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Previous studies have shown that antimicrobial photodynamic inactivation (aPDI) can be strongly potentiated by the addition of the non-toxic inorganic salt, potassium iodide (KI). This approach was shown to apply to many different photosensitizers, including the xanthene dye Rose Bengal (RB) excited by green light (540 nm). Rose Bengal diacetate (RBDA) is a lipophilic RB derivative that is easily taken up by cells and hydrolyzed to produce an active photosensitizer. Because KI is not taken up by microbial cells, it was of interest to see if aPDI mediated by RBDA could also be potentiated by KI. The addition of 100 mM KI strongly potentiated the killing of Gram-positive methicillin-resistant Staphylocccus aureus, Gram-negative Eschericia coli, and fungal yeast Candida albicans when treated with RBDA (up to 15 µM) for 2 hours followed by green light (540 nm, 10 J/cm2). Both RBDA aPDI regimens (400 µM RBDA with or without 400 mM KI followed by 20 J/cm2 green light) accelerated the healing of MRSA-infected excisional wounds in diabetic mice, without damaging the host tissue. [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD) poses a significant public health problem, affecting millions of people across the world. Despite decades of research into therapeutic strategies for AD, effective prevention or treatment for this devastating disorder remains elusive. In this review, we discuss the potential of photobiomodulation (PBM) for preventing and alleviating AD-associated pathologies, with a focus on the biological mechanisms underlying this therapy. Future research directions and guidance for clinical practice for this non-invasive and non-pharmacological therapy are also highlighted. The available evidence indicates that different treatment paradigms, including transcranial and systemic PBM, along with the recently proposed remote PBM, all could be promising for AD. PBM exerts diverse biological effects, such as enhancing mitochondrial function, mitigating the neuroinflammation caused by activated glial cells, increasing cerebral perfusion, improving glymphatic drainage, regulating the gut microbiome, boosting myokine production, and modulating the immune system. We suggest that PBM may serve as a powerful therapeutic intervention for AD. [ABSTRACT FROM AUTHOR]

Far‐infrared radiation (FIR) has been investigated for reduction of pain and improvement of dermal blood flow. The FIRTECH patch is a medical device designed to re‐emit FIR radiated by the body. This phase 1 study was conducted to evaluate the local effects of the FIRTECH patch on local skin perfusion, microcirculation and oxygenation. This prospective, randomized, open‐label, parallel designed study admitted 20 healthy participants to a medical research facility for treatment for 31 h on three anatomical locations. During treatment, imaging assessments consisting of laser speckle contrast imaging, near‐infrared spectroscopy, side‐stream dark‐field microscopy, multispectral imaging and thermography were conducted regularly on patch‐treated skin and contralateral non‐treated skin. The primary endpoint was baseline perfusion increase during treatment on the upper back. Secondary endpoints included change in baseline perfusion, oxygen consumption and temperature of treated versus untreated areas. The primary endpoint was not statistically significantly different between treated and non‐treated areas. The secondary endpoints baseline perfusion on the forearm (least square means [LSMs] difference 2.63 PU, 95% CI: 0.97, 4.28), oxygen consumption (LSMs difference: 0.42 arbitrary units [AUs], 95% CI: 0.04, 0.81) and skin temperature (LSMs difference 0.35°C, 95% CI: 0.16, 0.6) were statistically significantly higher in treated areas. Adverse events observed during the study were mild and transient. The vascular response to the FIRTECH patch was short‐lived suggesting a non‐thermal vasodilatory effect of the patch. The FIRTECH patch was well tolerated, with mild and transient adverse events observed during the study. These results support the therapeutic potential of FIR in future investigations. [ABSTRACT FROM AUTHOR]

Picosecond lasers have a very short pulse duration and a high peak power density. When fractional optical delivery systems are attached to picosecond lasers, they generate an array of concentrated microspots with a high fluence surrounded by areas with a low fluence. This article discusses the histologic characteristics and clinical applications of fractional picosecond laser treatment. Fractional picosecond laser produces laser-induced optical breakdown (LIOB) and laser-induced cavitation (LIC) in the epidermis and dermis respectively, and can encourage skin regeneration and dermal remodeling. It has been shown that fractional picosecond laser has a positive effect on facial photoaging, enlarged facial pores, dyspigmentation, wrinkles, and atrophic scars. Further research is still needed to confirm the benefits of fractional picosecond lasers. [ABSTRACT FROM AUTHOR]

An editorial is presented which discusses the benefits of photobiomodulation therapy (PBMT) for Duchenne muscular dystrophy (DMD), a rare genetic disease characterized by muscle weakness and wasting. PBMT, which involves the use of red/near-infrared light to stimulate mitochondria, and could have multiple positive effects on DMD. The author suggests that further research and clinical trials should be conducted to explore the use of PBMT as a potential treatment for DMD.

New therapeutic strategies are urgently needed to overcome drawbacks in the treatment of some infections, particularly sexually transmitted infections (STI). STIs are easily spread by the transmission of various bacteria, viruses, and parasites with some of the infections being incurable or even lethal, leading to a serious impact on reproductive health worldwide. Phototherapy (PT) is a major therapeutic approach based on the controlled administration of light in the visible, near infrared, or UV spectrum, with or without the application of an external photosensitizer. Despite the fact that PT has not been explored to its full potential in the control of STIs, it has already demonstrated good clinical response rates and lower recurrence rates in genital infections. For instance, increasing evidence has demonstrated that 5-aminolevulinic acid photodynamic therapy (5-ALA-PDT) is effective in the treatment of condyloma acuminatum (CA), by eliminating the causative latent human papillomavirus (HPV) infection, and also in the antiviral treatment of recurrent genital herpes simplex virus (HSV) infections. The clinical application of PDT is a new treatment for oral fungal infection caused by Candida albicans in adult acquired immune deficiency syndrome (AIDS) patients, with human immunodeficiency virus (HIV), and could also be used for genital fungal infections. Another antimicrobial PT strategy, water-filtered infrared A combined with visible light irradiation, has been shown to be effective against genital Chlamydia trachomatis bacterial infection, and an optical nano-genosensor has been designed for the diagnosis of trichomoniasis, a parasitic Trichomonas vaginalis infection. This review aims to summarize the published evidence for the effectiveness of PT in the treatment of STIs, and for the suppression of STI-related pathogens of various types. [ABSTRACT FROM AUTHOR]

Background: Centrofacial erythema associated with telangiectasis is the most common presentation of rosacea, known as erythematotelangiectatic rosacea (ETR). However, successful management of these symptoms remains challenging. Aim: The purpose of this study was to evaluate the efficacy and safety of topical timolol maleate eye drops 0.5% for ETR. Methods: In this randomized, single‐center, single‐blind, placebo‐controlled split‐face study, 16 patients with mild‐to‐moderate ETR who presented at West China Hospital between January 2019 to September 2020 were randomized to receive either topical timolol maleate eye drops 0.5% to one side of their face daily for 28 days and normal saline to the other side of the face. Patients were assessed with both the Clinician Erythema Assessment (CEA) and Patient Self‐Assessment (PSA) at the 28‐day follow‐up appointment. Subjective assessment was performed by asking participants to grade their sensation of warmth and burning. Results: The sides treated with timolol demonstrated a significant improvement in both the CEA and PSA at the 28‐day assessment. Patients reported a significant difference in warmth and burning sensations. The only adverse reaction was worsened redness on both sides of the face at Day 1 in one patient. Conclusions: In this small study, the application of topical timolol maleate was safe and effective for the treatment of ETR. [ABSTRACT FROM AUTHOR]

An editorial is presented on discovery of biophotons attributed to Alexander Gurwitsch working in the Soviet Union in the 1920s. Topics include biophotons arising from excited state chemical intermediates or reaction products generated within cells; and attempts being made to demonstrate quantum coherence in biophoton emission.

The author reflects on the potential causes and treatments of Gulf War Illness (GWI) that affects mainly veterans in the U.S. and United Kingdom. Topics include the symptoms of GWI like headaches, cognitive impairment, and gastrointestinal disturbance, studies on the possible GWI causes like exposure to acetylcholinesterase inhibitor neurotoxins, and potential treatments like mindfulness-based stress reduction and cognitive behavioral therapy.

The article focuses on Autism that is a neurodevelopmental disorder that is often diagnosed in children within the first 3 years of life and it affects four to five times more boys than girls. Topics include examines the causes of ASD are multifactorial as there is a genetic basis as siblings of affected children are several times more likely to be autistic than the general population.

An editorial is presented on photobiomodulation therapy (PBMT) not becoming a mainstream medical therapy. Topics include hundreds of successful clinical studies and widespread use as an alternative and complementary medicine treatment; and Mitochondria containing a variety of different cytochromes either as part of functional proteins or as electron transport shuttles (cytochrome c).

• Novel coronavirus disease (COVID-19) is a global issue nowadays. • COVID-19 is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). • The current knowledge about the treatment protocol is still limited. • Preventing the virus can be the best way of controlling the pandemic. The novel coronavirus disease (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remains a global challenge. Despite intense research efforts worldwide, an effective vaccine and viable treatment options have eluded investigators. Therefore, infection prevention, early viral detection and identification of successful treatment protocols provide the best approach in controlling disease spread. In this review, current therapeutic options, preventive methods and transmission routes of COVID-19 are discussed. [ABSTRACT FROM AUTHOR]

One of the challenges in translating new therapeutic approaches to the patient bedside lies in bridging the gap between scientists who are conducting basic laboratory research and medical practitioners who are not exposed to highly specialized journals. This review covers the literature on photobiomodulation therapy as a novel approach to prevent and treat Alzheimer's disease, aiming to bridge that gap by gathering together the terms and technical specifications into a single concise suggestion for a treatment protocol. In light of the predicted doubling in the number of people affected by dementia and Alzheimer's disease within the next 30 years, a treatment option which has already shown promising results in cell culture studies and animal models, and whose safety has already been proven in humans, must not be left in the dark. This review covers the mechanistic action of photobiomodulation therapy against Alzheimer's disease at a cellular level. Safe and effective doses have been found in animal models, and the first human case studies have provided reasons to undertake large-scale clinical trials. A brief discussion of the minimally effective and maximum tolerated dose concludes this review, and provides the basis for a successful translation from bench to bedside. [ABSTRACT FROM AUTHOR]

Thomas J Dougherty from Roswell Park Cancer Center played a major role in the progress of photodynamic therapy (PDT) from a laboratory science into a real‐world clinical therapy to treat patients with cancer. Nevertheless over the succeeding 45 years, it is fair to say that the overall progress of clinical PDT for cancer has been somewhat disappointing. The goal of this perspective article is to summarize some of the clinical trials run by various companies using photosensitizers with different structures that have been conducted for different types of cancer. While some have been successful, others have failed, and several are now ongoing. I will attempt to touch on some factors, which have influenced this checkered history and look forward to the future of clinical PDT for cancer. [ABSTRACT FROM AUTHOR]

The promise of engineering specific cell types from stem cells and rebuilding damaged or diseased tissues has fascinated stem cell researchers and clinicians over last few decades. Mesenchymal Stem Cells (MSCs) have the potential to differentiate into non-mesodermal cells, particularly neural-lineage, consisting of neurons and glia. These multipotent adult stem cells can be used for implementing clinical trials in neural repair. Ongoing research identifies several molecular mechanisms involved in the speciation of neuroglia, which are tightly regulated and interconnected by various components of cell signalling machinery. Growing MSCs with multiple inducers in culture media will initiate changes on intricately interlinked cell signalling pathways and processes. Net result of these signal flow on cellular architecture is also dependent on the type of ligands and stem cells investigated in vitro. However, our understanding about this dynamic signalling machinery is limited and confounding, especially with spheroid structures, neurospheres and organoids. Therefore, the results for differentiating neurons and glia in vitro have been inconclusive, so far. Added to this complication, we have no convincing evidence about the electrical conductivity and functionality status generated in differentiating neurons and glia. This review has taken a step forward to tailor the information on differentiating neuroglia with the common methodologies, in practice. [ABSTRACT FROM AUTHOR]

AbstractProteases, enzymes that hydrolyze peptide bonds, have various applications in medicine, clinical applications, and pharmaceutical development. They are used in cancer treatment, wound debridement, contact lens cleaning, prion degradation, biofilm removal, and fibrinolytic agents. Proteases are also crucial in cardiovascular disease treatment, emphasizing the need for safe, affordable, and effective fibrinolytic drugs. Proteolytic enzymes and protease biosensors are increasingly used in diagnostic and therapeutic applications. Advanced technologies, such as nanomaterials-based sensors, are being developed to enhance the sensitivity, specificity, and versatility of protease biosensors. These biosensors are becoming effective tools for disease detection due to their precision and rapidity. They can detect extracellular and intracellular proteases, as well as fluorescence-based methods for real-time and label-free detection of virus-related proteases. The active utilization of proteolytic enzymatic biosensors is expected to expand significantly in biomedical research, in-vitro model systems, and drug development. We focused on journal articles and books published in English between 1982 and 2024 for this study. [ABSTRACT FROM AUTHOR]

Photobiomodulation (PBM) therapy refers to the non-thermal use of visible to near-infrared light (400 to 1100&nm) to stimulate many biological processes [[1]]. Given this, there are numerous well-known medical applications where PBM therapy has a significant role to play, such as wound healing, muscle and tendon repair, autoimmune diseases, arthropathies, and esthetic applications [[2]]. 10 Yang L, Wu C, Tucker L, Dong Y, Li Y, Xu P, Zhang Q (2021) Photobiomodulation therapy attenuates anxious-depressive-like behavior in the TgF344 rat model. [Extracted from the article]

The article provides information on photobiomodulation therapy (PBMT) for skin pigmentation disorders. Topics discussed include the main evolutionary purpose of skin pigmentation, treatments that have been tested for vitiligo, and a study by C. T. Oh and colleagues on how PBMT might reduce melanin production in the skin.

An editorial is presented on the potential benefits of incorporating infrared radiation (IR) into indoor lighting systems. It highlights the shift from traditional incandescent light bulbs to fluorescent tubes and LED (Light Emitting Diode) lighting for energy efficiency purposes. It further explores whether the absence of IR exposure in modern lifestyles could contribute to various health conditions and diseases.

The article offers information on mitochondrial transplantation focuses on isolation of mitochondria from cells, which had developed resistance to cytotoxic antibiotics, and when these mitochondria were incubated with antibiotic-sensitive cells, the resistance was transferred, suggesting that the mitochondria had been taken up by the recipient cells by a process of endocytosis.

Background: Musculoskeletal disorders caused by osteoarthritis (MSDs/OA) are a growing problem in the modern industrialized society in Canada. Overall aging of the general population and a progressive lack of exercise contribute to this alarming increase. Moreover, a range of chronic conditions including cardiovascular and mental diseases show significantly higher comorbidity with MSDs/OA. Conventional medical treatment for MSDs/OA includes nonsteroidal anti-inflammatory drugs and opiate pain killers. These drugs have major drawbacks such as a relative lack of efficacy, potential for addiction, and even death (Vioxx scandal). Photobiomodulation (PBM) was discovered over 50 years ago but has still not attained widespread acceptance by the medical community. This is partly due to uncertainty about the precise molecular mechanisms of action and a bewildering array of different wavelengths and dosimetric parameters employed in reported studies. Objective: The goal of this review was to survey literature reports of PBM, also known as low-level laser therapy used for treatment of MSDs/OA, concentrating on the growth over time, different wavelengths employed, and application to different joints. Methods: We searched the PubMed database for publication of study on PBM to treat the most common joints. Results: We show that the field of PBM to treat MSDs/OA is expanding exponentially over the past 20 years. A trend has emerged over time for more power to achieve better effective treatments, and the understanding of the physiological effect of safe parameters has improved. There is, however, no consensus on the best set of parameters to treat a specific patient indication. Conclusions: Finally, we highlight gaps in our knowledge and the barriers to further clinical trials. We suggest that the growing body of evidence indicating efficacy, and the almost total lack of side effects, should encourage continued clinical research to support clinical applications where better rehabilitation treatments are much needed. [ABSTRACT FROM AUTHOR]

The relentless rise of antibiotic resistance is considered one of the most serious problems facing mankind. This mini‐review will cover three cutting‐edge approaches that use light‐based techniques to kill antibiotic‐resistant microbial species, and treat localized infections. First, we will discuss antimicrobial photodynamic inactivation using rationally designed photosensitizes combined with visible light, with the added possibility of strong potentiation by inorganic salts such as potassium iodide. Second, the use of blue and violet light alone that activates endogenous photoactive porphyrins within the microbial cells. Third, it is used for "safe UVC" at wavelengths between 200 nm and 230 nm that can kill microbial cells without damaging host mammalian cells. We have gained evidence that all these approaches can kill multidrug resistant bacteria in vitro, and they do not induce themselves any resistance, and moreover can treat animal models of localized infections caused by resistant species that can be monitored by noninvasive bioluminescence imaging. Light‐based antimicrobial approaches are becoming a growing translational part of anti‐infective treatments in the current age of resistance. [ABSTRACT FROM AUTHOR]

Photobiomodulation (PBM), also known as low‐level laser (light) therapy, was discovered over 50 years ago, but only recently has it been making progress toward wide acceptance. PBM originally used red and near‐infrared (NIR) lasers, but now other wavelengths and non‐coherent light‐emitting diodes (LEDs) are being explored. The almost complete lack of side effects makes the conduction of controlled clinical trials relatively easy. Laboratory research has mainly concentrated on mammalian cells (normal or cancer) in culture, and small rodents (mice and rats) as models of different diseases. A sizeable body of work was carried out in the 1970s and 1980s in Russia looking at various bacterial and fungal cells. The present review covers some of these studies and a recent number of papers that have applied PBM to so‐called "model organisms." These models include flies (Drosophila), worms (Caenorhabditis elegans), fish (zebrafish) and caterpillars (Galleria). Much knowledge about the genomics and proteomics, and many reagents for these organisms already exist. They are inexpensive to work with and have lower regulatory barriers compared to vertebrate animals. Other researchers have studied different models (snails, sea urchins, Paramecium, toads, frogs and chickens). Plants may respond to NIR light differently from visible light (photosynthesis and photomorphogenesis) but PBM in plants has not been much studied. Veterinarians routinely use PBM to treat non‐mammalian patients. The conclusion is that red or NIR light does indeed have significant biologic effects conserved over many different kingdoms, and perhaps it is true that "all life‐forms respond to light." Photobiomodulation (red or near‐infrared light) has been shown to have beneficial effects on many different life‐forms. Although many pre‐clinical studies have been carried out in mice or rats, and clinical studies in humans, it turns out that all life‐forms from bacteria and fungi, to paramecia, worms, insects, fish, amphibians, reptiles and birds respond. Even plants respond to NIR light differently to photosynthesis with visible light. [ABSTRACT FROM AUTHOR]

The article offers information on the history, causes, and treatment options for epilepsy, a chronic seizure disorder affecting millions of people worldwide. Topics include causes of seizures which are due to abnormal neuronal firing in the brain, which can be attributed to brain damage, genetic causes, or reflex epilepsy triggered by various stimuli; how drug treatments have been developed; and the exploration of alternative therapies such as the ketogenic diet and photobiomodulation therapy.

An editorial is presented which discusses risk of chemotherapy drugs causing severe tissue damage and injury if they are accidentally introduced into tissue during infusion or injection. Anthracyclines are the worst offenders, but a new treatment called Totect has been approved for the prevention of anthracycline extravasation injury by chelating free iron ions, inhibiting the redox cycling reaction, and reducing tissue necrosis.

The author reflects on the role of polarized light in photobiomodulation (PBM), which is used to treat various medical diseases and disorders. Also cited are a comparison of the use of light-emitting diodes (LED) and fluorescent light energy (FLE) in PBM, and the effectiveness of the FLE method for treating conditions like rosacea, burns, solar lentigenes, and wound healing.

One class of carbon nanomaterials is the closed cages known as fullerenes. The first member to be discovered in 1985 was C60, called “buckminsterfullerene” as its cage structure resembled a geodesic dome. Due to their extended π-conjugation they absorb visible light, possess a high triplet yield and can generate reactive oxygen species upon illumination, suggesting a possible role of fullerenes in photodynamic therapy (PDT). Pristine C60 is highly hydrophobic and prone to aggregation, necessitating functionalization to provide aqueous solubility and biocompatibility. The most common functional groups attached are anionic (carboxylic or sulfonic acids) or cationic (various quaternary ammonium groups). Depending on the functionalization, these fullerenes can be designed to be taken up into cancer cells, or to bind to microbial cells (Gram-positive, Gram-negative bacteria, fungi). Fullerenes can be excited with a wide range of wavelengths, UVA, blue, green or white light. We have reported a series of functionalized fullerenes (C60, C70, C82) with attached polycationic chains and additional light-harvesting antennae that can be used in vitro and in animal models of localized infections. Advantages of fullerenes as photosensitizers are: (a) versatile functionalization; (b) light-harvesting antennae; (c) ability to undergo Type 1, 2, and 3 photochemistry; (d) electron transfer can lead to oxygen-independent photokilling; (e) antimicrobial activity can be potentiated by inorganic salts; (f) can self-assemble into supramolecular fullerosomes; (g) components of theranostic nanoparticles; (h) high resistance to photobleaching. Disadvantages include: (a) highly hydrophobic and prone to aggregation; (b) overall short wavelength absorption; (c) relatively high molecular weight; (d) paradoxically can be anti-oxidants; (e) lack of fluorescence emission for imaging. [ABSTRACT FROM AUTHOR]

Abstract Irradiation with red light or near-infrared (NIR) lasers can bio-modulate cellular processes or revitalize injured tissues and therefore, widely been used for therapeutic interventions. Mechanistically, this cellular or biological process, referred as Photobiomodulation (PBM), is achieved by the generation of oxide free radicals in cells and tissues. This explorative study using red light (636 nm) and Near Infra-Red (NIR, 825 nm) laser at various irradiation exposures reckons the level of oxidative stress induced by these free radicals in human primary fibroblasts. Freshly isolated dermal fibroblasts were irradiated with red light and NIR at power densities of 74 and 104 mV/cm2, respectively and, at varying fluences ranging from 5 to 25 J/cm2. Cellular oxidative stress, measured by Reactive Oxygen Species (ROS) upon quantifying fluorescently labelled oxide free radicals in cells, detected considerable variations between the irradiation exposures of red light and NIR laser. The NIR laser demonstrated high levels of ROS at all fluences, except 10 J/cm2 indicating its ability in generating of two types of oxide radicals in dermal fibroblasts, often illustrated as biphasic response. Further, the responses of these cells to variable fluences of red light and NIR laser were measured to evaluate the immediate effect of PBM on cellular activity. The production of cellular energy coincides with the amount of oxidative stress, which was two-fold higher in cells irradiated with the NIR laser, as compared with the red light. This outcome indicates that the ROS production within biological systems are more dependent on the wavelength of the laser rather than its fluences. Further studies are required to avoid 'overdosing of PBM' and to analyse ROS qualitatively for making the best use of the red light and NIR laser in clinics. Highlights • Therapeutic benefits of red light and near-infrared laser is affected by the generation of Reactive Oxygen Species (ROS). • Generation of ROS in cells correlates with the wavelength of red light and near-infrared laser and, not its fluence. • While red light relieves oxidative stress, near-infrared laser increases ROS and cellular bioenergy in primary fibroblasts. • Cellular mechanism of near-infrared laser signifies biphasic response , often manifested as beneficial and detrimental ROS. • Use of positive and negative controls for the analysis of oxidative stress in primary cells warrants great caution. [ABSTRACT FROM AUTHOR]

Photobiomodulation (PBM) is a treatment method based on research findings showing that irradiation with certain wavelengths of red or near-infrared light has been shown to produce a range of physiological effects in cells, tissues, animals and humans. Scientific research into PBM was initially started in the late 1960s by utilizing the newly invented (1960) lasers, and the therapy rapidly became known as “low-level laser therapy”. It was mainly used for wound healing and reduction of pain and inflammation. Despite other light sources being available during the first 40 years of PBM research, lasers remained by far the most commonly employed device, and in fact, some authors insisted that lasers were essential to the therapeutic benefit. Collimated, coherent, highly monochromatic beams with the possibility of high power densities were considered preferable. However in recent years, non-coherent light sources such as light-emitting diodes (LEDs) and broad-band lamps have become common. Advantages of LEDs include no laser safety considerations, ease of home use, ability to irradiate a large area of tissue at once, possibility of wearable devices, and much lower cost per mW. LED photobiomodulation is here to stay. [ABSTRACT FROM AUTHOR]

Photodynamic therapy (PDT) involves the combination of non-toxic dyes called photosensitizers (PS) and harmless visible light that interact with ambient oxygen to give reactive oxygen species (ROS) that can damage biomolecules and kill cells. PDT has mostly been developed as a cancer therapy but can also be used as an antimicrobial approach against localized infections. However even the longest wavelength used for exciting PS (in the 700 nm region) has relatively poor tissue penetration, and many PS are much better excited by blue and green light. Therefore upconversion nanoparticles (UCNPs) have been investigated in order to allow deeper-penetrating near-infrared light (980 nm or 810 nm) to be used for PDT. NaYF4 nanoparticles doped with Yb3+ and Er3+ or with Tm3+ and Er3+ have been attached to PS either by covalent conjugation, or by absorption to the coating or shell (used to render the UCNPs biocompatible). Forster resonance energy transfer to the PS then allows NIR light energy to be transduced into ROS leading to cell killing and tumor regression. Some studies have experimentally demonstrated the deep tissue advantage of UCNP-PDT. Recent advances have included dye-sensitized UCNPs and UCNPs coupled to PS, and other potentially synergistic drug molecules or techniques. A variety of bioimaging modalities have also been combined with upconversion PDT. Further studies are necessary to optimize the drug-delivery abilities of the UCNPs, improve the quantum yields, allow intravenous injection and tumor targeting, and ensure lack of toxicity at the required doses before potential clinical applications. [ABSTRACT FROM AUTHOR]

Background: Neurological diseases and disorders pose a challenge for treatment and rehabilitation due to the limited capacity of the nervous system to repair itself. Adipose stem cells (ASCs) are more pliable than any adult stem cells and are capable of differentiating into non-mesodermal tissues, including neurons. Transdifferentiating ASCs to specific neuronal lineage cells enables us to deliver the right type of cells required for a replacement therapy into the nervous system. Methods: Several methodologies are being explored and tested to differentiate ASCs to functional neurons and glia with cellular factors and chemical compounds. However, none of these processes and prototypes has been wholly successful in changing the cellular structure and functional status of ASCs to become identical to neuroglial cells. In addition, successful integration and functional competence of these cells for use in clinical applications remain problematic. Photobiomodulation or low-level laser irradiation has been successfully applied to not only improve ASC viability and proliferation but has also shown promise as a possible enhancer of ASC differentiation. Conclusions: Studies have shown that photobiomodulation improves the use of stem cell transplantation for neurological applications. This review investigates current neuro-differentiation inducers and suitable methodologies, including photobiomodulation, utilizing ASCs for induction of differentiation into neuronal lineages. [ABSTRACT FROM AUTHOR]

Background: Photobiomodulation (PBM) therapy is a rapidly growing approach to stimulate healing, reduce pain, increase athletic performance, and improve general wellness. Objective: Applying PBM therapy over the site of a tumor has been considered to be a contraindication. However, since another growing use of PBM therapy is to mitigate the side effects of cancer therapy, this short review seeks to critically examine the evidence of whether PBM therapy is beneficial or harmful in cancer patients. Materials and methods: PubMed and Google Scholar were searched. Results: Although there are a few articles suggesting that PBM therapy can be detrimental in animal models of tumors, there are also many articles that suggest the opposite and that light can directly damage the tumor, can potentiate other cancer therapies, and can stimulate the host immune system. Moreover, there are two clinical trials showing increased survival in cancer patients who received PBM therapy. Conclusions: PBM therapy may have benefits in cancer patients and should be further investigated. [ABSTRACT FROM AUTHOR]

Photobiomodulation (PBM) involves the use of red or nearinfrared light at low power densities to produce a beneficial effect on cells or tissues. PBM therapy is used to reduce pain, inflammation, edema, and to regenerate damaged tissues such as wounds, bones, and tendons. The primary site of light absorption in mammalian cells has been identified as the mitochondria and, more specifically, cytochrome c oxidase (CCO). It is hypothesized that inhibitory nitric oxide can be dissociated from CCO, thus restoring electron transport and increasing mitochondrial membrane potential. Another mechanism involves activation of light or heat-gated ion channels. This review will cover the redox signaling that occurs in PBM and examine the difference between healthy and stressed cells, where PBM can have apparently opposite effects. PBM has a marked effect on stem cells, and this is proposed to operate via mitochondrial redox signaling. PBM can act as a preconditioning regimen and can interact with exercise on muscles. [ABSTRACT FROM AUTHOR]

The article presents the discussion on approach for improving overall health especially cardiovascular health and extending the lifespan. Topics include mechanism of action of saunas being based on the concept of hormesis; and proposed to be nonradiative energy transmission between adjacent water molecules deep into the tissue.

Nanofibers made by electrospinning have been used as bridging materials in animal models to regenerate nerves after spinal cord injury (SCI). In this meta-analysis study, we investigated the effect of these nanofibers on the motor function of animals after SCI. An extensive search in databases was performed. After primary and secondary screening, data included functional behavior, expression of glial fibrillary acidic protein, neurofilament-200 (NF-200), and β-tubulin III were taken from the articles. The quality control of the articles, statistical analysis, and subgroup analysis were performed. The results from 14 articles and 16 separate experiments showed that electrospun nanofibers used alone could improve motor behavior and reduce glial injury after SCI. [ABSTRACT FROM AUTHOR]

Infrared (IR) radiation is electromagnetic radiation with wavelengths between 760 nm and 100,000 nm. Low-level light therapy (LLLT) or photobiomodulation (PBM) therapy generally employs light at red and near-infrared wavelengths (600–100 nm) to modulate biological activity. Many factors, conditions, and parameters influence the therapeutic effects of IR, including fluence, irradiance, treatment timing and repetition, pulsing, and wavelength. Increasing evidence suggests that IR can carry out photostimulation and photobiomodulation effects particularly benefiting neural stimulation, wound healing, and cancer treatment. Nerve cells respond particularly well to IR, which has been proposed for a range of neurostimulation and neuromodulation applications, and recent progress in neural stimulation and regeneration are discussed in this review. The applications of IR therapy have moved on rapidly in recent years. For example, IR therapy has been developed that does not actually require an external power source, such as IR-emitting materials, and garments that can be powered by body heat alone. Another area of interest is the possible involvement of solar IR radiation in photoaging or photorejuvenation as opposites sides of the coin, and whether sunscreens should protect against solar IR? A better understanding of new developments and biological implications of IR could help us to improve therapeutic effectiveness or develop new methods of PBM using IR wavelengths. [ABSTRACT FROM AUTHOR]

Lung cancer is considered one of the major health problems worldwide and the burden is even heavier in Africa. Nanomedicine is considered one of the most promising medical research applications nowadays. This is due to the unique physical and chemical properties of materials at the nanoscale. Silver nanoparticles have been extensively studied recently in many biomedical applications especially in cancer treatment, since they possess multifunctional effects that make these nanostructures ideal candidates for biomedical applications. AgNPs have been proved to have anti‐tumour activity and the mode of cell death was shown to be apoptotic. The goal of the current work was to investigate the degree of DNA damage that may result from the usage of AgNPs as a photosensitiser in photo‐inactivation and to evaluate the generation of reactive oxygen species (ROS) produced in the treatment. The results showed the occurrence of DNA damage in lung cancer cells (A549) through the generation of ROS shown by mitochondrial membrane potential changes. [ABSTRACT FROM AUTHOR]

Background: Low-level laser therapy (LLLT) or photobiomodulation (PBM) is a possible treatment for brain injury, including traumatic brain injury (TBI). Methods: We review the fundamental mechanisms at the cellular and molecular level and the effects on the brain are discussed. There are several contributing processes that have been proposed to lead to the beneficial effects of PBM in treating TBI such as stimulation of neurogenesis, a decrease in inflammation, and neuroprotection. Both animal and clinical trials for ischemic stroke are outlined. A number of articles have shown how transcranial LLLT (tLLLT) is effective at increasing memory, learning, and the overall neurological performance in rodent models with TBI. Results: Our laboratory has conducted three different studies on the effects of tLLLT on mice with TBI. The first studied pulsed against continuous laser irradiation, finding that 10 Hz pulsed was the best. The second compared four different wavelengths, discovering only 660 and 810 nm to have any effectiveness, whereas 732 and 980 nm did not. The third looked at varying regimens of daily laser treatments (1, 3, and 14 days) and found that 14 laser applications was excessive. We also review several studies of the effects of tLLLT on neuroprogenitor cells, brain-derived neurotrophic factor and synaptogenesis, immediate early response knockout mice, and tLLLT in combination therapy with metabolic inhibitors. Conclusions: Finally, some clinical studies in TBI patients are covered. [ABSTRACT FROM AUTHOR]

An interview with Michael R. Hamblin, Principal Investigator at the Wellman Center for Photomedicine at Massachusetts General Hospital, is presented. He commented on topics including start of Wellman Laboratories for Photomedicine with Professor Tayyaba Hasan; focus of his laboratory to use light to treat a wide variety of human diseases; and his partnership with Dr. Christopher Contag from Stanford University for research projects.

Photodynamic therapy (PDT) uses photosensitizers (non-toxic dyes) that are activated by absorption of visible light to form reactive oxygen species (including singlet oxygen) that can oxidize biomolecules and destroy cells. Antimicrobial photodynamic inactivation (aPDI) can treat localized infections. aPDI neither causes any resistance to develop in microbes, nor is affected by existing drug resistance status. We discuss some recent developments in aPDI. New photosensitizers including polycationic conjugates, stable synthetic bacteriochlorins and functionalized fullerenes are described. The microbial killing by aPDI can be synergistically potentiated (several logs) by harmless inorganic salts via photochemistry. Genetically engineered bioluminescent microbial cells allow PDT to treat infections in animal models. Photoantimicrobials have a promising future in the face of the unrelenting increase in antibiotic resistance. [ABSTRACT FROM AUTHOR]

Photodynamic therapy (PDT) was discoveredmore than 100 years ago, and has since become a well-studied therapy for cancer and various non-malignant diseases including infections. PDT uses photosensitizers (PSs, non-toxic dyes) that are activated by absorption of visible light to initially form the excited singlet state, followed by transition to the long-lived excited triplet state. This triplet state can undergo photochemical reactions in the presence of oxygen to form reactive oxygen species (including singlet oxygen) that can destroy cancer cells, pathogenic microbes and unwanted tissue. The dual-specificity of PDT relies on accumulation of the PS in diseased tissue and also on localized light delivery. Tetrapyrrole structures such as porphyrins, chlorins, bacteriochlorins and phthalocyanines with appropriate functionalization have been widely investigated in PDT, and several compounds have received clinical approval. Other molecular structures including the synthetic dyes classes as phenothiazinium, squaraine and BODIPY (boron-dipyrromethene), transition metal complexes, and natural products such as hypericin, riboflavin and curcumin have been investigated. Targeted PDT uses PSs conjugated to antibodies, peptides, proteins and other ligands with specific cellular receptors. Nanotechnology has made a significant contribution to PDT, giving rise to approaches such as nanoparticle delivery, fullerene-based PSs, titania photocatalysis, and the use of upconverting nanoparticles to increase light penetration into tissue. Future directions include photochemical internalization, genetically encoded protein PSs, theranostics, two-photon absorption PDT, and sonodynamic therapy using ultrasound. [ABSTRACT FROM AUTHOR]

The author reflects on treating traumatic brain injury (TBI) using Transcranial, Red/Near-Infrared (NIR) LED Photobiomodulation. Topics discussed include examining brain network using Magnetic resonance imaging (MRI) scanning, deactivation of the brain network, default mode network (DMN) for normal cognitive functioning and need for treatments that directly target injured brain cells to improve the functioning of underlying brain systems.

Macrophages are one of the principal host cell populations in solid tumors. They are capable, due to their plasticity, of acquiring phenotypes that either combat (M1 type) or promote (M2 type) neoplastic growth. These cells, known as tumor-associated macrophages (TAMs), play complex but pivotal roles in the outcome of photodynamic therapy (PDT) of malignant lesions. Among the various parenchymal and stromal cell populations found in tumors, TAMs have been shown to have the greatest capacity for the uptake of systemically administered photosensitizers. Both the tumor-localizing property of photosensitizers and their tumor-localized fluorescence could be partly attributed to the activity of TAMs. Since resident TAMs with accumulated high photosensitizer content will sustain high degrees of PDT damage, this population (predominantly M2 in most tumors) is selectively destroyed, and during the ensuing inflammatory reaction is replaced with newly invading macrophages of M1 phenotype. These macrophages are sentinels responding to DAMP signals from PDT-treated tumor cells and in turn are mobilized to generate a variety of inflammatory/immune mediators and opsonins. They have a critical role in contributing to the therapeutic effect of PDT by mediating disposal of killed cancer cells and by processing/presenting tumor antigens to T lymphocytes. However, TAMs accumulating in the later post-PDT phase can acquire the M2 (healing) phenotype, and could have a role in tumor recurrence by releasing factors that promote angiogenesis and the survival/proliferation of remaining cancer cells. Various therapeutic strategies modulating TAM activity in the PDT response have potential for clinical use for improving PDT-mediated tumor control. [ABSTRACT FROM AUTHOR]

Adipose Stem Cells (ASCs) are capable of neuronal differentiation, which makes them an ideal choice for therapies in nerve injuries. Principally, the differentiation of autologous ASCs to neurons offers solutions for the replacement therapies of nervous system with patient's own genetic background. On the contrary, the use of genetically modified (immortalized) ASCs has the benefit of accessibility by surpassing ethical concerns and ease for propagation as a continuous cell culture. Photobiomodulation (PBM) is a therapeutic modality with laser or light, which is widely been used for modulating stem cell bioprocesses viz. proliferation and differentiation. A comparative analysis was performed to evaluate the neuronal differentiation potential of primary ASCs isolated from a healthy human subject with commercially obtained immortalized ASCs with PBM. The outcome of this analysis will help us to know either primary or immortalized ASCs are most suitable for biomedical applications. Both primary and immortalized ASCs were characterized using their surface protein markers CD44/90/133/166 and induced to differentiate into neuronal cells using Fibroblast Growth Factor, basic (bFGF) and forskolin following PBM using Near Infra-Red (NIR) lasers. Based on the expression of nestin, an early neuronal marker an exposure to 5, 10 and 15 J/cm2 of NIR and growth inducers for 14 days the primary ASCs demonstrated a higher neuronal differentiation potential compared to the immortalized ASCs. However, newly differentiated cells from either of these ASCs did not reveal βIII-tubulin, an intermediate neuronal marker even by 21 days of differentiation. This study gives an indication that immortalized ASCs have a phenotype and differentiation potential slightly less but comparable to the freshly isolated ASCs. We suggest that PBM along with growth inducers offer a better solution of differentiating ASCs to neurons. [Display omitted] • Photobiomodulation can differentiate primary human adipose-derived stem cells (ASCs) to neuronal cells. • Neuronal differentiation of primary human ASCs is achievable by near infrared laser of 825 nm. • A significant increase in neuronal differentiation is achievable using 5, 10 and 15 J/cm2 at 825 nm. • Photobiomodulation-induced differentiation potential of primary human ASCs is higher than in immortalized human ASCs. [ABSTRACT FROM AUTHOR]

This special issue of Current Opinion in Pharmacology is concerned with new developments in antimicrobial drugs and covers innovative strategies for dealing with microbial infection in the age of multi-antibiotic resistance. Despite widespread fears that many infectious diseases may become untreatable, disruptive innovations are in the process of being discovered and developed that may go some way to leading the fight-back against the rising threat. Natural products, quorum sensing inhibitors, biofilm disruptors, gallium-based drugs, cyclodextrin inhibitors of pore-forming toxins, anti-fungals that deal with biofilms, and light based antimicrobial strategies are specifically addressed. New non-vertebrate animal models of infection may facilitate high-throughput screening (HTS) of novel anti-infectives. [Copyright &y& Elsevier]

Sepsis remains the major cause of death in patients with major burn injuries. In the present investigation we evaluated the interaction between burn injuries of varying severity and preexisting distant infection. We used Gram-negative bacteria (Pseudomonas aeruginosa and Proteus mirabilis) that were genetically engineered to be bioluminescent, which allowed for noninvasive, sequential optical imaging of the extent and severity of the infection. The bioluminescent bacteria migrated from subcutaneous abscesses in the leg to distant burn wounds on the back depending on the severity of the burn injury, and this migration led to increased mortality of the mice. Treatment with ciprofloxacin, injected either in the leg with the bacterial infection or into the burn eschar, prevented this colonization of the wound and decreased mortality. The present data suggest that burn wounds can readily become colonized by infections distant from the wound itself. [ABSTRACT FROM AUTHOR]

Burn injury destroys skin, the second largest innate immune organ in the body, and triggers chaotic immune and inflammatory responses. The pattern recognition molecule, mannan-binding lectin (MBL), plays an important role in the first-line host defense against infectious agents. MBL initiates the lectin complement pathway and acts as an opsonin. Recent studies suggest that MBL also modulates inflammatory responses. We report that local responses after burn in MBL null mice differ from those found in wild-type (WT) mice in the following important biological markers: spontaneous eschar separation, thinned epidermis and dermis, upregulation of soluble factors including cytokines, chemokines, cell adhesion molecules, a growth factor-binding protein, and matrix metalloproteinases. Mice lacking C1q, C4, or C3 did not show the lack of eschar separation seen in MBL null-burn phenotype. These findings implicate MBL as an important molecule in the maintenance of the homeostatic balance.Journal of Investigative Dermatology (2007) 127, 1524–1531. doi:10.1038/sj.jid.5700748; published online 15 March 2007 [ABSTRACT FROM AUTHOR]

The article focuses on the need for Caution when applying Photobiomodulation Therapy (PBMT) for Hereditary Diseases. Topic include the effect of PBMT in an animal model of Meckel syndrome (MKS), involve Meckel (or Meckel–Gruber) syndrome is a rare type of genetic Polycystic Kidney Disease (PKD) that has effects on the central nervous system and liver.

Spore formation is a sophisticated mechanism by which some bacteria survive conditions of stress and starvation by producing a multilayered protective capsule enclosing their condensed DNA. Spores are highly resistant to damage by heat, radiation, and commonly employed antibacterial agents. Previously, spores have also been shown to be resistant to photodynamic inactivation using dyes and light that easily destroy the corresponding vegetative bacteria. We have discovered that Bacillus spores are susceptible to photoinactivation by phenothiazinium dyes and low doses of red light. Dimethylmethylene blue, methylene blue, new methylene blue, and toluidine blue O are all effective, while alternative photosensitizers such as Rose Bengal, polylysine chlorin(e6) conjugate, a tricationic porphyrin, and a benzoporphyrin derivative, which easily kill vegetative cells, are ineffective. Spores of Bacillus cereus and B. thuringiensis are most susceptible, B. subtilis and B. atrophaeus are also killed, and B. megaterium is resistant. Photoinactivation is most effective when excess dye is washed from the spores, showing that the dye binds to the spores and that excess dye in solution can quench light delivery. The relatively mild conditions needed for spore killing could have applications for treating wounds contaminated by anthrax spores, for which conventional sporicides would have unacceptable tissue toxicity. [ABSTRACT FROM AUTHOR]