Mechanisms of PhotoBioModulation (PBM) focused on oral mucositis prevention and treatment: a scoping review

A novel investigational preclinical model to assess fluence rate for dental oral craniofacial tissues

OBJECTIVE

Photodynamic Therapy (PDT) and Photobiomodulation (PBM) are recognized for their potential in treating head and neck conditions. The heterogeneity of human tissue optical properties presents a challenge for effective dosimetry. The porcine mandible cadaver serves as an excellent model and has several similarities to human tissues of the dental oral craniofacial complex. This study aims to validate a novel modeling system that will help refine PDT and PBM dosimetry for the head and neck region.

METHODS AND MATERIALS

Light transmission was analyzed through several tissue combinations at distances of 2 mm to 10 mm. Maximum light fluence rates (mW/cm2) were compared across tissue types to reveal the effects of tissue heterogeneity.

RESULTS

The study revealed that light fluence is affected by tissue composition, with dentin/enamel showing reduced transmission and soft tissue regions exhibiting elevated values. The porcine model has proven to be efficient in mimicking human tissue responses to light, enabling the potential to optimize future protocols.

CONCLUSION

The porcine mandible cadaver is a novel model to understand the complex interactions between light and tissue. This study provides a foundation for future investigations into dosimetry optimization for PDT and PBM.

The power of light - From dental materials processing to diagnostics and therapeutics

Harnessing the power of light and its photonic energy is a powerful tool in biomedical applications. Its use ranges from biomaterials processing and fabrication of polymers to diagnostics and therapeutics. Dental light curable materials have evolved over several decades and now offer very fast (≤ 10 s) and reliable polymerization through depth (4-6 mm thick). This has been achieved by developments on two fronts: (1) chemistries with more efficient light absorption characteristics (camphorquinone [CQ], ~30 L mol-1 cm1 [ʎmax 470 nm]; monoacylphosphine oxides [MAPO], ~800 L mol-1 cm-1 [ʎmax 385 nm]; bisacylphosphine oxide [BAPO], ~1,000 L mol-1 cm-1 [ʎmax 385 nm]) as well mechanistically efficient and prolonged radical generation processes during and after light irradiation, and; (2) introducing light curing technologies (light emitting diodes [LEDs] and less common lasers) with higher powers (≤ 2 W), better spectral range using multiple diodes (short: 390-405 nm; intermediate: 410-450 nm; and long: 450-480 nm), and better spatial power distribution (i.e. homogenous irradiance). However, adequate cure of materials falls short for several reasons, including improper selection of materials and lights, limitations in the chemistry of the materials, and limitations in delivering light through depth. Photonic energy has further applications in dentistry which include transillumination for diagnostics, and therapeutic applications that include photodynamic therapy, photobiomodulation, and photodisinfection. Light interactions with materials and biological tissues are complex and it is important to understand the advantages and limitations of these interactions for successful treatment outcomes. This article highlights the advent of photonic technologies in dentistry, its applications, the advantages and limitations, and possible future developments.

Antimicrobial research of carbohydrate polymer- and protein-based hydrogels as reservoirs for the generation of reactive oxygen species: A review

Reactive oxygen species (ROS) play an important role in biological milieu. Recently, the rapid growth in our understanding of ROS and their promise in antibacterial applications has generated tremendous interest in the combination of ROS generators with bulk hydrogels. Hydrogels represent promising supporters for ROS generators and can locally confine the nanoscale distribution of ROS generators whilst also promoting cellular integration via biomaterial-cell interactions. This review highlights recent efforts and progress in developing hydrogels derived from biological macromolecules with embedded ROS generators with a focus on antimicrobial applications. Initially, an overview of passive and active antibacterial hydrogels is provided to show the significance of proper hydrogel selection and design. These are followed by an in-depth discussion of the various approaches for ROS generation in hydrogels. The structural engineering and fabrication of ROS-laden hydrogels are given with a focus on their biomedical applications in therapeutics and diagnosis. Additionally, we discuss how a compromise needs to be sought between ROS generation and removal for maximizing the efficacy of therapeutic treatment. Finally, the current challenges and potential routes toward commercialization in this rapidly evolving field are discussed, focusing on the potential translation of laboratory research outcomes to real-world clinical outcomes.

Photobiomodulation effects on fibroblasts and keratinocytes after ionizing radiation and bacterial stimulus

OBJECTIVE

Photobiomodulation therapy (PBMT) has proven to reduce inflammation and pain and increase wound healing. Thus, the aim of this study was to analyze the effects of PBMT parameters on migration, proliferation, and gene expression after ionizing radiation and bacterial-induced stress in an in vitro study.

DESIGN

Keratinocytes (HaCaT) and Fibroblasts (HGFs) were grown in DMEM with 10 % fetal bovine serum until stressful condition induction with lipopolysaccharide (LPS) of Escherichia coli (1 µg/mL), Porphyromonas gingivalis protein extract (5 µg/mL) and ionizing radiation (8 Gy). Low-laser irradiation (660 nm, 30 mW) was carried out in four sessions, with 6 h intervals, and energy density of 2, 3, 4, and 5 J/cm². Scratch assays, immunofluorescence, and RT-qPCR were performed.

RESULTS

Treated fibroblasts and keratinocytes showed significant response in proliferation and migration after scratch assays (p < 0.05). Higher expressions of α-SMA in fibroblasts and F-actin in keratinocytes were observed in cells subjected to 3 J/cm². PI3K-pathway genes expression tended to enhance in fibroblasts, presenting a higher relative expression when compared to keratinocytes. In keratinocytes, PBMT groups demonstrated deregulated expression for all inflammatory cytokines' genes tested while fibroblasts presented a tendency to enhance those genes expression in a dose dependent way.

CONCLUSIONS

The present study showed that delivering 660 nm, 30 mW was effective to stimulate cell migration, proliferation and to accelerate wound healing. PBMT can modulate cytokines and pathways involved in wound repair. The different energy densities delivering distinct responses in vitro highlights that understanding laser parameters is fundamental to improve treatment strategies.

Photobiomodulation effect of infra-red laser on the level of gonad maturity in the Simese Catfish (Pangasianodon hypophthalmus)

The purpose of this study is to determine how photo biomodulation therapy utilizing infrared diode laser irradiation (975.2 nm) affects the gonadal maturity level (GML) of male Siamese catfish (Pan-gasianodon hypothalamus). The interest in applying laser therapy in medicine and dentistry has remarkably increased in the last decade. Different types of lasers are available, and their usage is well-defined by different parameters, such as wavelength, energy density, power output, duration of radiation, power density and radiation mode. Infrared diode laser irradiation is used at the reproductive point (governor's vessel), situated 2/3 of the way between the anus and the pectoral fin. This study examined the metrics GML, gonads somatic index, and hepatosomatic index. The treatments were Control+ (ovaprim), Control- (without the treatment), P1 (0.2 J/cm2), P2 (0.4 J/cm2), P3 (0.6 J/cm2), and P4 (0.8 J/cm2). Therapy with infrared diode laser irradiation can modify gonad maturity (GML), gonadosomal index, and hepatosomatic index in male Siamese catfish. The photobiomodulation effect of an infrared laser stimulated the gonadal maturation of Siamese catfish. This is based on the values of wavelength (nm), power (mW), beam area (cm2), time (s), radiation mode (rad) and energy dose (J/cm2) in Control- (no treatment), control+ (ovaprim), P1, P2, P3, and P4. The increase in the observed parameter values is due to the vitellogenesis process. The fish gonads at the GML IV had the highest GML at P2 (dose 0.4 J/cm2), with a GSI value of 1.02% and an HSI value of 1.46%. According to the study's findings, photo biomodulation therapy with infrared diode laser exposure at a dose of 0.4 J/cm2 is the best way to increase the gonad maturity of male Siamese catfish.

Monte Carlo based dosimetry of extraoral photobiomodulation for prevention of oral mucositis

Photobiomodulation therapy (PBMT) is recommended for prevention and treatment of oral mucositis, a painful condition that occurs in cancer patients. Intraoral PBMT is limited to treating distal oral mucosa and oropharynx. Extraoral PBMT may provide a more efficient intervention. The goal of this study was to develop a clinically viable protocol for extraoral PBMT. Monte Carlo modeling was used to predict the distribution of 850 nm light for four treatment sites, using anatomical data obtained from MRI and optical properties from the literature. Simulated incident light power density was limited to 399 mW/cm2 to ensure treatment safety and to prevent tissue temperature increase. The results reveal that total tissue thickness determines fluence rate at the oral mucosa, whereas the thickness of individual tissue layers and melanin content are of minor importance. Due to anatomical differences, the fluence rate varied greatly among patients. Despite these variations, a universal protocol was established using a median treatment time methodology. The determined median treatment times required to deliver efficacious dose between 1 and 6 J/cm2 were within 15 min. The developed PBMT protocol can be further refined using the combination of pretreatment imaging and the Monte Carlo simulation approach implemented in this study.

Proposal of a prophylactic photobiomodulation protocol for chemotherapy-induced oral and oropharyngeal mucositis: a randomized clinical trial

Photobiomodulation therapy (PBMT) is widely used in oncology settings, but lack of assessment standardization is the main barrier to optimization of clinical protocols. This study analyzed three PBMT protocols for preventing oral and oropharyngeal mucositis (OM) in patients undergoing chemotherapy (CT) and/or hematopoietic stem cell transplantation (HSCT). This is a preliminary randomized blind clinical trial. Group 1 received intraoral prophylactic PBMT, Group 2 received intraoral and oropharyngeal PBMT, and Group 3 received intraoral, oropharyngeal, and extraoral PBMT. The applications were from the first day of CT to day + 10. Clinicodemographic data, CT regimens, types of HSCT, hematological exams, occurrence/severity of OM, odynophagia, and OM-related opportunistic infections were assessed. Sixty participants (age range: 18-74 years) were included; 70% of them underwent CT and 30% HSCT. About 43.3% of patients had OM, while odynophagia was reported by 23.3%. Both Groups 1 and 2 revealed better results. Multivariate analysis showed that HSCT directly influenced the occurrence of OM. Individuals who had undergone allogeneic HSCT were 1.93 times more likely to develop OM (p < 0.001). Group 3 exhibited a higher frequency of OM, albeit of lower grades. This group consisted of half the population who had undergone HSCT, had the highest percentage of melphalan use, and had the lowest mean leukocyte count. The three proposed protocols were effective in preventing and reducing OM, with good tolerance and no reported adverse effects. PBMT is a safe and effective approach to OM prophylaxis in adults undergoing CT/HSCT.

Therapeutic Outcomes of Photobiomodulation in Cancer Treatment-induced Oral Mucositis: A Systematic Review

Background

This systematic review was performed to analyze the therapeutic efficacy of photobiomodulation (PBM) in managing oral mucositis (OM) that appears in this context.

Material and Methods

The search strategy of the systematic review was conducted according to PRISMA guidelines. The eligibility criteria according to PICO process has been defined as follows: Population (P): adult patients with head and neck cancer; Intervention (I): PBM; Comparison (C): placebo group; Outcome (O): pain, oral quality of life (QoL), evolution of the grade OM and pain. The set criteria for inclusion were peer-reviewed articles.

Results

The following database were searched from November 2021 to February 2022, for clinical trials: Pubmed, Scopus and Cochrane. From 296 records, 10 studies were included involving in the systematic review. Data from 759 patients who received chemoradiotherapy were analyzed. These studies used different classifications for oral mucositis (WHO, NCI, RTOF/EORTC), pain (VAS) and quality of life (EORTC QLQ-C30, UW-QOL (v4), FACT-HN). PBM therapy protocol used five different lasers (GaAlAs, InGaAlP, He-Ne, diode laser, red and near-IR LED probe) with wavelengths ranging from 632,8nm to 850nm. Pain evaluation in was based on the visual analogue scale (VAS) mainly. Prophylactic PBM was effective as it reduced the incidence of grades 3-4 and reduced the overall mean grade of OM during the chemoradiotherapy course compared to the control group. On the other hand, when PBM was used for treatment purposes, it decreased the mean duration of OM compared to the placebo arm.

Conclusions

PBM reduced the incidence of more severe grade of OM induced by chemoradiotherapy. Also, PBM therapy reduced the mean duration of severe OM, mean pain scores and subsequently improved QoL. Key words:Oral mucositis, photobiomodulation, low-level laser therapy, chemotherapy, radiotherapy.

Evaluation of oral mucositis, candidiasis, and quality of life in patients with head and neck cancer treated with a hypofractionated or conventional radiotherapy protocol: a longitudinal, prospective, observational study

BACKGROUND

Due to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, recently, Radiotherapy (RT) protocols requiring fewer sessions (hypofractionated) have been used to shorten RT treatment and minimize patient exposure to medical centers, and decrease the risk of SARS-CoV-2 infection.

METHODS

This longitudinal, prospective, observational study aimed to compare the quality of life (QoL) and the incidence of oral mucositis and candidiasis in 66 patients with head and neck cancer (HNC) who undergo a hypofractionated RT protocol (GHipo), total of 55 Gy for 4 weeks, or a conventional RT protocol (GConv), total of 66 - 70 Gy for 6 - 7 weeks.

PURPOSE

To assess the incidence and severity of oral mucositis, the incidence of candidiasis, and QoL were evaluated using the World Health Organization scale, clinical evaluation, and the QLC-30 and H&N-35 questionnaires, respectively, at the beginning and the end of RT.

RESULTS

The incidence of candidiasis did not show differences between the two groups. However, at the end of RT, mucositis had a higher incidence (p < 0.01) and severity (p < 0.05) in GHipo. QoL was not markedly different between the two groups. Although mucositis worsened in patients treated with hypofractionated RT, QoL did not worsen for patients on this regimen.

CONCLUSIONS

Our results open perspectives for the potential use of RT protocols for HNC with fewer sessions in conditions that require faster, cheaper, and more practical treatments.

Twenty-year analysis of photobiomodulation clinical studies for oral mucositis: a scoping review

OBJECTIVE

Our objective was to review the first 20 years of photobiomodulation (PBM) clinical studies for oral mucositis (OM) mitigation.

STUDY DESIGN

A scoping review screened controlled clinical studies. The PBM devices, protocols, and clinical outcomes were analyzed.

RESULTS

Seventy-five studies met the inclusion criteria. The first study dated from 1992, and the term "PBM" was first published in 2017. Public services, placebo-controlled randomized trials, and patients with head and neck chemoradiation were predominant among included studies. Prophylactic red intraoral laser protocols were mostly used. Comparing the outcomes of all protocols was unfeasible due to missing treatment parameters and nonhomogeneous measurements.

CONCLUSIONS

The main barrier to optimizing clinical protocols of PBM for OM was the lack of standardization in clinical studies. Although PBM use is now globally present in oncology settings and generally marked by good outcomes reported, additional randomized clinical trials with well-described methods are necessary.

New Insights into the Relationship between Gut Microbiota and Radiotherapy for Cancer

Cancer is the second most common cause of death among humans in the world, and the threat that it presents to human health is becoming more and more serious. The mechanisms of cancer development have not yet been fully elucidated, and new therapies are changing with each passing day. Evidence from the literature has validated the finding that the composition and modification of gut microbiota play an important role in the development of many different types of cancer. The results also demonstrate that there is a bidirectional interaction between the gut microbiota and radiotherapy treatments for cancer. In a nutshell, the modifications of the gut microbiota caused by radiotherapy have an effect on tumor radiosensitivity and, as a result, affect the efficacy of radiotherapy and show a certain radiation toxicity, which leads to numerous side effects. What is of new research significance is that the "gut-organ axis" formed by the gut microbiota may be one of the most interesting potential mechanisms, although the relevant research is still very limited. In this review, we combine new insights into the relationship between the gut microbiota, cancer, and radiotherapy. Based on our current comprehensive understanding of this relationship, we give an overview of the new cancer treatments based on the gut microbiota.

The Effects of Blue Light on Human Fibroblasts and Diabetic Wound Healing

Diabetes is a serious threat to global health and is among the top 10 causes of death. The Diabetic foot ulcer (DFU) is among the most common and severe complications of the disease. Bacterial infections are common; therefore, timely aggressive management, using multidisciplinary management approaches is needed to prevent complications, morbidity, and mortality, particularly in view of the growing cases of antibiotic-resistant bacteria. Photobiomodulation (PBM) involves the application of low-level light at specific wavelengths to induce cellular photochemical and photophysical responses. Red and near-infrared (NIR) wavelengths have been shown to be beneficial, and recent studies indicate that other wavelengths within the visible spectrum could be helpful as well, including blue light (400–500 nm). Reports of the antimicrobial activity and susceptibility of blue light on several strains of the same bacterium show that many bacteria are less likely to develop resistance to blue light treatment, meaning it is a viable alternative to antibiotic therapy. However, not all studies have shown positive results for wound healing and fibroblast proliferation. This paper presents a critical review of the literature concerning the use of PBM, with a focus on blue light, for tissue healing and diabetic ulcer care, identifies the pros and cons of PBM intervention, and recommends the potential role of PBM for diabetic ulcer care.

Comparison of Pulsed and Continuous Wave Diode Laser at 940 nm on the Viability and Migration of Gingival Fibroblasts

Gingival fibroblasts have critical roles in oral wound healing. Photobiomodulation (PBM) has been shown to promote mucosal healing and is now recommended for managing oncotherapy-associated oral mucositis. This study examined the effects of the emission mode of a 940 nm diode laser on the viability and migration of human gingival fibroblasts. Cells were cultured in a routine growth media and treated with PBM (average power 0.1 W/cm² , average fluence 3 J/cm² , every 12h for 6 sessions) in one continuous wave (CW) and two pulsing settings with 20 % and 50 % duty cycles. Cell viability was assessed using MTT, and digital imaging quantified cell migration. After 48 and 72 hours, all treatment groups had significantly higher viability (n = 6, p < 0.05) compared to the control. The highest viability was seen in the pulsed (20% duty cycle) group at the 72-hour time point. PBM improved fibroblast migration in all PBM-treated groups, but differences were not statistically significant (n = 2, p > 0.05). PBM treatments can promote cell viability in both continuous and pulsed modes. Further studies are needed to elucidate the optimal setting for PBM-evoked responses for its rationalized use in promoting specific phases of oral wound healing.

Therapeutic Potential of Photobiomodulation for Chronic Kidney Disease

Chronic kidney disease (CKD) is a growing global public health problem. The implementation of evidence-based clinical practices only defers the development of kidney failure. Death, transplantation, or dialysis are the consequences of kidney failure, resulting in a significant burden on the health system. Hence, innovative therapeutic strategies are urgently needed due to the limitations of current interventions. Photobiomodulation (PBM), a form of non-thermal light therapy, effectively mitigates mitochondrial dysfunction, reactive oxidative stress, inflammation, and gut microbiota dysbiosis, all of which are inherent in CKD. Preliminary studies suggest the benefits of PBM in multiple diseases, including CKD. Hence, this review will provide a concise summary of the underlying action mechanisms of PBM and its potential therapeutic effects on CKD. Based on the findings, PBM may represent a novel, non-invasive and non-pharmacological therapy for CKD, although more studies are necessary before PBM can be widely recommended.

Photobiomodulation: a promising innovative approach for preventing oral mucositis in patients undergoing hematopoietic stem cell transplantation

PURPOSE

This single-center retrospective study aims to assess the feasibility, safety, and tolerability of CareMin650, a new photobiomodulation device, for both preventing oral mucositis (OM) and reducing its severity in the setting of hematopoietic stem cell transplantation (HCT).

METHODS

Patients who underwent autologous HCT for hematological malignancies between November 2020 and October 2021 could be included. Prophylactic photobiomodulation (PBM) was used daily from day 1 of conditioning until the day of neutrophil recovery at a dose of 3 J/cm². Curative PBM was started at a dose of 6 J/cm² when at least one grade 1 OM had occurred. For each OM case, time of onset, National Cancer Institute-Common Terminology Criteria for Adverse Events (NCI-CTCAE) v5.0 grade for OM, analgesic dose, and time to resolution were reported.

RESULTS

Twenty-five consecutive patients were included. The median age was 58 years (range, 39-74) and 14 (56%) were male. Twenty-one patients (84%) received a high-dose melphalan conditioning regimen for multiple myeloma, and 4 (16%) patients received BEAM conditioning for aggressive lymphoma. A total of 178 CareMin650 sessions were performed, with a median of 7 days of application (range, 4-12), with no device-related adverse events (AEs). According to the NCI-CTCAE v5.0 scale, 76% (19 of 25) of patients presented grade 0 or 1 mucositis (no ulcers), five patients (20%) developed small ulcers (grade 2), and only one patient developed grade 4 mucositis. Satisfaction rates were high among patients and users.

CONCLUSION

Photobiomodulation provides excellent safety and tolerance, as well as promising efficacy, both as a preventive and curative strategy, in patients undergoing autologous HCT.

Laser oromaxillofacial photobiomodulation therapy: molecular mechanisms, outcomes and considerations

Tweetable abstract Photobiomodulation therapy is largely characterized as a safe therapeutic model that can modulate the activity of inflammatory and immune biomarkers while facilitating a metabolic response that can regenerate damaged tissue.

Laser Needle Knife's Effects on Rabbits Cervical Spondylopathy of Vertebral Artery, Fibrinogen, and Blood Viscosity

Objective

To determine the effect of laser needle-knife on vertebroarterial morphology, fibrinogen and blood viscosity in a rabbit model of cervical spondylotic arteriopathy (CSA) and the mechanism of action involved.

Methods

A number of 40 healthy common grade rabbits were divided into four groups: normal control, model, acupuncture, and laser needle knife group. The normal control group does not establish a CSA rabbit model, and the other groups all establish a CSA rabbit model, but they are treated in different ways. CSA model rabbits were treated with acupuncture and moxibustion at “fengchi” and “cervical Jiaji” points, rabbits in the laser needle knife group were treated with “Jiaji” points, and the acupuncture points were punctured with the laser needle knife. The location of the acupuncture points is determined according to the acupoint map of the experimental map. The right vertebroarterial morphology before and after the treatment was analyzed by scanning electron microscope, and FIB concentration and blood viscosity were determined using the coagulation method.

Results

After the treatment, the capillary and micropore hyperplasia in the laser needle knife group were more evident than that in the model group. Acupuncture and laser needle knife therapy can reduce whole blood viscosity (1/s, 5/s), and that the distinction between the two treatments is not statistically evident.

Conclusion

Acupuncture and laser needle knife can regulate the coagulation and fibrinolysis system in CSA, stimulate capillary and micropore hyperplasia, reduce blood viscosity, and improve blood circulation, which may be one of the therapeutic mechanisms behind the laser needle knife treatment of CSA.

Regulatory Processes of the Canonical Wnt/β-Catenin Pathway and Photobiomodulation in Diabetic Wound Repair

Skin is a biological system composed of different types of cells within a firmly structured extracellular matrix and is exposed to various external and internal insults that can break its configuration. The restoration of skin's anatomic continuity and function following injury is a multifaceted, dynamic, well-coordinated process that is highly dependent on signalling pathways, including the canonical Wnt/β catenin pathway, all aimed at restoring the skin's protective barrier. Compromised and inappropriate tissue restoration processes are often the source of wound chronicity. Diabetic patients have a high risk of developing major impediments including wound contamination and limb amputation due to chronic, non-healing wounds. Photobiomodulation (PBM) involves the application of low-powered light at specific wavelengths to influence different biological activities that incite and quicken tissue restoration. PBM has been shown to modulate cellular behaviour through a variety of signal transduction pathways, including the Wnt/β catenin pathway; however, the role of Wnt/β catenin in chronic wound healing in response to PBM has not been fully defined. This review largely focuses on the role of key signalling pathways in human skin wound repair, specifically, the canonical Wnt/β-catenin pathway, and the effects of PBM on chronic wound healing.

[Low-level laser therapy in oncology - what's new? Analysis of 2018-2021 publications]

Low-level laser therapy (LLLT) is included in the Federal project «Fight against oncological diseases», which provides for equipping all specialized medical institutions in Russia with the appropriate devices until 2026.

PURPOSE OF THE STUDY

Publications analysis on the use of LLLT in oncology.

MATERIAL AND METHODS

To search for publications, databases and libraries were used: PubMed, Scopus, ResearchGate, Google Scholar, J-STAGE, eLibrary.ru for the period 2018-2021. For analysis, publications were selected that are of interest from the point of view of improving the methodology of LLLT, the prospects for the development of this method in the prevention, treatment and rehabilitation of patients. A total of 223 publications were found, including 39 reviews and meta-analyses, mostly in English (165) and Portuguese (41).

RESULTS AND DISCUSSION

The inclusion of LLLT in the ISOO/MASCC/ASCO recommendations for the treatment of complications such as mucositis, salivary gland hypofunction and xerostomia caused by non-surgical methods of treating cancer patients should be considered as a promising trend. An extremely low level of quality of LLLT techniques was noted, most often the replacement with meaningless «doses», «fluences» instead of the necessary parameters: wavelength, operating mode, power, frequency, exposure, etc. The use of only local illumination instead of systemic methods of LLLT does not allow obtaining the best results of treatment and prevention. Eliminating the shortcomings of treatment protocols with a focus on Russian experience, when laser blood illumination (intravenously or externally) and laser acupuncture are also necessarily carried out with local illumination of the lesion, will bring the effectiveness of LLLT to a qualitatively new, higher level.

New photobiomodulation device for prevention and cure of radiotherapy-induced oral mucositis and dermatitis: results of the prospective Safe PBM study

Purpose

The study aims to assess the feasibility, safety, and tolerability of CareMin650, a new photobiomodulation device, in patients treated by radiotherapy (RT) and to collect preliminary data on efficacy for prevention and treatment of oral mucositis (OM) and radiation dermatitis (RD).

Methods

Safe PBM is a French, multicentric, prospective, non-comparative study which include patients with head and neck cancer (H&NC, cohort A) or breast cancer (BC, cohort B) treated in prophylactic (cohorts A1 and B1) or curative setting (cohort A2 and B2). Prophylactic treatment was administered from D1 to end of RT, at a dose of 3 J/cm². Curative treatment started when a grade 1 to grade 3 lesion had occurred and was pursued until end of RT. Primary endpoint was incidence of device-related adverse events (AEs). OM and RD lesions were graded according to CTCAE V3.

Results

Overall, 72 patients were included (22, 9, 23, and 18 in cohorts A1, A2, B1, and B2, respectively). No device-related AE was reported after 1312 CareMin650 sessions. In cohorts A1 and B1, median time to first OM or RD lesion was 20 days. One BC patient developed G3 RD after completion of RT and discontinuation of CareMin650. Four H&NC patients developed G3 OM. In cohorts A2 and B2, lesions improved or stabilized in 71% of patients. Rates of satisfaction were high among patients and users.

Conclusion

CareMin650 is feasible, safe, and well tolerated for preventive or curative treatment of OM and RD in cancer patients treated with RT. Preliminary efficacy results are promising.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00520-021-06574-2.

Photobiomodulation with Red and Near-Infrared Light Improves Viability and Modulates Expression of Mesenchymal and Apoptotic-Related Markers in Human Gingival Fibroblasts

Photobiomodulation (PBM), also called low-level laser treatment (LLLT), has been considered a promising tool in periodontal treatment due to its anti-inflammatory and wound healing properties. However, photobiomodulation's effectiveness depends on a combination of parameters, such as energy density, the duration and frequency of the irradiation sessions, and wavelength, which has been shown to play a key role in laser-tissue interaction. The objective of the study was to compare the in vitro effects of two different wavelengths-635 nm and 808 nm-on the human primary gingival fibroblasts in terms of viability, oxidative stress, inflammation markers, and specific gene expression during the four treatment sessions at power and energy density widely used in dental practice (100 mW, 4 J/cm²). PBM with both 635 and 808 nm at 4 J/cm² increased the cell number, modulated extracellular oxidative stress and inflammation markers and decreased the susceptibility of human primary gingival fibroblasts to apoptosis through the downregulation of apoptotic-related genes (P53, CASP9, BAX). Moreover, modulation of mesenchymal markers expression (CD90, CD105) can reflect the possible changes in the differentiation status of irradiated fibroblasts. The most pronounced results were observed following the third irradiation session. They should be considered for the possible optimization of existing low-level laser irradiation protocols used in periodontal therapies.