Photodynamic Therapy Can Be Effective as a Treatment for Herpes Simplex Labialis

Effects of photodynamic therapy in patients with infected skin ulcers: A meta-analysis

The purpose of the meta-analysis was to evaluate and compare the photodynamic therapy's effectiveness in treating infected skin wounds. The results of this meta-analysis were analysed, and the odds ratio (OR) and mean difference (MD) with 95% confidence intervals (CIs) were calculated using dichotomous or contentious random- or fixed-effect models. For the current meta-analysis, 6 examinations spanning from 2013 to 2021 were included, encompassing 154 patients with infected skin wounds were the used studies' starting point. Photodynamic therapy had a significantly lower wound ulcer size (MD, -4.42; 95% CI, -7.56--1.28, p = 0.006), better tissue repair (MD, -8.62; 95% CI, -16.76--0.48, p = 0.04) and lower microbial cell viability (OR, 0.13; 95% CI, 0.04-0.42, p < 0.001) compared with red light exposure in subjects with infected skin wounds. The examined data revealed that photodynamic therapy had a significantly lower wound ulcer size, better tissue repair and lower microbial cell viability compared with red light exposure in subjects with infected skin wounds. However, given that all examinations had a small sample size, consideration should be given to their values.

Combinations of Photodynamic Therapy with Other Minimally Invasive Therapeutic Technologies against Cancer and Microbial Infections

The rapid rise in research and development following the discovery of photodynamic therapy to establish novel photosensitizers and overcome the limitations of the technology soon after its clinical translation has given rise to a few significant milestones. These include several novel generations of photosensitizers, the widening of the scope of applications, leveraging of the offerings of nanotechnology for greater efficacy, selectivity for the disease over host tissue and cells, the advent of combination therapies with other similarly minimally invasive therapeutic technologies, the use of stimulus-responsive delivery and disease targeting, and greater penetration depth of the activation energy. Brought together, all these milestones have contributed to the significant enhancement of what is still arguably a novel technology. Yet the major applications of photodynamic therapy still remain firmly located in neoplasms, from where most of the new innovations appear to launch to other areas, such as microbial, fungal, viral, acne, wet age-related macular degeneration, atherosclerosis, psoriasis, environmental sanitization, pest control, and dermatology. Three main value propositions of combinations of photodynamic therapy include the synergistic and additive enhancement of efficacy, the relatively low emergence of resistance and its rapid development as a targeted and high-precision therapy. Combinations with established methods such as chemotherapy and radiotherapy and demonstrated applications in mop-up surgery promise to enhance these top three clinical tools. From published in vitro and preclinical studies, clinical trials and applications, and postclinical case studies, seven combinations with photodynamic therapy have become prominent research interests because they are potentially easily applied, showing enhanced efficacy, and are rapidly translating to the clinic. These include combinations with chemotherapy, photothermal therapy, magnetic hyperthermia, cold plasma therapy, sonodynamic therapy, immunotherapy, and radiotherapy. Photochemical internalization is a critical mechanism for some combinations.

Efficacy of 5-aminolevulinic acid-mediated photodynamic therapy in patients with nicotine stomatitis

AIM

This study aimed to treat smoker's palate (SP) using 5-aminolevulinic acid (5-ALA)-mediated photodynamic therapy (PDT).

METHODS

A total of 24 patients with SP were divided into two groups: group-I (test group; n = 12); and group-II (control group; n = 12). Group-I patients were treated with 5-ALA-mediated PDT, while group-II patients were advised to cease the smoking habit during the entire duration of the study and later. PDT was repeated on days 3, 7, and 14 (i.e., a total of four sittings including day 0 [baseline]). Later, the participants were called for follow-up after week-4 (1st follow-up), week-6 (2nd follow-up), and week-8 (3rd follow-up) after the completion of the treatment. The SPSS version 22.0 was used for data analysis.

RESULTS

Group-I patients showed a statistically significant improvement when all three time points were assessed (p < 0.0001). Similarly, the same trend was observed in the group-II participants (p < 0.001), however, the difference between both groups (i.e., group-I [test group] and group-II [control group]) was larger.

CONCLUSION

The findings of this clinical trial indicated a promising and satisfactory decrease in the clinical features of the smoker's palate without any adverse impacts utilizing 5-aminolevulinic acid-mediated photodynamic therapy. Hence, 5-ALA-mediated PDT appeared to be a promising treatment option together with smoking cessation.

Potential Use of Brazilian Green Propolis Extracts as New Photosensitizers for Antimicrobial Photodynamic Therapy against Cariogenic Microorganisms

The synergic effect of Streptococcus mutans and Candida albicans increases dental caries severity. Antimicrobial photodynamic therapy (aPDT) is a non-invasive treatment for antimicrobial aspects. However, the current photosensitizers (PS) have many downsides for dental applications. This study aimed to evaluate the efficiency of two different Brazilian green propolis (BGP-AF and BGP-AG) as PS for aPDT against these microorganisms. A single-species biofilm was irradiated with crude extracts and their fractions and controls. Such extracts showed the best results and were evaluated in dual-species biofilms. Photodegradation, reactive oxygen species (ROS), cytotoxicity, and color stability assays were also investigated. Reductions higher than 3 log₁₀ CFU/mL (p < 0.0001) occurred for crude BGP in single- and dual-species biofilms. Singlet oxygen was produced in BGP (p < 0.0001). BGP-mediated aPDT delayed S. mutans and C. albicans regrowth after 24 h of treatment (p < 0.0001). Both BGP did not change the color of dental materials (p > 0.05). BGP-AF-mediated aPDT showed 72.41% of oral keratinocyte viability (p < 0.0001). BGP extracts may be used in aPDT against S. mutans and C. albicans. Specifically, BGP-AF may represent a promising PS for dental applications.

Photodynamic therapy for treating infected skin wounds: A systematic review and meta-analysis from randomized clinical trials

BACKGROUND

Infected skin wounds represent a public health problem that effects 20 million people worldwide. Photodynamic therapy (PDT) is a treatment option with excellent results against several infections.

OBJECTIVE

This study aimed to perform a systematic review and meta-analysis on PDT efficacy for treating infected wounds based on randomized clinical trials (RCTs).

METHODS

PubMed, Scopus, Web of Science, SciELO, and the Cochrane library were searched. The Delphi List criteria and the Revised Cochrane risk-of-bias (Rob 2) were used for evaluating the quality of clinical trials. Meta-analyses were performed with the random-effect model. The odds ratio was the effect measure for binary outcomes, while the standard mean difference was used for continuous outcomes. The trim-and-fill method was used to detect small-study effects. The quality of evidence was verified for each outcome.

RESULTS

Only four out of 573 articles were selected for the qualitative and quantitative analyses. The most frequent cause of infected wounds was impaired venous circulation (75%). All studies used red LED light. PDT reduced healing time and improved the healing process and wound oxygenation. Patients treated with PDT showed 15% to 17% (p = 0.0003/ I²=0%) lower microbial cell viability in the wound and a significantly smaller wound size (0.72 cm²/p = 0.0187/I²=0%) than patients treated with placebo or red-light exposure. There was a high level of evidence for each meta-analysis outcome.

CONCLUSION

PDT can be an excellent alternative treatment for infected skin wounds, though larger trials are needed.

Mechanical and antibacterial efficacy of photo-sonodynamic therapy via methylene blue-loaded nanoparticles over dental implants for treating peri-implantitis

AIM

This study aimed to evaluate the mechanical (i.e., flexural modulus [FM], flexural strength [FS], and surface roughness [R_a]) and antibacterial efficacy of photo-sonodynamic therapy via methylene blue-loaded poly(D,L-lactide-co-glycolide) nanoparticles (MB-loaded PLGA NPs) over dental implants for potential treatment of peri-implantitis.

METHODS

PLGA NPs were synthesized via a solvent displacement method. After the synthesis and confirmation of MB-loaded PLGA NPs via physical (Scanning Electron Microscope [SEM]) and chemical characterization (Fourier transform infrared spectroscopy [FTIR]), the mature dental biofilm of Porphyromonas gingivalis was produced over the surfaces of dental implants. Then, the bacterial viability assessment of the following five study groups was performed: group-I (diode laser treatment); group-II (PDT/MB-loaded PLGA NPs treatment; group-III (ultrasound treatment); group-IV (ultrasound/PLGA NPs-MB treatment); and group-V: control group included the samples without any treatment. Finally, the FS, FM, and R_a of the samples was assessed.

RESULTS

Under the SEM, the NPs were spherical homogeneous particles having round morphology ranging approximately 100 nm in size without aggregation. The FTIR spectra of PLGA NPs and MB-loaded PLGA NPs demonstrated absorption peaks at approximately 1000 cm^-1 to 1200 cm^-1 and around 1500 cm^-1 to 1750 cm^-1. The greatest level of P. gingivalis killing was exhibited by ultrasound/MB-loaded PLGA-NPs-treated samples. The FS was statistically significantly greater for control group samples than any other group (i.e., 100.28 MPa; p<0.05). The FM and R_a ranged between 3.31 and 3.58 GPa and between 0.18 and 0.20 µm without any statistically significant difference between the control and experimental groups (p>0.05), respectively.

CONCLUSION

Within the limitations of this study, the application of photo-sonodynamic therapy via MB-loaded PLGA NPs demonstrated the greatest antibacterial activity against P. gingivalis without deteriorating the surfaces and compromising the mechanical properties of dental implants.

Photobiomodulation for Preventive Therapy of Recurrent Herpes Labialis: A 2-Year In Vivo Randomized Controlled Study

Objective: The present study aimed to evaluate the effectiveness of the application of photobiomodulation therapy (PBMT) in the prevention of recurrent herpes labialis (RHL) through a randomized controlled clinical trial. Background data: RHL is a lifelong infection that effects patients' quality of life. In the literature PBMT has shown positive results preventing RHL, decreasing recurrences and severity of lesions. Despite the good results reported, there are still few controlled clinical studies published on the subject. Methods: For this study, 158 volunteers were recruited and were randomly divided into three study groups: Laser 1-1 J/point (L1J): n = 61, Laser 2-2 J/point (L2J): n = 50, and placebo-0 J/point: n = 47. The treatment consisted of a protocol of 15 sessions throughout 6 months and 2 years of follow-up posttreatment. Results: The results showed that L1J presented the most satisfactory results concerning the reduction of the number of lesions per year and less severity of recurrences in the long-term evaluation when compared with L2J. Both Laser Groups (L1J and L2J) were statistically more efficient than placebo in all aspects analyzed. All patients who received laser treatment (L1J and L2J) and presented recurrences had significant improvement in frequency and/or severity of lesions. No patient had side effects from treatment. Conclusions: PBMT can be effective in the reduction of the frequency of recurrences of RHL and in the severity of postirradiation lesions that may appear.

Vitamin D and Vitamin D3 Supplementation during Photodynamic Therapy: A Review

Photodynamic therapy is an unconventional yet increasingly common method of treating dermatological diseases and cancer that is implemented more often in adults than in children. Current clinical uses include treatment of actinic keratosis, superficial basal cell carcinomas, and acne. Despite its high efficiency, photodynamic therapy support supplements have recently been reported in the literature, including calcitriol (1,25-dihydroxycholecalciferol), the active form of vitamin D, and vitamin D3 cholecalciferol. In clinical trials, photodynamic therapy enhanced with vitamin D or D3 supplementation has been reported for treatment of squamous cell skin cancers, actinic keratosis, and psoriasis. Experimental research on the effect of photodynamic therapy with vitamin D or D3 has also been carried out in breast cancer cell lines and in animal models. The aim of this review is to evaluate the usefulness and effectiveness of vitamin D and D3 as supports for photodynamic therapy. For this purpose, the Pubmed and Scopus literature databases were searched. The search keyword was: “vitamin D in photodynamic therapy”. In the analyzed articles (1979–2022), the authors found experimental evidence of a positive effect of vitamin D and D3 when used in conjunction with photodynamic therapy. An average of 6–30% (in one case, up to 10 times) increased response to photodynamic therapy was reported in combination with vitamin D and D3 as compared to photodynamic therapy alone. Implementing vitamin D and D3 as a supplement to photodynamic therapy is promising and may lead to further clinical trials and new clinical methodologies.

Photodynamic Inactivation of Microorganisms Using Semisynthetic Chlorophyll a Derivatives as Photosensitizers

In this study, we describe the semisynthesis of cost-effective photosensitizers (PSs) derived from chlorophyll a containing different substituents and using previously described methods from the literature. We compared their structures when used in photodynamic inactivation (PDI) against Staphylococcus aureus, Escherichia coli, and Candida albicans under different conditions. The PSs containing carboxylic acids and butyl groups were highly effective against S. aureus and C. albicans following our PDI protocol. Overall, our results indicate that these nature-inspired PSs are a promising alternative to selectively inactivate microorganisms using PDI.

Photodynamic Therapy Is Effective Against Candida auris Biofilms

Fungal infections are increasing in prevalence worldwide. The paucity of available antifungal drug classes, combined with the increased occurrence of multidrug resistance in fungi, has led to new clinical challenges in the treatment of fungal infections. Candida auris is a recently emerged multidrug resistant human fungal pathogen that has become a worldwide public health threat. C. auris clinical isolates are often resistant to one or more antifungal drug classes, and thus, there is a high unmet medical need for the development of new therapeutic strategies effective against C. auris. Additionally, C. auris possesses several virulence traits, including the ability to form biofilms, further contributing to its drug resistance, and complicating the treatment of C. auris infections. Here we assessed red, green, and blue visible lights alone and in combination with photosensitizing compounds for their efficacies against C. auris biofilms. We found that (1) blue light inhibited and disrupted C. auris biofilms on its own and that the addition of photosensitizing compounds improved its antibiofilm potential; (2) red light inhibited and disrupted C. auris biofilms, but only in combination with photosensitizing compounds; and (3) green light inhibited C. auris biofilms in combination with photosensitizing compounds, but had no effects on disrupting C. auris biofilms. Taken together, our findings suggest that photodynamic therapy could be an effective non-drug therapeutic strategy against multidrug resistant C. auris biofilm infections.

Effectiveness of photodynamic therapy as an adjunct to topical antiviral therapy in the treatment of herpes labialis: A randomized controlled clinical trial

BACKGROUND

The present clinical trial assessed the effectiveness of photodynamic therapy in association with topical acyclovir in the treatment of herpes labialis in adolescent patients.

MATERIALS AND METHODS

45 individuals with herpes labialis were divided into three groups on the basis of provision of treatment. (a) Group I: Topical acyclovir therapy (AVT) (n = 15, mean age: 17.5 years) (b) Group 2: photodynamic therapy (PDT) (n = 15, mean age:16.8 years) and (c) Group III: AVT + adjunctive PDT (n = 15, mean age: 17.0 years) respectively. HSV-1 quantification and pain scales [visual analogue scale (VAS) and McGill Pain Questionnaire (MPQ)] were calculated. Pro-inflammatory biomarkers including interleukin (IL-6) and tumor necrosis factor-alpha (TNF-α) were quantified using enzyme linked immunosorbent assay (ELISA). Shapiro-Wilk test was used to assess the normality. The Friedman test was employed to compute the comparison for changes recorded in pain scores, proinflammatory cytokines and HSV-1 quantification, whereas Mann-Whitney test was used to analyze the mean values and establish inter-group comparisons. All assessments were performed at baseline, immediate post op, 2-weeks, 4-weeks, 3-months, and 6-months.

RESULTS

A total of 44 individuals completed the clinical trial. According to the data obtained from the clinical assessment, all the study groups reported a decrease in the parameters being observed. However, Group III (anti-viral (acyclovir) therapy + adjunctive PDT) showed a statistically significant decrease, in comparison to Group II (PDT) and Group I [AVT] respectively. The quantified HSV-1 among all groups showed significant reduction among all groups at each successive follow-up. However, Group-III (AVT + PDT) showed statistically significant reduction as compared to Groups I and II, respectively (p < 0.05).

CONCLUSION

Topical anti-viral therapy with adjunctive PDT significantly helped in reducing the pain and pro-inflammatory biomarkers in adolescent herpes labialis patients.

Diseño e Implementación de un Sistema Bifrecuencial Basado en Láseres de Baja Potencia

El presente trabajo describe el diseño e implementación de un sistema bifrecuencial que puede ser usado como alternativa para el tratamiento de enfermedades en la boca mediante la irradiación de luz láser de baja potencia. El sistema es un prototipo, cuyo diseño mecánico es creado en un software de uso libre para luego ser impreso en un modelo 3D el cual alberga toda la parte electrónica y óptica. En cuanto a la parte electrónica, se monta sobre varios módulos los cuales cumplen diferentes funciones como son: el cargador de la batería, convertidores de potencia, drivers para los disparadores, una pantalla OLED que muestra información de los sensores, todo el proceso y mandos tanto manuales como automáticos son controlados por una tarjeta de desarrollo. El sistema óptico comprende de; un arreglo de espejos que básicamente dan el direccionamiento a la luz de los láseres y hacen que incidan sobre un mismo punto, al final se integra una fibra óptica para poder ingresar a partes inaccesibles en la boca para el tratamiento. Para validar el prototipo implementado, se realizaron mediciones tanto de la irradiancia como de la potencia en equipos especializados para estas aplicaciones, a más de basarse en revistas odontológicas y artículos de salud publicados por distintos institutos y universidades.

Utility of Photodynamic Therapy in Dentistry: Current Concepts

The significant growth in scientific and technological advancements within the field of dentistry has resulted in a wide range of novel treatment modalities for dentists to use. Photodynamic therapy (PDT) is an emerging, non-invasive treatment method, involving photosensitizers, light of a specific wavelength and the generation of singlet oxygen and reactive oxygen species (ROS) to eliminate unwanted eukaryotic cells (e.g., malignancies in the oral cavity) or pathogenic microorganisms. The aim of this review article is to summarize the history, general concepts, advantages and disadvantages of PDT and to provide examples for current indications of PDT in various subspecialties of dentistry (oral and maxillofacial surgery, oral medicine, endodontics, preventive dentistry, periodontology and implantology), in addition to presenting some images from our own experiences about the clinical success with PDT.

Treatment of herpes labialis by photodynamic therapy: Study protocol clinical trial (SPIRIT compliant)

BACKGROUND

Lesions of herpes labialis are caused by the herpes simplex virus type 1 and cause pain and aesthetic compromise. It is characterized by the formation of small vesicles that coalesce and rupture forming extremely painful ulcers, that evolve to crusts, dry desquamations until their complete remission. Currently the treatment of these lesions is done with acyclovir. Although it diminishes the symptomatology, it causes viral resistance and does not prevent the recurrence of the lesions. It is known that antimicrobial photodynamic therapy (aPDT) has numerous advantages, among them: the reduction of the time of remission, and does not cause resistance. This protocol will determine the effectiveness of PDT in lesions of herpes labialis.

MATERIALS AND METHODS

A total of 30 patients with herpes labialis in the prodromal stage of vesicles, ulcers, and crusts will be selected to participate in the study and randomized into 2 groups: G1 control and G2 experimental. After signing Research Ethics Committee and TA, patients in group G1 will undergo the standard gold treatment for herpes labialis with acyclovir and simulated PDT treatment. Patients in the experimental G2 group will be treated simulating the gold standard treatment of herpes labialis (placebo) and PDT. In all patients, saliva samples will be collected for analysis of cytokines, and will be performed exfoliative cytology in the lesions. The pain will be assessed through a pain scale and a questionnaire of quality of life related to oral health (OHIP-14) will be given to them. Patients will continue to be followed up after 7 days, 1 month, 3 months, and 6 months; if there is a recurrence of the lesion, they will contact the researchers.Clinical registration: clinicaltrials.gov - NCT04037475. Registered on July 2019.

Human alpha and beta herpesviruses and cancer: passengers or foes?

Based on seroepidemiological studies, human herpes simplex virus types 1 and 2 (HSV-1, HSV-2) are put in relation with a number of cancer diseases; however, they do not appear to play a direct role, being only considered cofactors. Their ability to transform the cells in vitro could be demonstrated experimentally by removing their high lytic ability by a certain dose of UV radiation or by photoinactivation in the presence of photosensitizers, such as neutral red or methylene blue, or culturing under conditions suppressing their lytic activity. However, recent studies indicate that UV irradiated or photoinactivated HSV-1 and HSV-2, able to transform non-transformed cells, behave differently in transformed cells suppressing their transformed phenotype. Furthermore, both transforming and transformed phenotype suppressing activities are pertaining only to non-syncytial virus strains. There are some proposed mechanisms explaining their transforming activity. According to the "hit and run" mechanism, viral DNA induces only initiation of transformation by interacting with cellular DNA bringing about mutations and epigenetic changes and is no longer involved in other processes of neoplastic progression. According to the "hijacking" mechanism, virus products in infected cells may activate signalling pathways and thus induce uncontrolled proliferation. Such a product is e.g. a product of HSV-2 gene designated ICP10 that encodes an oncoprotein RR1PK that activates the Ras pathway. In two cases of cancer, in the case of serous ovarian carcinoma and in some prostate tumours, virus-encoded microRNAs (miRNAs) were detected as a possible cofactor in tumorigenesis. And, recently described herpes virus-associated growth factors with transforming and transformation repressing activity might be considered important factors playing a role in tumour formation. And finally, there is a number of evidence that HSV-2 may increase the risk of cervical cancer after infection with human papillomaviruses. A similar situation is with human cytomegalovirus; however, here, a novel mechanism named oncomodulation has been proposed. Oncomodulation means that HCMV infects tumour cells and modulates their malignant properties without having a direct effect on cell transformation.

Ultrastructural Aspects of Photodynamic Inactivation of Highly Pathogenic Avian H5N8 Influenza Virus

Ultrastructural studies revealing morphological differences between intact and photodynamically inactivated virions can point to inactivation mechanisms and molecular targets. Using influenza as a model system, we show that photodynamic virus inactivation is possible without total virion destruction. Indeed, irradiation with a relatively low concentration of the photosensitizer (octacationic octakis(cholinyl) zinc phthalocyanine) inactivated viral particles (the virus titer was determined in Madin Darby Canine Kidney (MDCK) cells) but did not destroy them. Transmission electron microscopy (TEM) revealed that virion membranes kept structural integrity but lost their surface glycoproteins. Such structures are known as “bald” virions, which were first described as a result of protease treatment. At a higher photosensitizer concentration, the lipid membranes were also destroyed. Therefore, photodynamic inactivation of influenza virus initially results from surface protein removal, followed by complete virion destruction. This study suggests that photodynamic treatment can be used to manufacture “bald” virions for experimental purposes. Photodynamic inactivation is based on the production of reactive oxygen species which attack and destroy biomolecules. Thus, the results of this study can potentially apply to other enveloped viruses and sources of singlet oxygen.

Trends and targets in antiviral phototherapy

Photodynamic therapy (PDT) is a well-established treatment option in the treatment of certain cancerous and pre-cancerous lesions. Though best-known for its application in tumor therapy, historically the photodynamic effect was first demonstrated against bacteria at the beginning of the 20^th century. Today, in light of spreading antibiotic resistance and the rise of new infections, this photodynamic inactivation (PDI) of microbes, such as bacteria, fungi, and viruses, is gaining considerable attention. This review focuses on the PDI of viruses as an alternative treatment in antiviral therapy, but also as a means of viral decontamination, covering mainly the literature of the last decade. The PDI of viruses shares the general action mechanism of photodynamic applications: the irradiation of a dye with light and the subsequent generation of reactive oxygen species (ROS) which are the effective phototoxic agents damaging virus targets by reacting with viral nucleic acids, lipids and proteins. Interestingly, a light-independent antiviral activity has also been found for some of these dyes. This review covers the compound classes employed in the PDI of viruses and their various areas of use. In the medical area, currently two fields stand out in which the PDI of viruses has found broader application: the purification of blood products and the treatment of human papilloma virus manifestations. However, the PDI of viruses has also found interest in such diverse areas as water and surface decontamination, and biosafety.

Effect of photodynamic therapy by 810 and 940 nm diode laser on Herpes Simplex Virus 1: An in vitro study

INTRODUCTION

Herpes simplex virus (HSV) is among the most common viruses in humans. HSV1 is often responsible for oral and perioral herpetic lesions. Photodynamic therapy (PDT) is a novel antimicrobial modality that involves the use of laser and a photosensitizer with a specific wavelength. This study aimed to assess and compare the effect of PDT with 810 and 940 nm diode laser and indocyanine green (ICG) photosensitizer on HSV1.

METHODS

In this in vitro study, HSV1 isolated from herpes labialis and there were 6 experimental groups.The irradiation parameters were the same for all groups. Number of remaining viruses per milliliter in each group was determined using real-time polymerase chain reaction (PCR) and statistically analyzed by ANOVA.

RESULTS

The virus count in all groups significantly decreased compared to the control group (P < 0.05) except in group ICG- without irradiation (P > 0.05). Comparison of groups 810- and 940- (use of each laser alone) with groups 810+ and 940+ (use of each laser plus ICG) revealed that reduction in virus count in groups 810+ and 940+ was significantly greater than that in groups 810- and 940-.

CONCLUSION

810 nm diode laser irradiation and ICG causes the greatest reduction in number of HSV1 compared to all the other groups. ICG without laser irradiation has not significant efficacy on reduction of virus count.

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.

Comparing the effect of diode laser against acyclovir cream for the treatment of herpes labialis

Background

Recently alternative therapies such as the use of diode laser therapy have been introduced for recurrent herpes labial infection. The aim of this study was to evaluate the effectiveness of diode laser for treatment of recurrent herpes labialis.

Material and Methods

This was single-blind randomized clinical trial to evaluate the efficacy of diode laser for the treatment of recurrent herpes labial. In total, 60 patients whit recurrent herpes simplex labialis were selected and randomly divided in to three groups. 20 patients received treatment whit diode laser (at a wavelength of 870 nm, energy density 4.5 j/cm2), 20 patients were treated with acyclovir cream 5%, 20 patients received treatment with laser-off (placebo). The end point was lesions crusting. Data analyzed by Tukey HSD Test and One-way ANOVA (at a significance level of 0.05) in SPSS-20 software.

Results

The mean length of recovery time (day) in the laser, off laser, and acyclovir groups was 2.20±0.41, 4.30±1.03, and 3.4±1.142, respectively. There is a significant difference between three groups in this regard (P<0.0001). The mean duration of pain (day) was 1.35±0.74, 2.65±1.27, and 2.30±0.92 for laser, off laser, and acyclovir groups, respectively (P<0.0001).

Conclusions

Treatment with diode laser reduced the length of recovery time and pain severity faster than treatment with acyclovir cream.

Key words:Recurrent herpes labial, Acyclovir, Low level laser therapy.

The potential of photodynamic therapy (PDT)-Experimental investigations and clinical use

Photodynamic therapy (PDT) is an intensively studied part of medicine based on free radicals. These reactive species, extremely harmful for whole human organism, are used for eradication numerous diseases. Specific structure of ill tissues causes accumulation free radicals inside them without attack remaining healthy tissues. A rapid development of medicine and scientific research has led to extension of PDT towards treatment many diseases such as cancer, herpes, acne and based on antimicrobials. The presented review article is focused on the aforementioned disorders with accurate analysis of the newest available scientific achievements. The discussed cases explicitly indicate on high efficacy of the therapy. In most cases, free radicals turned out to be solution of many afflictions. Photodynamic therapy can be considered as promising treatment with comparable effectiveness but without side effects characteristic for chemotherapy.

Light based anti-infectives: ultraviolet C irradiation, photodynamic therapy, blue light, and beyond

Owing to the worldwide increase in antibiotic resistance, researchers are investigating alternative anti-infective strategies to which it is supposed microorganisms will be unable to develop resistance. Prominent among these strategies, is a group of approaches which rely on light to deliver the killing blow. As is well known, ultraviolet light, particularly UVC (200-280 nm), is germicidal, but it has not been much developed as an anti-infective approach until recently, when it was realized that the possible adverse effects to host tissue were relatively minor compared to its high activity in killing pathogens. Photodynamic therapy is the combination of non-toxic photosensitizing dyes with harmless visible light that together produce abundant destructive reactive oxygen species (ROS). Certain cationic dyes or photosensitizers have good specificity for binding to microbial cells while sparing host mammalian cells and can be used for treating many localized infections, both superficial and even deep-seated by using fiber optic delivered light. Many microbial cells are highly sensitive to killing by blue light (400-470 nm) due to accumulation of naturally occurring photosensitizers such as porphyrins and flavins. Near infrared light has also been shown to have antimicrobial effects against certain species. Clinical applications of these technologies include skin, dental, wound, stomach, nasal, toenail and other infections which are amenable to effective light delivery.

In vitro evaluation of the oxidation efficacy of transgingival photodynamic therapy

OBJECTIVE

To evaluate the capability of soft laser light to penetrate blood, serum, gingival connective tissue and pure collagen type I.

MATERIALS AND METHODS

A 1:1 mixture of methylene blue (MB) and diphenylisobenzofuran (DPBF) was irradiated for 60 s with a diode laser (670 nm, 0.3 W) through blood, serum, gingival connective tissue and collagen type I (2 mm transillumination thickness). The oxidation of DPBF by MB was determined spectrophotometrically by measuring the optical density (oD) at 410 nm. The absorption spectra of DPBF/MB irradiated through MB (1%) and strawberry red solution (3%) served as control.

RESULTS

The mean oD of non-irradiated DPBF/MB was 1.98 ± 0.04. Irradiation through MB showed no oxidation of DPBF (1.98 ± 0.02; p > 0.05), while interposition of strawberry red and serum resulted in almost complete oxidation of DPBF (0.13 ± 0.09, 0.06 ± 0.03; p ≤ 0.0001). Irradiation through gingiva and collagen reduced the oxidation of DPBF significantly (1.0 ± 0.04, 0.7 ± 0.04; p ≤ 0.0001), accounting for 50% to 35% of the non-irradiated DPBF/MB solution.

CONCLUSION

Red light from a diode laser can penetrate blood and gingival tissues. However, light absorption for collagen and connective tissue can hamper the oxidation process.

Evaluation of the efficacy of low-level light therapy using 1072 nm infrared light for the treatment of herpes simplex labialis

BACKGROUND

Recent research has shown that low-level light therapy (LLLT) using 1072 nm infrared light is effective in reducing the duration of herpes simplex labialis (HSL) episodes and enhancing the healing process.

METHODS

This was a prospective, randomized, placebo-controlled, clinical trial to evaluate the efficacy of a 1072 nm light-emitting diode device for the treatment of HSL. In total, 87 patients with recurrent HSL were recruited and randomly divided into two groups. Subjects received a 3-min treatment with either 1072 nm infrared light therapy or placebo (sham) light therapy three times/day for 2 days. The devices used for both groups were identical in appearance and could not be differentiated by volunteers or researchers, and 1072 nm light is invisible to the human eye. The primary endpoint was healing time, which was taken as the time for the HSL lesions to resolve fully and for the underlying skin to become completely re-epithelialized, and the secondary endpoint was lesion crusting.

RESULTS

The median time to healing for the active group was 129 h, compared with 177 h for the control group, which was significant (P = 0.01). There was no difference between the two groups for median time to lesion crusting (P = 0.66).

CONCLUSIONS

Compared with placebo treatment, the treatment of HSL lesions with 1072 nm infrared light significantly reduced healing time.

Laser treatment of recurrent herpes labialis: a literature review

Recurrent herpes labialis is a worldwide life-long oral health problem that remains unsolved. It affects approximately one third of the world population and causes frequent pain and discomfort episodes, as well as social restriction due to its compromise of esthetic features. In addition, the available antiviral drugs have not been successful in completely eliminating the virus and its recurrence. Currently, different kinds of laser treatment and different protocols have been proposed for the management of recurrent herpes labialis. Therefore, the aim of the present article was to review the literature regarding the effects of laser irradiation on recurrent herpes labialis and to identify the indications and most successful clinical protocols. The literature was searched with the aim of identifying the effects on healing time, pain relief, duration of viral shedding, viral inactivation, and interval of recurrence. According to the literature, none of the laser treatment modalities is able to completely eliminate the virus and its recurrence. However, laser phototherapy appears to strongly decrease pain and the interval of recurrences without causing any side effects. Photodynamic therapy can be helpful in reducing viral titer in the vesicle phase, and high-power lasers may be useful to drain vesicles. The main advantages of the laser treatment appear to be the absence of side effects and drug interactions, which are especially helpful for older and immunocompromised patients. Although these results indicate a potential beneficial use for lasers in the management of recurrent herpes labialis, they are based on limited published clinical trials and case reports. The literature still lacks double-blind controlled clinical trials verifying these effects and such trials should be the focus of future research.

Note: design of a dose-controlled phototherapy system based on hyperspectral studies

Phototherapy consists in applying radiation on a part of the human body in order to treat an illness. A radiation dose is established for each treatment. In order to apply the correct dose a treatment time is set. However, in this work we have carried out some hyperspectral imaging studies that conclude that the radiation sources and the absorption properties of each patient can change. Therefore, the same treatment time does not ensure that the patient receive the appropriate dose. Thus, an optimized therapy system must measure the radiation emitted by the source and absorbed by the patient on real time to calculate the optimal dose at which the treatment is effective. In this work, we have developed and designed a custom system to measure the effectiveness of a radiative therapy treatment to adapt the appropriate dose for a specific patient in real time.

In vitro photodynamic therapy against Foncecaea pedrosoi and Cladophialophora carrionii

Photodynamic therapy (PDT) has been originally developed for cancer treatment, but recently, it has been successfully employed against microorganisms, including fungi. Chromoblastomycosis is a subcutaneous fungal infection that is recalcitrant to conventional antifungal drug therapy. The most frequent species involved are Foncecaea pedrosoi and Cladophialophora carrionii. The present study aimed to verify the efficacy in vitro of PDT employing methylene blue (MB) as a photosensitiser and Light emmiting diode (LED) (InGaAl) as the light source. Methylene blue at the concentrations of 16, 32 and 64 μg/mL and LED (InGalP) were employed for 15 min against spores of two isolates of F. pedrosoi and two isolates of C. carrionii. The spores were plated on Sabouraud Dextrose agar and the number of colony forming units was counted after 7-10 days of incubation at 37 °C. The PDT with MB and LED was efficient in reducing the growth of all samples tested. Better results were obtained for the concentration of 32 μg/mL of MB. The treatment proved to be highly effective in killing the samples of F. pedrosoi and Cladophialophora pedrosoi tested in vitro. PDT arises as a promising alternative for the treatment of this subcutaneous infection.

Decontamination of dental implant surfaces by means of photodynamic therapy

Several implant surface debridement methods have been reported for the treatment of peri-implantitis, however, some of them can damage the implant surface or promote bacterial resistance. Photodynamic therapy (PDT) is a new treatment option for peri-implantitis. The aim of this in vitro study was to analyze implant surface decontamination by means of PDT. Sixty implants were equally distributed (n = 10) into four groups and two subgroups. In group G1 there was no decontamination, while in G2 decontamination was performed with chlorhexidine. G3 (PDT − laser + dye) and G4 (laser, without dye) were divided into two subgroups each; with PDT performed for 3 min in G3a and G4a, and for 5 min in G3b and G4b. After 5 min in contact with methylene blue dye (G3), the implants were irradiated (G3 and G4) with a low-level laser (GaAlAs, 660 nm, 30 mW) for 3 or 5 min (7.2 and 12 J). After the dilutions, culture media were kept in an anaerobic atmosphere for 1 week, and then colony forming units were counted. There was a significant difference (p < 0.001) between G1 and the other groups, and between G4 in comparison with G2 and G3. Better decontamination was obtained in G2 and G3, with no statistically significant difference between them. The results of this study suggest that photodynamic therapy can be considered an efficient method for reducing bacteria on implant surfaces, whereas laser irradiation without dye was less efficient than PDT.

Photodynamic inactivation of mammalian viruses and bacteriophages

Photodynamic inactivation (PDI) has been used to inactivate microorganisms through the use of photosensitizers. The inactivation of mammalian viruses and bacteriophages by photosensitization has been applied with success since the first decades of the last century. Due to the fact that mammalian viruses are known to pose a threat to public health and that bacteriophages are frequently used as models of mammalian viruses, it is important to know and understand the mechanisms and photodynamic procedures involved in their photoinactivation. The aim of this review is to (i) summarize the main approaches developed until now for the photodynamic inactivation of bacteriophages and mammalian viruses and, (ii) discuss and compare the present state of the art of mammalian viruses PDI with phage photoinactivation, with special focus on the most relevant mechanisms, molecular targets and factors affecting the viral inactivation process.

Local clinical phototreatment of herpes infection in São Paulo

The clinical use of topical photodynamic therapy in herpes simplex lesions in São Paulo is presented and discussed. Although previous attempts utilising this type of approach in the USA were discontinued in the early 1970s due to several presentations of post-treatment Bowen's disease, none of the cases from the clinic presented here have displayed any complications on follow-up. In addition, lesion recrudescence periods are generally much longer than with conventional approaches. This is thought to be due to improvements in the treatment protocol, viz. use of the non-toxic photosensitisers methylene blue and Hypericum perforatum extract in place of proflavine and neutral red in the original trials, differences in photosensitisation pathway and illumination of the treatment site with red rather than fluorescent/UV light. Post-treatment cosmesis is also excellent.

Clinical use of photodynamic antimicrobial chemotherapy for the treatment of deep carious lesions

The purpose of this study was to assess photodynamic antimicrobial chemotherapy (PACT) via irradiation, using a low power laser associated with a photosensitization dye, as an alternative to remove cariogenic microorganisms by drilling. Remaining dentinal samples in deep carious lesions on permanent molars (n = 26) were treated with 0.01% methylene blue dye and irradiated with a low power laser (InGaAIP - indium gallium aluminum phosphide; λ = 660 nm; 100 mW; 320 Jcm(-2); 90 s; 9J). Samples of dentin from the pulpal wall region were collected with a micropunch before and immediately after PACT and kept in a transport medium for microbiological analysis. Samples were cultured in plates of Brucella blood agar, Mitis Salivarius Bacitracin agar and Rogosa SL agar to determine the total viable bacteria, mutans streptococci and Lactobacillus spp. counts, respectively. After incubation, colony-forming units were counted and microbial reduction was calculated for each group of bacteria. PACT led to statistically significant reductions in mutans streptococci (1.38 log), Lactobacillus spp. (0.93 log), and total viable bacteria (0.91 log). This therapy may be an appropriate approach for the treatment of deep carious lesions using minimally invasive procedures.

Photodynamic therapy mediated by methylene blue dye in wound healing

OBJECTIVE

We sought to investigate the wound-healing process after photodynamic therapy (PDT) mediated by methylene blue dye (MB).

BACKGROUND DATA

Few scientific studies show the PDT roles in wound healing.

MATERIALS AND METHODS

One hundred rats were given a circular wound on the back, inflicted with a 6-mm-diameter punch. The animals were divided into four groups: control (no treatment); dye (topical application of MB); laser (InGaAlP, 117.85 J/cm(2), 100 mW, 660 nm, single point); and PDT (topical application of MB followed by laser irradiation). After 1, 3, 5, 7, and 14 days, the cutaneous wounds were photographed and assessed with histopathologic examination by using light microscope. Changes seen in edema, necrosis, inflammation, granulation tissue, re-epithelialization, and number of young fibroblasts were semiquantitatively evaluated. The wound-area changes were measured with special software and submitted to statistical analysis.

RESULTS

The laser group demonstrated the smallest wound area at 14 days after the surgical procedure (p < 0.01). Concerning complete re-epithelialization, the laser group showed it at 5-7 days after surgery, whereas the PDT and the other groups showed it at 14 days.

CONCLUSIONS

Laser interaction with tissue is somehow changed when exposed to the MB. PDT mediated by MB was not prejudicial to wound healing, as no delay occurred compared with the control group.

High-intensity laser and photodynamic therapy as a treatment for recurrent herpes labialis

OBJECTIVE

The aim of this study was to report the treatment of recurrent herpes labialis (RHL) using a high-intensity laser or methylene blue (MB)-mediated photodynamic therapy (PDT) in combination with low-level laser therapy (LLLT).

MATERIALS AND METHODS

Four clinical cases of patients diagnosed with RHL are described in this report. Two patients were subjected to high-intensity laser therapy (HILT) followed by LLLT, and two patients received MB-mediated PDT, again followed by LLLT. LLLT was conducted at 24, 48, 72 h, and 7 d after HILT or PDT. Patients were followed up after 6 mo.

RESULTS

Throughout the follow-up period, all patients reported pain relief and did not show any signs or symptoms of RHL. A favorable healing process was observed in all cases. None of the patients reported pain as a consequence of the treatment.

CONCLUSION

These results suggest that HILT and MB-mediated PDT, in combination with LLLT, may constitute a benefit when treating vesicles in RHL.

Development and applications of photo-triggered theranostic agents

Theranostics, the fusion of therapy and diagnostics for optimizing efficacy and safety of therapeutic regimes, is a growing field that is paving the way towards the goal of personalized medicine for the benefit of patients. The use of light as a remote-activation mechanism for drug delivery has received increased attention due to its advantages in highly specific spatial and temporal control of compound release. Photo-triggered theranostic constructs could facilitate an entirely new category of clinical solutions which permit early recognition of the disease by enhancing contrast in various imaging modalities followed by the tailored guidance of therapy. Finally, such theranostic agents could aid imaging modalities in monitoring response to therapy. This article reviews recent developments in the use of light-triggered theranostic agents for simultaneous imaging and photoactivation of therapeutic agents. Specifically, we discuss recent developments in the use of theranostic agents for photodynamic-, photothermal- or photo-triggered chemotherapy for several diseases.