caries prevention

To compare the anti-caries effect and safety of Er:YAG laser combined with fluoride and methylene blue-photodynamic therapy (MB-PDT). A total of 28 rat dental caries models were established and randomly divided into seven groups: photodynamic therapy (PDT) group, laser combined with fluoride group, laser group, sodium fluoride group, and 0.9% saline control group. Spectrophotometric optical density was used to reflect the growth of Streptococcus mutans. Laser-induced fluorescence diagnostic (LF) instrument was utilized to detect the demineralization degree of dental caries. Histopathological sections were employed to observe the damage of dental pulp and buccal mucosa. The optical density (OD) value of the PDT and combination groups was significantly lower than that of other treatment groups (P<0.05). An increase in LF value and demineralization occurred in varying degrees with different treatment methods. Histopathological observation showed that pulp and buccal mucosa injury was more obvious in the combination group of 70 mw·cm⁻² and Er:YAG laser group compared with other groups. Under the same parameters, the combined group and PDT have good germicidal efficacy, but PDT has fewer adverse reactions and less damage. It is an effective and safe method for caries prevention.

Influence of resin cements and root canal disinfection techniques on the adhesive bond strength of fibre reinforced composite post to radicular dentin.

To determine the push out bond strength (PBS) of fibre reinforced composite post (FRCP) bonded to radicular dentin using different cement types total etch resin cement (TERC) and Self-adhesive resin cement (SARC) conditioned with (PDT, 5.25 % NaOCl with EDTA and 1% NaOCl) MATERIALS AND METHODS: Sixty freshly extracted (orthodontic purpose) human single rooted mandibular premolars were collected. Teeth were disinfected and coronal part of all samples were removed. Cleaning shaping and finishing of canal space was performed and filled with gutta percha via lateral condensation. Post space was prepared and disinfected with three irrigating solutions. Samples in group 1 and 2 disinfected 5.25 % NaOCl with EDTA, group 3 and 4 steriled with 1% NaOCl and group 5 and 6 disinfected with Methylene Blue photodynamic therapy (PDT). Based on the resin cement, FRCP was luted with TERC in group 2, 4 and 5; and with SARC in group 1,3 and 6 respectively. All specimens were subjected to aging and push-out bond strength (PBS) on universal testing machine after sectioning of each sample in three segments (coronal, middle and apical). Following push out bond strength (PBS), debonded surface were observed under stereomicroscope at 40x magnification. PBS were equated by means of analysis of variance (ANOVA) and Tukey's post hoc test maintaining level of significance (p < 0.05) RESULTS: Group 1 (SARC) and 2 (TERC) disinfected with 5.25 % NaOCl with 17 % EDTA, TERC (group 2) showed higher extrusion bond strength at all three levels coronal (9.25 ± 0.21 MPa) middle (8.81 ± 0.94 MPa) and apical (8.21 ± 0.93 MPa). Whereas, canal space sterilized with 1% NaOCl [group 3 (SARC) and group 4 (TERC)], posts cemented with TERC exhibited the higher PBS at all three levels of root canal (10.22 ± 0.36 MPa), (9.68 ± 0.51 MPa), (6.33 ± 0.08 MPa). Similarly, among PDT disinfected fiber post [group 5 (TERC) and group 6 (SARC)], TERC exhibited the greater PBS values at coronal, middle and apical levels (6.25 ± 0.39 MPa) (5.17 ± 0.22 MPa) (4.32 ± 0.69 MPa) compared to SARC specimens CONCLUSION: Irrespective of canal irrigant, fiber post bonded with TERC showed higher PBS at coronal and middle third. Fiber post bonded with SARC when irrigated with 5.25 % NaOCl with EDTA, 1% NaOCl displayed higher PBS at apical third. Canal disinfected using PDT showed lower PBS for FRCP compared to 5.25 % NaOCl with EDTA and 1% NaOCl.

Treatment of infected wounds with methylene blue photodynamic therapy: An effective and safe treatment method.

Bacterial resistance is a problem during the process of healing of infected wounds. As a therapy, photodynamic therapy (PDT) has broad-spectral antibacterial activity and non-selective action, which makes it possible to deal with antibiotic resistance.. Methylene blue is a commonly used medicine, but it is rarely used in clinical practice as a photosensitizer. The effect of methylene blue photodynamic therapy (MB-PDT) on infected wounds remains unclear. Our study aims to evaluate the safety and efficacy of MB-PDT on infected wounds. In this study, 5 patients with infected wounds were included, all of them were treated with MB-PDT by using the red LED which irradiated the wounds directly (635 nm, 120 J/cm2, 100 mW/cm2). The frequency and course of treatment were determined by the severity of the wound. After an average of 4 PDT session, infected wounds of all the patients healed.. The treatment also showed an excellent cosmetic effect. According to the follow-up periods of patients ranged from 3 to 12 months, there were no recurrences and side effects. MB-PDT has a great healing effect on infected wounds, and it is a safe, cheap and active clinical therapy.

Effects of Rose Bengal‐ and Methylene Blue‐Mediated Potassium Iodide‐Potentiated Photodynamic Therapy on Enterococcus faecalis: A Comparative Study

This study was performed to compare the use of methylene blue (MB) and rose bengal (RB) in antimicrobial photodynamic therapy (PDT) targeting Enterococcus faecalis (E. faecalis) bacteria in planktonic and biofilm forms with potassium iodide (KI) potentiation. E. faecalis bacteria in planktonic form were exposed to antimicrobial PDT protocols activating MB and RB, with or without KI potentiation, following laser irradiation with different exposure times, 60 mW/cm2 laser power, and different photosensitizer agent (PS)/potentiator concentrations to observe relationships among the variables. Two continuous-wave diode lasers were used for irradiation (red light: λ = 660 nm and green light: λ = 565 nm). The pre-irradiation time was 10 minutes. The vitality of E. faecalis biofilm was assessed by confocal laser scanning microscopy, and the morphology was determined by scanning electron microscopy. The effects on the proliferation of stem cells from the apical papilla (SCAPs) were analyzed by cell counting kit-8 assay. The staining effect of antimicrobial PDT on dentin slices was investigated. Statistical analysis using a one-way analysis of variance was done. KI-potentiated RB and MB antimicrobial PDT both effectively eradicated E. faecalis bacteria in planktonic and biofilm forms. The minimum bactericidal concentrations of PSs (±100 mM KI) were obtained through PDT on planktonic E. faecalis, and the optimal light parameters were 60 mW/cm2 , 6 J/cm2 for 100 seconds. KI-potentiated PDT effectively strengthened the ability to inhibit E. faecalis biofilm with 86.50 ± 5.78% for MB (P = 0.0015 < 0.01) and 91.50 ± 1.75% for RB (P = 0.0418 < 0.05) of bactericidal rate, with less toxicity for SCAPs (P < 0.001) and less staining. KI could reduce the staining induced by antimicrobial PDT on dentin slices. A combination of KI and antimicrobial PDT may be a useful alternative to conventional disinfection methods in endodontic treatment. MB and RB antimicrobial PDT at much lower concentrations with KI could hopefully achieve disinfection effects comparable with those of 1.5% NaClO while causing few adverse effects on SCAPs. KI helps to avoid staining problems associated with high concentrations of photosensitizer agents. Lasers Surg. Med. © 2020 Wiley Periodicals, LLC.

Methylene Blue Photodynamic Therapy Versus Tuberculin Purified Protein Derivative (PPD) Immunotherapy in Plane Warts in Children

Background: Plane warts are caused by human papilloma virus (HPV) (most often HPV‐2, HPV‐3 or HPV‐10) and generally multiple, slightly elevated, smooth papules occurring most often on the face, hands, neck, and legs of children and young adults. Objective: To compare the efficacy and safety daylight photodynamic therapy using methylene blue versus tuberculin purified protein derivative (PPD) immunotherapy intradermal injection in plane warts in children. Patients and methods: Forty patients (Children) complaining of plane warts were enrolled in this study. They were randomly selected from the attendants of out-patient clinic Dermatology and Venereology Department, Al Hussein University Hospital, Faculty of Medicine, Al-AzharUniversity from April 2019 to November 2019. Patients were divided randomly into two groups, to undergo either methylene blue day light photodynamic therapy (MB-DL PDT) or tuberculin PPD intradermally. Results: Tuberculin PPD-treated group showed significantly higher rates of complete response compared with MB- DL- PDT-treated group, complete response (60% versus 30% respectively); partial response (10% versus 30%), and no response (30% versus 40%). Conclusion: PPD intradermally and MB-DL PDT has significant advantages over other treatments. Most treatment modalities were painful, needing multiple visits (time and money consuming), and were directed to each individual wart. This study confirmed that immunotherapy tuberculin PPD and MB-DL-PDT can be used to treat cutaneous Plane warts in children.

Effect of methylene blue photodynamic therapy on human neutrophil functional responses

Photodynamic therapy (PDT) has become an emerging novel therapeutic approach for treating localized microbial infections, particularly those sustained by multidrug-resistant strains. Given the irreplaceable role played by professional phagocytes in limiting infections, such as polymorphonuclear neutrophils, any newly designed antimicrobial therapeutic approach must not interfere with their function. The present investigation presents a detailed analysis of the effect of PDT on the viability and several functional responses of human polymorphonuclear neutrophils loaded with methylene blue (MB), one of the more commonly used photosensitizers in antimicrobial PDT. Taking advantage of the use of a specifically-designed optical LED array for illuminating MB-loaded human polymorphonuclear neutrophils, a number of cell functions have been assayed under miniaturized, strictly controlled and reproducible experimental conditions. The major findings of this study are the following: (1) MB-PDT increases human neutrophils adhesion and does not modify myeloperoxidase release; (2) MB-PDT markedly enhances reactive oxygen species generation that is independent of superoxide-forming phagocytic oxidase and very likely ascribable to LED-dependent excitation of accumulated methylene blue; (3) MB-PDT almost abolishes human neutrophils candidacidal activity by hindering the engulfing machinery. This in vitro study may represent a valuable reference point for future research on PDT applications for treating localized microbial infections.

Methylene blue photodynamic therapy induces selective and massive cell death in human breast cancer cells

BackgroundBreast cancer is the main cause of mortality among women. The disease presents high recurrence mainly due to incomplete efficacy of primary treatment in killing all cancer cells. Photodynamic therapy (PDT), an approach that causes tissue destruction by visible light in the presence of a photosensitizer (Ps) and oxygen, appears as a promising alternative therapy that could be used adjunct to chemotherapy and surgery for curing cancer. However, the efficacy of PDT to treat breast tumours as well as the molecular mechanisms that lead to cell death remain unclear.MethodsIn this study, we assessed the cell-killing potential of PDT using methylene blue (MB-PDT) in three breast epithelial cell lines that represent non-malignant conditions and different molecular subtypes of breast tumours. Cells were incubated in the absence or presence of MB and irradiated or not at 640 nm with 4.5 J/cm2. We used a combination of imaging and biochemistry approaches to assess the involvement of classical autophagic and apoptotic pathways in mediating the cell-deletion induced by MB-PDT. The role of these pathways was investigated using specific inhibitors, activators and gene silencing.ResultsWe observed that MB-PDT differentially induces massive cell death of tumour cells. Non-malignant cells were significantly more resistant to the therapy compared to malignant cells. Morphological and biochemical analysis of dying cells pointed to alternative mechanisms rather than classical apoptosis. MB-PDT-induced autophagy modulated cell viability depending on the cell model used. However, impairment of one of these pathways did not prevent the fatal destination of MB-PDT treated cells. Additionally, when using a physiological 3D culture model that recapitulates relevant features of normal and tumorous breast tissue morphology, we found that MB-PDT differential action in killing tumour cells was even higher than what was detected in 2D cultures.ConclusionsFinally, our observations underscore the potential of MB-PDT as a highly efficient strategy which could use as a powerful adjunct therapy to surgery of breast tumours, and possibly other types of tumours, to safely increase the eradication rate of microscopic residual disease and thus minimizing the chance of both local and metastatic recurrence.

Synergism between fluconazole and methylene blue-photodynamic therapy against fluconazole-resistant Candida strains

Photodynamic therapy (PDT) has been proved to be effective against fungi and it may be employed as a coadjutant to conventional antifungal agents, leading to a more effective microbial control minimising side effects. This work evaluates the combined effect of PDT and fluconazole against resistant Candida albicans, Candida glabrata and Candida krusei. The yeasts were submitted to methylene blue-PDT (MB-PDT) in sub-inhibitory concentrations. In the present work, MB-PDT combined with fluconazole was more efficient in the inhibition of the C. albicans and C. glabrata than each treatment alone, being possible to infer that the treatments are synergic.

A study of the treatment of cutaneous fungal infection in animal model using photoactivated composite of methylene blue and gold nanoparticle

BackgroundOnychomycosis is a widespread public health problem, in which T. rubrum and T. mentagrophytes is the commenest causative organisms. Current medical therapy has many drawbacks and side effects. Methylene blue (m.b) photodynamic therapy (pdt) proved efficacy but with lengthy sessions. ObjectivesOptimizing methylene blue photodynamic therapy by combination of methylene blue photosensitizer and gold nanoparticles (aunps) in a composite as gold nanoparticles are efficient delivery systems and efficient enhancers of photosensitizers for antifungal photodynamic therapy. Materials and methodsEighty newzealand rabbit (Oryctolagus cuniculus) were used and categorized in eight equal groups as follows; healthy and infection control, composite photodynamic therapy and five comparative groups. Photodynamic therapy was initiated at day three to five post inoculation, for four sessions forty eight hours apart. Each group divided and light exposure at two fluencies; 80J and 100J. All groups were investigated macroscopically and microscopically (histopathology and scanning electron microscope) also flowcytometry assessment for cell death and X-ray analysis for gold nanoparticles accumulation in brain and liver tissues were determined. ResultsRecovery from infection approaching 96% in gold nanoparticles+light group, around 40% in methylene blue photodynamic therapy and 34% in composite photodynamic therapy. The observed findings confirmed by apparent decrease of apoptosis, however small amounts of gold nanoparticles detected in brain and liver. ConclusionLight stimulated gold nanoparticles is a promising tool in treatment of onychomycosis.