Ying-Ying Huang

Massachusetts General Hospital | MGH · Wellman Center for Photomedicine

Purpose Inferior alveolar nerve (IAN) injury is one of the most serious complications after extraction of impacted lower third molars. Photobiomodulation (PBM) therapy has been noted to reduce pain and inflammation while promoting tissue healing. This study examined the efficacy of PBM therapy tested in a case series of patients with postoperative...

Objective: To explore the effectiveness, biosafety, photobleaching and mechanism of antimicrobial photodynamic therapy (aPDT) using methylene blue (MB) plus potassium iodide (KI), for root canal infections. Methods: Different combinations and concentrations of MB, KI and 660 nm LED light were used against E. faecalis in planktonic and in biofilm...

Antimicrobial photodynamic inactivation (aPDI) employs the combination of non‐toxic photosensitizing dyes and visible light to kill pathogenic microorganisms regardless of drug‐resistance, and can be used to treat localized infections. A meso‐substituted tetra‐methylpyridinium porphyrin with one methyl group replaced by a C12 alkyl chain (FS111) an...

We have recently shown that a wide range of different inorganic salts can potentiate antimicrobial photodynamic inactivation (aPDI) and TiO2-mediated antimicrobial photocatalysis. Potentiation has been shown with azide, bromide, thiocyanate, selenocyanate, and most strongly, with iodide. Here we show that sodium nitrite can also potentiate broad-sp...

Drug-resistant urinary tract infections (UTIs) are difficult and sometimes impossible to treat. Many UTIs are caused by uropathogenic Escherichia coli (UPEC). We developed an intact rat model of UTI, by catheterizing female rats and introducing a bioluminescent UPEC strain into the female rat bladder which lasted for up to six days. We recently sho...

Tetracyclines (including demeclocycline, DMCT, or doxycycline, DOTC) represent a class of dual-action antibacterial compounds, which can act as antibiotics in the dark, and also as photosensitizers under illumination with blue or UVA light. It is known that tetracyclines are taken up inside bacterial cells where they bind to ribosomes. In the prese...

Biofilm describes a microbially-derived sessile community in which microbial cells are firmly attached to the substratum and embedded in extracellular polymeric matrix. Microbial biofilms account for up to 80% of all bacterial and fungal infections in humans. Biofilm-associated pathogens are particularly resistant to antibiotic treatment, and thus...

Photobiomodulation (PBM), also known as low‐level laser (light) therapy, was discovered over 50 years ago, but only recently has it been making progress towards 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...

Antimicrobial photodynamic inactivation (aPDI) employs photosensitizing dyes activated by visible light to produce reactive oxygen species. aPDI is independent of the antibiotic resistance status of the target cells, and is thought unlikely to produce resistance itself. Among many PS that have been investigated, tetracyclines occupy a unique niche....

Quantum dot light‐emitting devices (QLEDs), originally developed for displays, were recently demonstrated to be promising light sources for various photomedical applications, including photodynamic therapy cancer cell treatment and photobimodulation cell metabolism enhancement. With exceptional emission wavelength tunability and potential flexibili...

It is known that multiple cationic charges are required to produce broad-spectrum antimicrobial photosensitizers (PS) for photodynamic inactivation (aPDI) or photodynamic therapy of bacteria and fungi. In the present study...

We previously showed that blue (415 nm) and green (540 nm) wavelengths were more effective in stimulating osteoblast differentiation of human adipose-derived stem cells (hASC), compared to red (660 nm) and near-infrared (NIR, 810 nm). Intracellular calcium was higher after blue/green, and could be inhibited by the ion channel blocker, capsazepine....

The alarming worldwide increase in antibiotic resistance amongst microbial pathogens necessitates a search for new antimicrobial techniques, which will not be affected by, or indeed cause resistance themselves. Light-mediated photoinactivation is one such technique that takes advantage of the whole spectrum of light to destroy a broad spectrum of p...

Rose Bengal (RB) is a halogenated xanthene dye that has been used to mediate antimicrobial photodynamic inactivation for several years. While highly active against Gram-positive bacteria, RB is largely inactive in killing Gram-negative bacteria. We have discovered that addition of the non-toxic salt potassium iodide (100mM) potentiates green light...

While OLEDs have struggled to find a niche lighting application that can fully take advantage of their unique form factors as thin, flexible, lightweight and uniformly large-area luminaire, photomedical researchers have been in search of low-cost, effective illumination devices with such form factors that could facilitate widespread clinical applic...

Combating antimicrobial resistance is one of the most serious public health challenges facing society today. The development of new antibiotics or alternative techniques that can help combat antimicrobial resistance is being prioritised by many governments and stakeholders across the globe. Antimicrobial photodynamic therapy is one such technique t...

Photobiomodulation (PBM) describes the use of red or near-infrared (NIR) light to stimulate, heal, and regenerate damaged tissue. Both preconditioning (light delivered to muscles before exercise) and PBM applied after exercise can increase sports performance in athletes. This review covers the effects of PBM on human muscle tissue in clinical trial...

Photobiomodulation (PBM) using red or near-infrared (NIR) light has been used to stimulate the proliferation and differentiation of adipose-derived stem cells. The use of NIR wavelengths such as 810 nm is reasonably well accepted to stimulate mitochondrial activity and ATP production via absorption of photons by cytochrome c oxidase. However, the m...

Unlabelled: Human adipose-derived stem cells (hASCs) have the potential to differentiate into several different cell types including osteoblasts. Photobiomodulation (PBM) or low level laser therapy (LLLT) using red or near-infrared wavelengths has been reported to have effects on both proliferation and osteogenic differentiation of stem cells. We...

This study intended to evaluate the effects of a papain-gel with a red-light absorbing pigment (methylene blue – MB) to mediate photodynamic therapy (PDT) against Streptococcus mutans biofilms. The PapaMBlue was compared with free MB to generate reactive oxygen species using fluorescence probes (SOSG and HPF). PDT (660-nm light) was carried out aga...

Low-level laser (light) therapy (LLLT) for traumatic events that cause brain damage is currently an experimental concept. The broad goals for clinical utilization are the prevention of brain damage, relief of symptoms, and stimulation of the repair process. Experimental studies have tested and continue to test these goals by investigating LLLT in a...

Photocatalysis describes the excitation of titanium dioxide nanoparticles (a wide-band gap semiconductor) by ultraviolet A light, to produce reactive oxygen species (ROS) that can destroy many organic molecules. This photocatalysis process is used for environmental remediation, while antimicrobial photocatalysis can kill many classes of microorgani...

In the article by C. Ferraresi et al. (DOI: http://dx.doi.org/10.1002/jbio.201400087), published in J. Biophotonics 8, 740-754 (2015), a statement regarding the approval of some data the authors used is incorrect. This erratum is published to rectify this.

Antimicrobial photocatalysis involves the UVA excitation of titanium dioxide (TiO2) nanoparticles (particularly the anatase form) to produce reactive oxygen species (ROS) that kill microbial cells. For the first time we report that the addition of sodium bromide to photoactivated TiO2 (P25) potentiates the killing of Gram-positive, Gram-negative ba...

Photodynamic therapy (PDT) employs the combination of nontoxic photosensitizers (PS) and visible light that, after light absorption, can produce long-lived excited triplet states of the chromophore, that are able to carry out a sequence of photochemical reactions in the presence of oxygen to produce reactive oxygen species (ROS). These photoinduced...

Photodynamic therapy (PDT) employs non-toxic dyes called photosensitizers, which absorb visible light to give the excited singlet state, followed by the long-lived triplet state that can undergo photochemistry. In the presence of ambient oxygen, reactive oxygen species such as singlet oxygen and hydroxyl radicals are formed that are able to kill ca...

Since the discovery of C60 fullerene in 1985, scientists have been searching for biomedical applications of this most fascinating of molecules. The unique photophysical and photochemical properties of C60 suggested that the molecule would function well as a photosensitizer in photodynamic therapy (PDT). PDT uses the combination of non-toxic dyes an...

The relentless advance of drug-resistance among pathogenic microbes, mandates a search for alternative approaches that will not cause resistance. Photodynamic inactivation (PDI) involves the combination of nontoxic dyes with harmless visible light to produce reactive oxygen species that can selectively kill microbial cells. PDI can be broad-spectru...

Photodynamic therapy (PDT) uses non-toxic dyes called photosensitizers (PS) to absorb light of visible or near-infrared wavelengths at non-thermal power densities that (in the presence of oxygen) combine together to produce reactive oxygen species (ROS). The main ROS formed are singlet oxygen and hydroxyl radicals that can both have cytotoxic effec...

Recently, low-level laser (light) therapy has been used to increase muscle performance in intense exercises. However, there is a lack of understanding of the time response of muscles to light therapy. The first purpose of this study was to determine the time response for light-emitting diode therapy (LEDT)-mediated increase in adenosine triphosphat...

This chapter briefly covers the signs and symptoms of all the most common and important neural pathologies that may occur in the head and neck region, and particularly in the oral cavity. It particularly concentrates on treatment directed at improving the injured nerve responses by stimulating them with light. Light is a very versatile tool when us...

Antimicrobial photodynamic therapy (aPDT), also known as photodynamic inactivation (PDI), photoactivated disinfection (PAD) or photodynamic antimicrobial chemotherapy (PACT), involves the administration of a photoactive dye or photosensitizer (PS) that can produce reactive oxygen species (ROS) upon irradiation with light of the correct wavelength t...

The research interests of the Hamblin laboratory are broadly centered on the use of different kinds of light to treat many different diseases. Photodynamic therapy (PDT) uses the combination of dyes with visible light to produce reactive oxygen species and kill bacteria, cancer cells and destroy unwanted tissue. Likewise UV light is also good at ki...

Melanoma is a dreaded form of skin cancer caused by the malignant transformation of skin melanocytes and can be highly aggressive and has a rapidly growing incidence and elevated mortality and a poor prognosis at an advanced stage. Because melanomas are intrinsically resistant to conventional radiotherapy and chemotherapy, many alternative treatmen...

Low level laser (light) therapy has been used before exercise to increase muscle performance in both experimental animals and in humans. However uncertainty exists concerning the optimum time to apply the light before exercise. The mechanism of action is thought to be stimulation of mitochondrial respiration in muscles, and to increase adenosine tr...

Three functionalized C60 fullerenes with a decacationic arm were synthesized and characterized.•These compounds were used to photoinactivate Gram-positive, Gram-negative bacteria and a fungal yeast when excited by UVA or white light.•Addition of sodium azide potentiated photoinactivation especially in the absence of oxygen.•Addition of azide increa...

Light-emitting diode therapy (LEDT) applied over the leg, gluteus and lower-back muscles of mice using a LED cluster (630 nm and 850 nm, 80 mW/cm(2) , 7.2 J/cm(2) ) increased muscle performance (repetitive climbing of a ladder carrying a water-filled tube attached to the tail), ATP and mitochondrial metabolism; oxidative stress and proliferative my...

Excitotoxicity describes a pathogenic process whereby death of neurons releases large amounts of the excitatory neurotransmitter glutamate, which then proceeds to activate a set of glutamatergic receptors on neighboring neurons (glutamate, N-methyl-D-aspartate (NMDA), and kainate), opening ion channels leading to an influx of calcium ions producing...

In this study, we investigated the utility of antimicrobial blue light therapy for multidrug-resistant Acinetobacter baumannii infection in a mouse burn model. A bioluminescent clinical isolate of multidrug-resistant A. baumannii was obtained. The susceptibility of A. baumannii to blue light (415 nm)–inactivation was compared in vitro to that of hu...

We designed, synthesized, and characterized two types of highly water-soluble C70 monoadduct, C70[>M(C 3N6+C3)2]-(I -)10 (LC17), and bisadducts, C70[>M(C 3N6+C3)2][>M(C 3N6C3)2] (LC18). Each of these compounds consist of a well-defined decacationic quaternary ammonium iodide moiety with ten positive charges per C70 for increasing water-solubility a...

Wound care is an important area of medicine considering the increasing age of the population who may have diverse comorbidities. Light-based technology comprises a varied set of modalities of increasing relevance to wound care. While low-level laser (or light) therapy and photodynamic therapy both have wide applications in wound care, this review w...

Bacteriochlorins are attractive candidates as photosensitizers for photodynamic therapy (PDT) due to their intense absorption in the near-infrared (NIR) region of the spectrum where light transmission through tissue is maximal. Many naturally occurring bacteriochlorins are inherently unstable due to adventitious atmospheric oxidation. A de novo syn...

Microbial biofilms are responsible for a variety of microbial infections in different parts of the body, such as urinary tract infections, catheter infections, middle-ear infections, gingivitis, caries, periodontitis, orthopedic implants, and so on. The microbial biofilm cells have properties and gene expression patterns distinct from planktonic ce...

Photodynamic therapy (PDT) employs the combination of non-toxic photosensitizers (PS) together with harmless visible light of the appropriate wavelength to produce reactive oxygen species that kill unwanted cells. Because many PS are hydrophobic molecules prone to aggregation, numerous drug delivery vehicles have been tested to solubilize these mol...

Background: Antimicrobial photodynamic therapy uses photosensitizers designed to bind to microorganisms and generate reactive oxygen species when illuminated with visible light. Materials & methods: We synthesized a highly water-soluble [70]fullerene monoadduct, C70[>M(C3N6(+)C3)2]-(I(-))10 (LC17), and bisadduct, C70[>M(C3N6(+)C3)2][>M(C3N6C3)2]...

Unlabelled: Fullerenes are promising candidates for photodynamic therapy (PDT). Thus, C₇₀ and novel C₈₄O₂ fullerenes were functionalized with and without an additional deca-tertiary ethyleneamino-chain as an electron source, giving rise to two distinct pairs of photosensitizers, the monoadducts LC-17, LC-19 and the bisadducts LC18 and LC-20 to per...

Antimicrobial photodynamic therapy (PDT) or photodynamic inactivation (PDI) is a new promising strategy to eradicate pathogenic microorganisms such as Gram-positive and Gram-negative bacteria, yeasts and fungi. The search for new approaches that can kill bacteria but do not induce the appearance of undesired drug-resistant strains suggests that PDT...

Conventional antimicrobials are increasingly ineffective due to the emergence of multidrug-resistance among pathogenic microorganisms. The need to overcome these deficiencies has triggered exploration for novel and unconventional approaches to controlling microbial infections. Multidrug efflux systems (MES) have been a profound obstacle in the succ...

We have previously shown that transcranial low level light therapy (LLLT) can ameliorate brain damage in mice subjected to traumatic brain injury and improve neurological function. We used 810-nm laser and delivered 18 J/cm2 at an irradiance 25 mW/cm2. LLLT was either delivered once at 4 hours after controlled cortical impact TBI, once a day for 3...

Background and objective: Bacterial skin and soft tissue infections (SSTI) affect millions of individuals annually in the United States. Treatment of SSTI has been significantly complicated by the increasing emergence of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) strains. The objective of this study was to demonstrate...

Abstract Melanoma is the most dangerous form of skin cancer, with a steeply rising incidence and a poor prognosis in its advanced stages. Melanoma is highly resistant to traditional chemotherapy and radiotherapy, although modern targeted therapies such as BRAF inhibitors are showing some promise. Photodynamic therapy (PDT, the combination of photos...

Introduction: Discovery of novel drugs, treatments, and testing of consumer products in the field of dermatology is a multi-billion dollar business. Due to the distressing nature of many dermatological diseases, and the enormous consumer demand for products to reverse the effects of skin photodamage, aging, and hair loss, this is a very active fie...