The effect of phototherapy on neutrophils

Photobiomodulation in the treatment of palmar-plantar erythrodysesthesia: a randomised controlled clinical study protocol

INTRODUCTION

Hand-foot syndrome, also known as palmar-plantar erythrodysesthesia (PPE), is a complication caused by chemotherapy. Clinically, it manifests as erythema and oedema on the palms of the hands and feet, dry and scaly skin, accompanied by a sensation of tightness and pain. Extreme cases have blisters and ulcerations that may require hospitalisation and/or pause in cancer treatment. It can also be accompanied by paraesthesia. Considering the characteristics, photobiomodulation (PBM) may reduce the PPE effects. The objective of this protocol will be to evaluate the efficacy of PBM in reducing PPE induced by capecitabine and 5-fluorouracil chemotherapy.

METHODS AND ANALYSIS

This will be a randomised controlled, double-blind, double-centre clinical trial (Centro Asistencial del Sindicato Médico del Uruguay and Instituto Nacional del Cáncer from Uruguay). The sample population (40 individuals) will be divided into two groups: group 1 will receive moisturising cream plus PBM treatment and group 2 moisturising cream plus PBM sham treatment, at the ratio of 1:1. PBM will be performed at 630 nm two times per week in palmoplantar areas of the hands and feet (4 J/cm2), for 4 weeks. The PPE degree and the data referring to the chemotherapy treatment plan will be measured, prior to the start of treatment in the middle and at the end of it. Quality of life questionnaires will be applied at the beginning of the trial and at the end of treatment. The data will be analysed based on the intention-to-treat analysis and α<0.05 will be considered statistically significant.

ETHICS AND DISSEMINATION

The protocol was approved by the Research Ethics Committee of Universidad Católica del Uruguay (220316b), of Centro Asistencial del Sindicato Médico del Uruguay (221989) and of Instituto Nacional del Cáncer (2023-04). The recruitment has already started (March 2023).

PROTOCOL VERSION

V.2, 27 October 2023.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT05337423).

Application of Different Wavelengths of LED Lights in Antimicrobial Photodynamic Therapy for the Treatment of Periodontal Disease

Therapeutic light has been increasingly used in clinical dentistry for surgical ablation, disinfection, bio-stimulation, reduction in inflammation, and promotion of wound healing. Photodynamic therapy (PDT), a type of phototherapy, has been used to selectively destroy tumor cells. Antimicrobial PDT (a-PDT) is used to inactivate causative bacteria in infectious oral diseases, such as periodontitis. Several studies have reported that this minimally invasive technique has favorable therapeutic outcomes with a low probability of adverse effects. PDT is based on the photochemical reaction between light, a photosensitizer, and oxygen, which affects its efficacy. Low-power lasers have been predominantly used in phototherapy for periodontal treatments, while light-emitting diodes (LEDs) have received considerable attention as a novel light source in recent years. LEDs can emit broad wavelengths of light, from infrared to ultraviolet, and the lower directivity of LED light appears to be suitable for plaque control over large and complex surfaces. In addition, LED devices are small, lightweight, and less expensive than lasers. Although limited evidence exists on LED-based a-PDT for periodontitis, a-PDT using red or blue LED light could be effective in attenuating bacteria associated with periodontal diseases. LEDs have the potential to provide a new direction for light therapy in periodontics.

Insight into the Prospects for Tumor Therapy Based on Photodynamic Immunotherapy

Malignancy is one of the common diseases with high mortality worldwide and the most important obstacle to improving the overall life expectancy of the population in the 21st century. Currently, single or combined treatments, including surgery, chemotherapy, and radiotherapy, are still the mainstream regimens for tumor treatment, but they all present significant side effects on normal tissues and organs, such as organ hypofunction, energy metabolism disorders, and various concurrent diseases. Based on this, theranostic measures for the highly selective killing of tumor cells have always been a hot area in cancer-related fields, among which photodynamic therapy (PDT) is expected to be an ideal candidate for practical clinical application due to its precise targeting and excellent safety performance, so-called PDT refers to a therapeutic method mainly composed of photosensitizers (PSs), laser light, and reactive oxygen species (ROS). Photoimmunotherapy (PIT), a combination of PDT and immunotherapy, can induce systemic antitumor immune responses and inhibit continuing growth and distant metastasis of residual tumor cells, demonstrating a promising application prospect. This article reviews the types of immune responses that occur in the host after PDT treatment, including innate and adaptive immunity. To further help PIT-related drugs improve their pharmacokinetic properties and bioavailability, we highlight the potential improvement of photodynamic immunotherapy from three aspects: immunostimulatory agents, tumor-associated antigens (TAAs) as well as different immune cells. Finally, we focus on recent advances in various strategies and shed light on their corresponding mechanisms of immune activation and possible clinical applications such as cancer vaccines. Having discovered the inherent potential of PDT and the mechanisms that PDT triggers host immune responses, a variety of immunotherapeutic strategies have been investigated in parallel with approaches to improve PDT efficiency. However, it remains to be further elucidated under what conditions the immune effect induced by PDT can achieve tumor immunosuppression and to what extent PDT-induced antitumor immunity will lead to complete tumor rejection. Currently, PIT presents several outstanding intractable challenges, such as the aggregation ability of PSs locally in tumors, deep tissue penetration ability of laser light, immune escape, and biological toxicity, and it is hoped that these issues raised will help to point out the direction of preclinical research on PIT and accelerate its transition to clinical practice.

Role of phototherapy, BAX gene expression in hyperbilirubinemia development in full-term neonates

Background

Phototherapy is the main therapeutic interference for neonatal hyperbilirubinemia used to escape an exchange transfusion and to decrease the risk of bilirubin-induced encephalopathy (kernikterus). Phototherapy has an oxidative effect on cell components and cell membranes by enhancing peroxidation of lipid and damage to DNA. Many genes function as apoptosis regulatory genes. Examples of these genes involve the BCL2 gene as an anti-apoptotic oncogene, and the BAX gene which is a promoter of apoptosis.

We aimed to evaluate the effect of phototherapy on expression of BAX and Bcl2 genes in hyperbilirubinemic full-term neonates.

Eighteen full-term neonates with indirect hyperbilirubinemia who received phototherapy for 24 h were enrolled as a study group and nine apparently healthy full-term neonates with a normal serum bilirubin level were included as a control group. Assessment of the anti-apoptotic effect(s) of BCL2 and the pro-apoptotic effect(s) of (Bax) genes was achieved by quantitative assay of their products (BCL2 and BAX proteins) by ELISA assay after phototherapy.

Results

Significant decrease in the bcl2 (p < 0.001) and increase in Bax protein (p < 0.001) serum levels after phototherapy in hyperbilirubinemic full-term neonates.

Conclusion

Hyperbilirubinemia has no apoptotic influence, while phototherapy induces apoptosis in the peripheral blood of hyperbilirubinemic full-term infants.

Good, better, best? The effects of polarization on photobiomodulation therapy

Photobiomodulation therapy (PBMT) is a widely adopted form of phototherapy used to treat many chronic conditions that effect the population at large. The exact physiological mechanisms of PBMT remain unsolved; however, the prevailing theory centres on changes in mitochondrial function. There are many irradiation parameters to consider when investigating PBMT, one of which is the state of polarization. There is some evidence to show that polarization of red and near-infrared light may promote different and/or increased biological activity when compared to otherwise identical non-polarized light. These enhanced cellular effects may also be present when the polarized light is applied linear to the tissue direction. Herein, we synthesize the current experimental and clinical evidence pertaining to polarized photobiomodulation therapy; ultimately, to better inform future research into this area of phototherapy.

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.

The effect of red-to-near-infrared (R/NIR) irradiation on inflammatory processes

Introduction: Near-infrared (NIR) and red-to-near-infrared (R/NIR) radiation are increasingly applied for therapeutic use. R/NIR-employing therapies aim to stimulate healing, prevent tissue necrosis, increase mitochondrial function, and improve blood flow and tissue oxygenation. The wide range of applications of this radiation raises questions concerning the effects of R/NIR on the immune system. Methods: In this review, we discuss the potential effects of exposure to R/NIR light on immune cells in the context of physical parameters of light. Discussion: The effects that R/NIR may induce in immune cells typically involve the production of reactive oxygen species (ROS), nitrogen oxide (NO), or interleukins. Production of ROS after exposure to R/NIR can either be inhibited or to some extent increased, which suggests that detailed conditions of experiments, such as the spectrum of radiation, irradiance, exposure time, determine the outcome of the treatment. However, a wide range of immune cell studies have demonstrated that exposure to R/NIR most often has an anti-inflammatory effect. Finally, photobiomodulation molecular mechanism with particular attention to the role of interfacial water structure changes for cell physiology and regulation of the inflammatory process was described. Conclusions: Optimization of light parameters allows R/NIR to act as an anti-inflammatory agent in a wide range of medical applications.

A novel bioscaffold with naturally-occurring extracellular matrix promotes hepatocyte survival and vessel patency in mouse models of heterologous transplantation

BACKGROUND

Naïve decellularized liver scaffold (nDLS)-based tissue engineering has been impaired by the lack of a suitable extracellular matrix (ECM) to provide "active micro-environmental" support.

AIM

The present study aimed to examine whether a novel, regenerative DLS (rDLS) with an active ECM improves primary hepatocyte survival and prevents thrombosis.

METHODS

rDLS was obtained from a 30-55% partial hepatectomy that was maintained in vivo for 3-5 days and then perfused with detergent in vitro. Compared to nDLS generated from normal livers, rDLS possesses bioactive molecules due to the regenerative period in vivo. Primary mouse hepatocyte survival was evaluated by staining for Ki-67 and Trypan blue exclusion. Thrombosis was assessed by immunohistochemistry and ex vivo diluted whole-blood perfusion. Hemocompatibility was determined by near-infrared laser-Doppler flowmetry and heterotopic transplantation.

RESULTS

After recellularization, rDLS contained more Ki-67-positive primary hepatocytes than nDLS. rDLS had a higher oxygen saturation and blood flow velocity and a lower expression of integrin αIIb and α4 than nDLS. Tumor necrosis factor-α, hepatocyte growth factor, interleukin-10, interleukin-6 and interleukin-1β were highly expressed throughout the rDLS, whereas expression of collagen-I, collagen-IV and thrombopoietin were lower in rDLS than in nDLS. Improved blood vessel patency was observed in rDLS both in vitro and in vivo. The results in mice were confirmed in large animals (pigs).

CONCLUSION

rDLS is an effective DLS with an "active microenvironment" that supports primary hepatocyte survival and promotes blood vessel patency. This is the first study to demonstrate a rDLS with a blood microvessel network that promotes hepatocyte survival and resists thrombosis.

Phototherapy in Scleroderma

Systemic and localized scleroderma are difficult to manage diseases with no accepted gold standard of therapy to date. Phototherapeutic modalities for scleroderma show promise. A PubMed search of information on phototherapy for scleroderma was conducted. The information was classified into effects on pathogenesis and clinical outcomes. Studies on photopheresis were excluded. There were no randomized, double-blind, placebo-controlled studies, and only three controlled studies. The vast majority of identified studies evaluated ultraviolet A1 (UVA1) phototherapy. More rigorous studies are needed to evaluate phototherapy in the treatment of scleroderma. Based on the limited studies available, 20-50 J/cm² of UVA1 therapy 3-4 times a week for 30 treatments is recommended.

Necrotizing enterocolitis following intensive phototherapy in full-term newborns – is there a possible association?

Background: Necrotizing enterocolitis is rare in full-term infants, and is currently not considered a known complication of phototherapy.

Highlights: Three cases of necrotizing enterocolitis in full-term babies possibly associated to intensive phototherapy for treatment of early neonatal hyperbilirubinemia due to isoimmune hemolytic disease of the newborn.

Conclusions: Although rare, the association between occurrences of necrotizing enterocolitis in full-term newborn infants and intensive phototherapy merits caution and clinical awareness to such possible complication. Presumptive explanation is that intensive phototherapy causes marked vasodilataion in the skin that may result in decreased perfusion of the intestine leading to ischemia and necrotizing enterocolitis. This calls for further studies to investigate the effects of phototherapy on the vascular bed in the gut and other vital organs that could have clinical implications.

Phototherapy for chronic rhinosinusitis

OBJECTIVES

Near-infrared laser illumination (NILI), with or without photo-activated (PA) agents, has bactericidal and wound healing promoting effects. NILI may have a potential role managing chronic rhinosinusitis (CRS).

METHODS

A prospective randomized study with 23 symptomatic post-surgical CRS patients with positive cultures was conducted. Two groups (GR1 and GR2) were treated with NILI. Objective nasal endoscopic scoring (NES) was elaborated. GR1 was treated with a 940 nm laser, while GR2 was treated with a topical PA agent, indocyanine-green, followed with 810 nm laser. SNOT20 scores, NES, and cultures were obtained prior to illumination. Saccharin test was performed 1 week following treatment.

RESULTS

Some cultures remained positive through treatment, with Staph. aureus predominating. Both therapy arms demonstrated clinical efficacy. The SNOT20 score change was 0.9, 0.8 for GR1 and GR2, respectively (P < 0.05). Improvement (P < 0.05) was observed based on NES. No significant difference was observed between two treatment groups. All passed the saccharin test. Therapeutic effect was sustained for a minimum of 2 months. Side effects were minimal.

CONCLUSIONS

NILI was objectively and subjectively beneficial in managing CRS, safe, reproducible, sustained and appeared not to interfere with ciliary motility. CRS exacerbation was avoided without using antibiotics or steroids.

Impact of photodynamic therapy on inflammatory cells during human chronic periodontitis

The aim of this study was to evaluate the effects of the photodynamic therapy (PDT) on the inflammatory infiltrate and on the collagen network organization in human advanced chronic periodontitis. Two different drug delivery systems (DDS) were tested (liposomes and nanoemulsions) to determine if the effects of PDT could differ according to the DDS used. Sixteen patients presenting two teeth with chronic advanced periodontitis and important tooth mobility with clinical indication of extraction were included in the group liposomes (group L, n=8) or in the group nanoemulsions (group N, n=8) in order to compare the effects of each DDS. Seven days before extractions one tooth of each patient was treated with PDT using phthalocyanine derivatives as photosensitizers and the contralateral tooth was taken as control. In group L the density of gingival collagen fibers (66±19%) was significantly increased (p<0.02) when compared to controls (35±21%). Concerning the antigen-presenting cells, PDT had differential effects depending on the drug delivery system; the number of macrophages was significantly decreased (p<0.05) in group L while the number of Langerhans cells was significantly decreased in group N (p<0.02). These findings demonstrate that PDT presents an impact on gingival inflammatory phenomenon during chronic periodontitis and leads to a specific decrease of antigen-presenting cells populations according to the drug delivery system used.