Search

Background Smart nanoscale drug delivery systems that target acidic tumor microenvironments (TME) could offer controlled release of drugs and modulate the hypoxic TME to enhance cancer therapy. The majority of previously reported MnO2 nanostructures are nanoparticles, nanosheets, or nanocomposites incorporated with other types of nanoparticles, which may not offer the most effective method for drug loading or for the controlled release of therapeutic payloads. Previous studies have designed MnO2 nanoshells that achieve tumor-specific and enhanced combination therapy for localized advanced cancer. However, the therapeutic effect of MnO2 nanoshells on metastatic cancer is still uncertain. Result Here, intelligent “theranostic” platforms were synthesized based on hollow mesoporous MnO2 (H-MnO2) nanoshells that were loaded with chemotherapy agents docetaxel and cisplatin (TP) to form H-MnO2-PEG/TP nanoshells, which were designed to alleviate tumor hypoxia, attenuate angiogenesis, trigger the dissolution of Mn2+, and synergize the efficacy of first-class anticancer chemotherapy. The obtained H-MnO2-PEG/TP nanoshells decomposed in the acidic TME, releasing the loaded drugs (TP) and simultaneously attenuated tumor hypoxia and hypoxia-inducible factor-1α (HIF-1α) expression by inducing endogenous tumor hydrogen peroxide (H2O2) decomposition. In vitro experiments showed that compared with the control group, the proliferation, colony formation and migration ability of CAL27 and SCC7 cells were significantly reduced in H-MnO2-PEG/TP group, while cell apoptosis was enhanced, and the expression of hypoxia-inducible factor-1α(HIF-1α) was down-regulated. In vivo experiments showed that tumor to normal organ uptake ratio (T/N ratio) of mice in H-MnO2-PEG/TP group was significantly higher than that in TP group alone (without the nanoparticle), and tumor growth was partially delayed. In the H-MnO2-PEG/TP treatment group, HE staining showed that most of the tumor cells were severely damaged, and TUNEL assay showed cell apoptosis was up-regulated. He staining of renal and liver sections showed no obvious fibrosis, necrosis or hypertrophy, indicating good biosafety. Fluorescence staining showed that HIF-1α expression was decreased, suggesting that the accumulation of MnO2 in the tumor caused the decomposition of H2O2 into O2 and alleviated the hypoxia of the tumor. Conclusion In conclusion, a remarkable in vivo and in vitro synergistic therapeutic effect is achieved through the combination of TP chemotherapy, which simultaneously triggered a series of antiangiogenic and oxidative antitumor reactions. Graphic abstract

Background The relationship between spinal sagittal subtypes and lumbar disc degeneration is unclear. Thus, we aimed to investigate the relationship between lumbar intervertebral disc degeneration and age in asymptomatic healthy individuals with different sagittal alignments. Methods In this cross-sectional observational study, we examined 209 asymptomatic young and middle-aged volunteers (123 women and 86 men) who were divided into the following three groups according to age: groups A (20–30 years), B (31–40 years), and C (41–50 years). The volunteers underwent full-spine standing lateral radiography and magnetic resonance imaging (MRI, 3.0 T) of the lumbar spine. Based on panoramic radiography, two observers measured the spinopelvic parameters and classified the spine into Roussouly subtypes. The degree of disc degeneration was assessed based on T2-weighted images according to the Pfirrmann classification. Results There was a statistically significant difference in the degree of degeneration of type I spine between groups B and C at L4-L5 (P P P P P P P Conclusion The different spinal subtypes have characteristics of lumbar disc degeneration at specific levels with age. We considered that spinal classification could be used as a predictor of lumbar disc degeneration. Our data may be helpful to increase awareness of the relationship between spinal subtypes and lumbar disc degeneration. Level of evidence 3

Large areas of soil are boron (B) deficient and contaminated with cadmium (Cd) in southern China. The aim of this study was to select the optimal B supply level and elucidate the underlying physiological and biochemical mechanisms to understand how B reduces Cd influx into root cells of hot pepper (Capsicum annuum). An experiment was conducted to investigate the changes in Cd accumulation with B supply. Hot pepper seedlings were grown in two nutrient solutions containing 0.05- and 0.2-mg Cd L-1 and supplied with six different B concentrations for 2 weeks. The other experiment was conducted to determine the Cd2+ flux into cells, cell wall components, antioxidative ability, and plasmalemma permeability of root tips of hot pepper exposed to 0.1-mg Cd L-1 in the presence and absence of B. The results showed that the optimal B concentration to promote plant growth and reduce Cd accumulation was 0.25 mg L-1. Moreover, B application significantly decreased Cd2+ influx into cells, increased the contents of lignin and pectin, enhanced the activities of antioxidant enzymes, reduced the production of reactive oxygen species, and decreased membrane peroxidation and permeability. Overall, boron in moderation can promote plant growth, maintain the normal structures and functions of the cell wall and membrane, and thus decrease Cd2+ influx into root cells and subsequently Cd translocation to shoots. Consequently, B is a reliable inhibitor of Cd uptake, and the functional and structural integrity of cell walls and membranes may have some relevance to reduced Cd uptake after B application.

Two new sesquiterpenes ( 1 and 2 ), one new alkaloid ( 4 ), one new neolignan glycoside ( 14 ), together with 19 known compounds were isolated from the branches of Alangium barbatum . Their structures were established by spectroscopic analysis. The absolute configuration of 21 was determined for the first time by single-crystal X-ray diffraction analysis with Cu-Kα irradiation. Some of isolates were evaluated for their inhibitory effects on NO production in LPS-induced RAW264.7 macrophages. Compounds 1 , 3 and 9 at 10 μM concentrations exhibited mild inhibitory effects on NO production in the range of 25.0 to 32.4. Moreover, these compounds at 25 μM concentration were also found to mildly suppress NF-κB activation in TNF-α induced expression of NF-κB-Luc in Hela cells with inhibition percent in the range of 15.0 to 25.0%.

To explore the possible roles of metallothioneins (MTs) played in cadmium (Cd) accumulation of water spinach, three IaMT genes, IaMT1, IaMT2 and IaMT3 in a high-shoot-Cd (T308) and a low-shoot-Cd accumulation cultivar (QLQ) were cloned, characterized, and quantitated. Gene expression analysis suggested that the expression of the IaMTs was differentially regulated by Cd stress in different cultivars, and T308 showed higher MTs expression overall. Furthermore, only shoot IaMT3 expression was cultivar dependent among the three IaMTs. Antioxidant analysis showed that the high production of IaMTs in T308 should be associated with its high oxidation resistance. The role of IaMTs in protecting against Cd toxicity was demonstrated in vitro via recombinant E. coli strains. The results showed that IaMT1 correlated with neither Cd tolerance nor Cd accumulation of E. coli, while IaMT2 conferred Cd tolerance in E. coli, IaMT2 and IaMT3 increased Cd accumulation in E. coli. These findings help to clarify the roles of IaMTs in Cd accumulation, and increase our understanding of the cultivar-dependent Cd accumulation in water spinach.

Background Foam sclerotherapy is an effective treatment strategy for venous malformations (VMs). Stability is one of the characteristics of sclerosant foams that determine the sclerosing power. Objective To evaluate the clinical outcomes of sclerotherapy with prolonged half-life of hyaluronic acid (HA)-polidocanol (POL) foam for treating head and neck VMs. Materials and methods Seventy patients with head and neck VMs were enrolled between October 2013 and January 2015 in Qilu Hospital Shandong University. Sclerotherapy was performed with prolonged half-life POL foam by addition of 0.05% HA. All patients were followed up at 1, 3, and 6 months. Reviews on the site and size of the lesion, times and duration of treatments, therapeutic response, and complications were performed to evaluate the end result. Results Sites of lesions included face, bucca, parotid region, neck, tongue, floor of mouth, lip, forehead, palate, and nose. An overall average of 2.5 treatments was required. Total response rate was 100%. "Resolution" was achieved in 21 cases (30%) and a significant response in 49 patients (70%). Immediate swelling was the most common complication. Epidermal extravasation was seen in 1 patient. Mucosal ulcer was observed in 1 patient. No generalized complications occurred. Conclusion The prolonged half-life of HA-POL foam sclerotherapy of VMs in the head and neck is safe and effective.

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 present study, we investigated the photochemical mechanism: Type 1 (hydroxyl radicals); Type 2 (singlet oxygen); or Type 3 (oxygen independent). Moreover, we asked whether addition of potassium iodide (KI) could potentiate the aPDI activity of tetracyclines. High concentrations of KI (200–400 mM) strongly potentiated (up to 5 logs of extra killing) light-mediated killing of Gram-negative Escherichia coli or Gram-positive MRSA (although the latter was somewhat less susceptible). KI potentiation was still apparent after a washing step showing that the iodide could penetrate the E. coli cells where the tetracycline had bound. When cells were added to the tetracycline + KI mixture after light, killing was observed in the case of E. coli showing formation of free molecular iodine. Addition of azide quenched the formation of iodine but not hydrogen peroxide. DMCT but not DOTC iodinated tyrosine. Both E. coli and MRSA could be killed by tetracyclines plus light in the absence of oxygen and this killing was not quenched by azide. A mouse model of a superficial wound infection caused by bioluminescent E. coli could be treated by topical application of DMCT and blue light and bacterial regrowth did not occur owing to the continued anti biotic activity of the tetracycline.

Impaired left atrial appendage ejection fraction (LAA-EF) and peak LAA flow velocity (LAA-FV) are associated with high thromboembolic risks in patients with atrial fibrillation (AF). Herein, we examined LAA function among patients with atrial flutter (AFL) stratified by the CHA2DS2-VASc score using transesophageal echocardiography (TEE). Of 231 consecutive patients with typical AFL, 84 who fulfilled the inclusion criteria were enrolled. Among them, 57 had ongoing AFL and were divided into the isolated AFL (n = 38) and AFL with paroxysmal AF (PAF) (n = 19) groups, depending on whether they had sporadic AF before TEE. The remaining 27 patients with spontaneous sinus rhythm during TEE were designated as controls. Both the LAA-FV (31.9 cm/s vs. 51.5 cm/s, P = 0.004) and LAA-EF (28.4% vs. 36.5%, P = 0.024) measured during AFL were significantly lower in the AFL + PAF group than in the isolated AFL group. Significant inverse correlations between the CHA2DS2-VASc score and LAA-EF were identified in the AFL (P = 0.008) and AFL + PAF (P = 0.032) groups. We observed progressive LAA dysfunction in patients with AFL + PAF compared with that in patients with isolated AFL, and the LAA-EF was inversely correlated with the CHA2DS2-VASc score in these patients. Our findings may have implications on the application of thromboprophylactic therapy in patients with AFL.

Purpose The management of extensive head and neck lymphatic malformations (LMs) in infants is challenging because of life-threatening upper airway compression. The aim of this study was to present a management protocol and evaluate the clinical outcomes for preventing tracheotomy in these patients. Materials and Methods Fifteen infants with extensive head and neck LMs and airway involvement were enrolled from August 2010 through September 2015 at the Qilu Hospital of Shandong University (Jinan, China). According to various key factors associated with airway compression of patients in the perioperative period, different anesthesia types, treatment times, sclerosant concentrations, and sclerotherapy protocols were used. Multistage sclerotherapy was performed with bleomycin A5. All patients were followed at 1, 3, 6, and 12 months. More extended follow-up was offered if patients had a residual lesion requiring supplementary sclerotherapy. Reviews on the site and size of the lesion, times and durations of treatments, therapeutic response, airway complications, and conduction of tracheotomy were performed. Results LM lesions in the head and neck were located in the floor of the mouth, tongue, and neck. An overall average of 5 treatments was required; a lesion volume decrease of more than 50% was achieved in all patients. For efficacy, morphologic resolution was achieved in 3 of 15 cases (20%), and there was a substantial response in 12 of 15 cases (80%). Eight of 15 patients (53.3%) with microcystic LMs exhibited immediate swelling and had more serious upper airway symptoms than preoperatively, and 2 of 15 patients (13.3%) had feeding difficulty. No upper airway obstruction occurred and no tracheotomy was performed in the patients in this study. Conclusions Multistage sclerotherapy with bleomycin A5 is a safe and effective treatment for extensive head and neck LMs in infants with airway involvement. A routine perioperative protocol is essential for decreasing airway complications.

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. In the present study we asked what was the effect of these four wavelengths on proliferation of the hASC? When cultured in proliferation medium there was a clear difference between blue/green which inhibited proliferation and red/NIR which stimulated proliferation, all at 3 J/cm2. Blue/green reduced cellular ATP, while red/NIR increased ATP in a biphasic manner. Blue/green produced a bigger increase in intracellular calcium and reactive oxygen species (ROS). Blue/green reduced mitochondrial membrane potential (MMP) and lowered intracellular pH, while red/NIR had the opposite effect. Transient receptor potential vanilloid 1 (TRPV1) ion channel was expressed in hADSC, and the TRPV1 ligand capsaicin (5uM) stimulated proliferation, which could be abrogated by capsazepine. The inhibition of proliferation caused by blue/green could also be abrogated by capsazepine, and by the antioxidant, N-acetylcysteine. The data suggest that blue/green light inhibits proliferation by activating TRPV1, and increasing calcium and ROS.

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 that has received considerable attention but is limited by the inability of light to penetrate through human tissue, reducing its effectiveness when used to treat deep-seated infections. The related technique sonodynamic therapy (SDT) has the potential to overcome this limitation given the ability of low-intensity ultrasound to penetrate human tissue. In this study, a Rose Bengal–antimicrobial peptide conjugate was prepared for use in antimicrobial SDT (ASDT). When Staphylococcus aureus and Pseudomonas aeruginosa planktonic cultures were treated with the conjugate and subsequently exposed to ultrasound, 5 log and 7 log reductions, respectively, in bacterial numbers were observed. The conjugate also displayed improved uptake by bacterial cells compared with a mammalian cell line ( P ≤ 0.01), whilst pre-treatment of a P. aeruginosa biofilm with ultrasound resulted in a 2.6-fold improvement in sensitiser diffusion ( P ≤ 0.01). A preliminary in vivo experiment involving ASDT treatment of P. aeruginosa -infected wounds in mice demonstrated that ultrasound irradiation of conjugate-treated wounds affects a substantial reduction in bacterial burden. Combined, the results obtained from this study highlight ASDT as a targeted broad-spectrum novel modality with potential for the treatment of deep-seated bacterial infections.

To investigate the age-dependent impact of the superfast door-to-balloon (D2B) times of ≤60min as recommended by the new ESC Guideline for patients with ST elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI) on mid-term survival rates based on a single center registry dataset.This study enrolled consecutive STEMI patients who underwent PPCI from Jan 1, 2009 through Sep 30, 2013. We compared demographics, clinical characteristics and the D2B-survival relationships between patients aged ≥65 and65.The younger group comprised 242 patients (68%) aged65 and the elder group consisted of 115 patients (32%) aged ≥65. In patients aged65, the mortality rate decreased linearly with D2B time shortening (90min vs. 61-90min vs. ≤60min=14.9% vs. 13.3% vs. 1.2%, P=0.001). Contrarily, shortening of D2B time was not associated with reduced mortality rate in patients aged ≥65 (90min vs. 61-90min vs. ≤60min=23.5% vs. 19% vs. 18.9%, P=0.99). In younger patients but not the elderly, a D2B time of60min has sufficient power to predict mortality with a sensitivity of 0.83, specificity of 0.74, and Youden index of 0.57.Our results show that the new ESC Guideline recommendation of D2B time ≤60min is associated with better survival rates in younger STEMI patients undergoing PPCI. Our findings stress the importance of guideline adherence to minimize reperfusion delay to improve survival in these patients.

Photodynamic therapy involves the excitation of a non-toxic dye by harmless visible light to produce a long-lived triplet state that can interact with molecular oxygen to produce reactive oxygen species (ROS), which can damage biomolecules and kill cells. ROS produced by electron transfer (Type 1) include superoxide, hydrogen peroxide and hydroxyl radical (HO), while singlet oxygen (1O2) is produced by energy transfer. Diverse methods exist to distinguish between these two pathways, some of which are more specific or more sensitive than others. In this review we cover the use of two fluorescence probes: singlet oxygen sensor green (SOSG) detects 1O2; and 4-hydroxyphenyl-fluorescein (HPF) that detects HO. Interesting data was collected concerning the photochemical pathways of functionalized fullerenes compared to tetrapyrroles, stable synthetic bacteriochlorins with and without central metals, phenothiazinium dyes interacting with inorganic salts such as azide.

Homogeneous, flexible light sources with pure, deep red color and sufficiently high power densities are necessary for more effective and widely used photodynamic therapy (PDT), but have been difficult to achieve with lasers or LED arrays at reasonably low cost. Quantum dot light emitting diodes (QLEDs) have outstanding wavelength tunability, ideal color purity, sufficient power density and unique form factors as thin, flexible, light weight and uniformly large area light sources, which will meet the pressing needs for PDT. Here we report QLEDs fabricated with emission wavelengths precisely tuned to match the absorption peaks of several FDA approved photosensitizers. Preliminary in-vitro studies with rigid on-glass QLEDs as photosensitizer activators demonstrate they can kill cancerous A431 cells or Methicillin-resistant Staphylococcus aureus (MRSA) with efficiency comparable or better than control LED sources, indicating their potential for PDT treatments of cancers or infections. Computer simulation of light propagation in a tissue mimicking phantom suggests that about 50% of the QLED power can be delivered to a depth of about 4 mm from the treated surface. Recent progress on the fabrication of low-cost flexible QLEDs will be presented. Finally, the perspectives of using these devices for PDT to address medical conditions such as cancer treatment, wound repair or cosmetic dermatology will be discussed.

Catheter–associated urinary tract infections (CAUTIs) cause millions of infections in the US every year, with direct medical costs exceeding billions of dollars and resulting in > 1 million ER visits and hospitalizations, resulting in thousands of deaths. CAUTI is thought to be a major reservoir both containing and creating highly drug-resistant infections, due to the chronicity of infection, biofilm formation, and the setting of institutionalization with chronic exposure to antibiotics, thus enabling resistance. To reduce antibiotic resistance developing in this setting, we are attempting to apply both antimicrobial photodynamic therapy (aPDT), antimicrobial blue light (aBL), and combinations of both with minimal use of antibiotics. To this end, we established a rat model of UTI. In this model, we catheterized female rats, infected them with a standard uropathogenic E.Coli (UPEC; UTI89), infused the bladder with methylene blue (MB) and potassium Iodide (KI), and illuminated the bladder once with a diffusing fiber connected to a 1W 660nm laser. Multilog killing was observed, but given the transient nature of ROS generation, regrowth of UPEC was seen 24 hours later. To this end, we are experimenting with the combination of illumination with antibiotics. When tetracyclines are illuminated by aBL, we have found > 6 log(10) steps of microbial killing in vitro, and significant drops in the antibiotic MIC effected by the combination of light and drug. Multiple treatments with aBL and aPDT both with and without limited intravesical application of antimicrobials may light the way to solving this problem.

Photobiomodulation (PBM) with near-infrared light (810 nm laser) has been shown to have marked effects on neuronal cells. In this chapter, three papers, all using the same model, of primary cultured mouse cortical neurons are discussed. In the first paper, the biphasic and triphasic dose response curves of light on reactive oxygen species, nitric oxide release, mitochondrial membrane potential (MMP), intracellular calcium, and ATP were measured. In the second paper, the ability of PBM to reverse the damaging effects of oxidative stress caused by three different agents (cobalt chloride, hydrogen peroxide, and rotenone) was investigated. In the third paper, the excitotoxicity effects produced by three different neurotransmitters like molecules (glutamate, N -methyl- d -aspartate, and kainate) were reversed by PBM. Excessive calcium and reactive oxygen species levels were lowered in injured cells while they were elevated in normal cells. In all cases, the MMP and ATP levels were increased by PBM.

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) and its Pd-derivative (FS111-Pd) were synthesized and tested as broad-spectrum antimicrobial photosensitizers when excited by blue light (5 or 10 J/cm(2)). Both compounds showed unprecedented activity, with the superior FS111-Pd giving 3 logs of killing at 1 nM, and eradication at 10 nM for Gram-positive methicillin-resistant Staphylococcus aureus. For the Gram-negative Escherichia coli, both compounds produced eradication at 100 nM, while against the fungal yeast Candida albicans, both compounds produced eradication at 500 nM. Both compounds could be categorized as generators of singlet oxygen (Φ(Δ) = 0.62 for FS111 and 0.71 for FS111-Pd). An in vivo study was carried out using a mouse model of localized infection in a partial thickness skin abrasion caused by bioluminescent Gram-negative uropathogenic E. coli. Both compounds were effective in reducing bioluminescent signal in a dose-dependent manner when excited by blue light (405 nm), but aPDI with FS111-Pd was somewhat superior both during light and in preventing recurrence during the six days following PDT.

Brain-derived neurotrophic factor (BDNF), a crucial member of the neurotrophic family, is most widely distributed and extensively studied in the mammalian central nervous system. Accumulating evidence from animal and human studies indicates that BDNF plays critical roles in regulating neurogenesis, synaptogenesis and plasticity, and neurological diseases. In this review, we summarize the synthesis and general signaling pathway of BDNF and review its pivotal roles in neurogenesis and the maintenance of axon and dendrites, synaptic transmission and plasticity, which are thought to be the cellular basis for learning and memory, and certain neurological diseases, including Alzheimer’s disease, Parkinson’s disease and Huntington’s disease. Future studies should focus on understanding the multifunctional roles of BDNF in different brain regions and tightly controlled clinical studies.

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 describe the synthesis and aPDI testing of a set of derivatives prepared from the parent pheophytin molecule with different numbers of attached sidearms (1–3) each consisting of five quaternized cationic groups (pentacationic), producing corresponding [Zn(+2)]pheophorbide-a-N(C(2)N(+)C(1)C(3))(5) (Zn-Phe-N(5)(+), 5 charges), [Zn(+2)]chlorin e(6)-[N(C(2)N(+)C(1)C(3))(5)](2) (Zn-Chl-N(10)(+), 10 charges) and [Zn(+2)]mesochlorin e(6)-[N(C(2)N(+)C(1)C(3))(5)](3) (Zn-mChl-N(15)(+), 15 charges). Moreover, a conjugate between Zn-Phe-N(5)(+) and the antibiotic vancomycin called Van-[Zn(+2)]-m-pheophorbide-N(C(2)N(+)C(1)C(3))(5) (Van-Zn-mPhe-N(5)(+)) was also prepared. The aPDI activities of all compounds were based on Type-II photochemistry ((1)O(2) generation). We tested these compounds against Gram-positive methicillin Staphylococcus aureus (MRSA), Gram-negative Escherichia coli, and fungal yeast Candida albicans. All three compounds were highly active against MRSA giving eradication (≥ 6 logs of killing) with < 1.0 μM and 10 J/cm(2) of 415 nm light. The order of activity was Zn-Phe-N(5)(+) > Zn-Chl-N(10)(+) > Zn-mChl-N(15)(+). In the case of E coli the activity was much lower (eradication was only possible with 50 μM Zn-mChl-N(15)(+) and 20 J/cm(2)). The order of activity was the reverse of that found with MRSA (Zn-mChl-N(15)(+) > Zn-Chl-N(10)(+) > Zn-Phe-N(5)(+)). Activity against C. albicans was similar to E. coli with Zn-mChl-N(15)(+) giving eradication. The activity of Van-Zn-mPhe-N(5)(+) was generally lower than Zn-Phe-N(5)(+) (except for E. coli). Red (660 nm) light was also effective as might be expected from the absorption spectra. An initial finding that Van-Zn-mPhe-N(5)(+) might have higher activity against vancomycin resistant Enterococcus fecium (VRE) strains (compared to vancomycin sensitive strains) was disproved when it was found that VRE strains were also more sensitive to aPDI with Zn-Phe-N(5)(+). The minimum inhibitory concentrations of Van-Zn-mPhe-N(5)(+) were higher than Van alone, showing antibiotic properties of the Van moiety were lessened in the conjugate. In conclusion Zn-Phe-N(5)(+) is a highly active PS against Gram-positive species and deserves further testing. Increasing the number of cationic charges increased aPDI efficacy on C. albicans and Gram-negative E. coli.

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 novel antibiofilm approaches needed to be developed. Antimicrobial Photodynamic therapy (aPDT) had been recently proposed to combat clinically relevant biofilms such as dental biofilms, ventilator associated pneumonia, chronic wound infections, oral candidiasis, and chronic rhinosinusitis. aPDT uses non-toxic dyes called photosensitizers (PS), which can be excited by harmless visible light to produce reactive oxygen species (ROS). aPDT is a multi-stage process including topical PS administration, light irradiation, and interaction of the excited state with ambient oxygen. Numerous in vitro and in vivo aPDT studies have demonstrated biofilm-eradication or substantial reduction. ROS are produced upon photo-activation and attack adjacent targets, including proteins, lipids, and nucleic acids present within the biofilm matrix, on the cell surface and inside the microbial cells. Damage to non-specific targets leads to the destruction of both planktonic cells and biofilms. The review aims to summarize the progress of aPDT in destroying biofilms and the mechanisms mediated by ROS. Finally, a brief section provides suggestions for future research.

Antimicrobial photodynamic inactivation (aPDI) is a new approach to killing microbial cells involving the excitation of photosensitizers (PS) by the correct wavelength of light to produce microbicidal reactive oxygen species. aPDI is independent of the antibiotic resistance status of the target cells, and is thought unlikely to produce resistance itself. Among a wide range of antimicrobial PS that have so far been investigated, tetracyclines occupy a unique niche. They are potentially dual-action compounds that can both kill bacteria under illumination, and prevent bacterial regrowth by inhibiting ribosomes. Demeclocycline (DMCT) can be efficiently activated by blue light (405 nm), while doxycycline (DOTC) is excited best by UVA light (360 nm). Both compounds were able to eradicate Gram-positive and Gram-negative bacteria at concentrations up to (100µM) and fluences up to 10J/cm2. The addition of potassium iodide (400mM) potentiates bacteria killing by up to six extra logs with little amount of DMCT and DOTC (5µM). In contrast to methylene blue (MB), tetracyclines can photoinactivate bacteria in rich growth medium. Bacteria regrowth inhibition and even further bacterial killing were observed when bacteria were partially killed with photosensitized DOTC or DMCT, while MB allowed complete regrowth. MIC studies were carried out either in the dark or exposed to continuous blue light (0.5mW/cm2). Up to 3 extra steps (8-fold) of antibiotic activity was found in the light compared to dark, while 5 extra steps (32-fold) of that was observed with 200mM KI. The mechanism is proposed to be singlet oxygen addition to iodine anion to form peroxyiodine which can decomposes into hydrogen peroxide and molecular iodine.

20.1 Disappointment at Current Lack of Progress Despite the impressive accomplishments that have steadily accumulated since the 1960s that now consist of the publication of thousands of peer-reviewed papers [that can be retrieved by a PubMed search using the MeSH term “LLLT” and a new MeSH term “photobiomodulation therapy” (PBM)] and hundreds of clinical trials, many of which have been high-quality, randomized, and well-controlled, LLLT has still not reached the stage of acceptance by mainstream medicine. There remains considerable skepticism (and sometimes frank disbelief) amongst biomedical scientists, the medical profession, and the public at large. The reasons for this skepticism and disbelief are many and various, and they differ depending on the source. Biomedical scientists often refer to a lack of mechanism and the absence of agreement on dosimetry and parameters. Physicians often claim there is a lack of large clinical trials and not enough systematic reviews. Hospital and insurance administrators cannot agree on coverage and reimbursement. Finally (and regrettably), there has been marketing hype, over-promising, and frank misinformation from some of the companies that make devices (lasers, LED arrays, mixed clusters) that are used in the LLLT industry.

b]15.1 Effects of LLLT on Skin 15.1.1 Skin rejuvenation Skin aging is a process that can present itself relatively early on in life, sometimes even as soon as 20 - 30 years of age. Common signs and symptoms associated with skin aging include skin wrinkling, skin dyspigmentation, telangiectasia, and reduced tissue elasticity. At the histological and molecular level, common noticeable features include a reduction in collagen content, fragmentation of collagen fibers, elastotic degeneration of elastic fibers, the appearance of dilated and tortuous dermal vessels, disorientation and atrophy of the epidermis, and up-regulation of matrix metalloproteinases (MMPs), especially MMP-1 and MMP-2. Skin aging can be influenced by both time (normal aging) and environmental factors, but the single most influential factor responsible for accelerated skin aging is believed to be ultraviolet (UV) radiation-induced photodamage.

The lymphatic system plays a critical role in the process of reducing inflammation and edema, as well as a major role in the immune response. It moves fluid (lymph) from interstitial spaces in tissues via a network of collecting vessels to the lymph nodes, where it is mostly emptied into the venous system. Some fluid moves further along the lymphatic chain to other lymph nodes and eventually empties into the thoracic duct. PBM reduces swelling, and it seems likely that the lymphatic system is involved, although limited evidence exists to confirm this. A PubMed search for a range of PBM terms (see Chapter 1) AND edema OR oedema OR swelling returns over 50 abstracts. Most of these abstracts are for post-mastectomy lymphedema, post-surgical swelling, acute soft-tissue injury, and arthritic joints. The mechanism by which light affects edema has not been adequately explored, although it makes sense that it should because nitric oxide (NO) modulates lymphatic vessel contraction and subsequent lymph flow, and it has been established that PBM releases stores of NO8–10 and subsequently improves blood flow. As with blood vessels, NO is produced by endothelial nitric oxide synthase (eNOS) in lymphatic endothelial cells, which in turn affects the dilation and force of lymph vessel contractions. Small amounts of NO are produced (by eNOS) when lymph vessels are stretched (by movement or a stretch/massage technique), and this leads to alternating periods of diastolic filling and systolic ejection of lymphangions (the tiny functional units of the collecting lymphatic system). Excessive amounts of NO produced by inducible nitric oxide synthase (iNOS) during inflammation can overwhelm the NO gradients produced by eNOS. The suppression of eNOS by iNOS disrupts the contraction/relaxation cycle in favor of excessive contraction and subsequent reduced flow.

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. They are potentially dual-action compounds that can both kill bacteria under illumination, and prevent bacterial regrowth by inhibiting ribosomes. Tetracycline antibiotics are regarded as bacteriostatic rather than bactericidal. Doxycycline (DOTC) is excited best by UVA light (365 nm) while demeclocycline (DMCT) can be efficiently activated by blue light (415 nm) as well as UVA. Both compounds were able to eradicate Gram-positive (methicillin-resistant Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria (>6 log(10) steps of killing) at concentrations (10–50μM) and fluences (10-20J/cm2). In contrast to methylene blue, MB plus red light, tetracyclines photoinactivated bacteria in rich growth medium. When ~3 logs of bacteria were killed with DMCT/DOTC+light and the surviving cells were added to growth medium, further bacterial killing was observed, while the same experiment with MB allowed complete regrowth. MIC studies were carried out either in the dark or exposed to 0.5mW/cm2 blue light. Up to three extra steps (8-fold) increased antibiotic activity was found with light compared to dark, with MRSA and tetracycline-resistant strains of E. coli. Tetracyclines can accumulate in bacterial ribosomes, where they could be photoactivated with blue/UVA light producing microbial killing via ROS generation.

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 showed that antimicrobial photodynamic inactivation (aPDI) of a bacterial infection mediated by the well-known phenothiazinium salt, methylene blue (MB) could be strongly potentiated by addition of the non-toxic salt potassium iodide (KI). In the intact rat model we introduced MB into the bladder by catheter, followed by KI solution and delivered intravesicular illumination with a diffusing fiber connected to a 1 W 660 nm laser. Bioluminescent imaging of the bacterial burden was carried out during the procedure and for 6 days afterwards. Light-dose dependent loss of bioluminescence was observed with the combination of MB followed by KI, but recurrence of infection was seen the next day in some cases. aPDT with MB + KI gave a significantly shorter duration of infection compared to untreated controls. aPDT with MB alone was the least effective. No signs of aPDT damage to the bladder lining were detected. This procedure to treat urinary tract infections without antibiotics by using already approved pharmaceutical substances (MB and KI) may have clinical applicability, either initially as a stand-alone therapy, or as an adjunct to antibiotic therapy by a rapid and substantial reduction of the bacterial burden.

Background Low-level light therapy (LLLT) is used to stimulate healing, reduce pain and inflammation, and preserve tissue from dying. LLLT has been shown to protect cells in culture from dying after various cytotoxic insults, and LLLT is known to increase the cellular ATP content. Previous studies have demonstrated that maintaining a sufficiently high ATP level is necessary for the efficient induction and execution of apoptosis steps after photodynamic therapy (PDT). Methods We asked whether LLLT would protect cells from cytotoxicity due to PDT, or conversely whether LLLT would enhance the efficacy of PDT mediated by mono- l -aspartyl chlorin(e6) (NPe6). Increased ATP could lead to enhanced cell uptake of NPe6 by the energy dependent process of endocytosis, and also to more efficient apoptosis. In this study, human osteosarcoma cell line MG-63 was subjected to 1.5 J/cm2 of 810 nm near infrared radiation (NIR) followed by addition of 10 μM NPe6 and after 2 h incubation by 1.5 J/cm2 of 652 nm red light for PDT. Results PDT combined with LLLT led to higher cell death and increased intracellular reactive oxygen species compared to PDT alone. The uptake of NPe6 was moderately increased by LLLT, and cellular ATP was increased. The mitochondrial respiratory chain inhibitor antimycin A abrogated the LLLT-induced increase in cytotoxicity. Conclusions Taken together, these results demonstrate that LLLT potentiates NPe6-mediated PDT via increased ATP synthesis and is a potentially promising strategy that could be applied in clinical PDT.

Functionalized fullerenes are gaining wide interest for mediating photodynamic therapy (PDT) of diseases such as cancers and infections. We recently reported the synthesis of two new decacationic fullerene monoadducts: C60[M(C3N6(+)C3)2]-(I(-))10(LC14) and its derivative with a light-harvesting antenna conjugated as a C60[CPAF-(MN6(+)C3)2]-(I(-))10 nanostructure (LC15). We studied the ability of these compounds to mediate PDT of human cancer cells in vitro when excited by UVA light or by white light. Here we report the synthesis of a new fullerene derivative C60[M(C3N6(+)C3)2][M(C3N6C3)2]-(I(-))10 (LC16 derived from LC14), as a malonate bisadduct containing a covalently bound decatertiary amine arm. We investigated the relative abilities of the three compounds to generate singlet oxygen ((1)O2), hydroxyl radicals (HO·), and hydrogen peroxide (H2O2) after excitation by UVA or by white light. We used three different classes of pathogenic microbial cells (Gram-positive bacterium, methicillin-resistant Staphylococcus aureus (MRSA), Gram-negative bacterium Escherichia coli, and fungal yeast Candida albicans). LC15 was the most powerful broad spectrum antimicrobial fullerenyl photosensitizer (FPS) followed by LC16, and LC14 was least powerful. Killing depended on both fullerene monoadduct concentration and light fluence. UVA was five times more effective than white light for killing, but not for generation of ROS and relative absorption was greater in white spectral region. Bacterial killing was not much inhibited by addition of azide anions and in some cases was potentiated. In the absence of oxygen, microbial photokilling was highly potentiated (up to 5 logs) by the addition of azide anions. We conclude that molecular functional addends that encourage a type I electron-transfer mechanism increase the ability of photoactivated fullerene monoadducts to kill microbial cells. Oxygen-independent photokilling is possible with fullerene monoadducts in the presence of azide anions, probably mediated by azidyl radicals. UVA excitation may kill bacteria partly by an electron-transfer mechanism directly into bacteria as well as by ROS.

Rose bengal (RB) is a halogenated xanthene dye that has been used to mediate antimicrobial photodynamic inactivation for several years. While RB is highly active against Gram-positive bacteria, it is largely inactive in killing Gram-negative bacteria. We have discovered that addition of the nontoxic salt potassium iodide (100 mM) potentiates green light (540-nm)-mediated killing by up to 6 extra logs with the Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa , the Gram-positive bacterium methicillin-resistant Staphylococcus aureus , and the fungal yeast Candida albicans . The mechanism is proposed to be singlet oxygen addition to iodide anion to form peroxyiodide, which decomposes into radicals and, finally, forms hydrogen peroxide and molecular iodine. The effects of these different bactericidal species can be teased apart by comparing the levels of killing achieved in three different scenarios: (i) cells, RB, and KI are mixed together and then illuminated with green light; (ii) cells and RB are centrifuged, and then KI is added and the mixture is illuminated with green light; and (iii) RB and KI are illuminated with green light, and then cells are added after illumination with the light. We also showed that KI could potentiate RB photodynamic therapy in a mouse model of skin abrasions infected with bioluminescent P. aeruginosa .

Seven new lignan glycosides (1-3, 8-10, and 14) and 17 known compounds were isolated from the branches of Alangium kurzii Craib var. laxifolium. Their structures were established by spectroscopic analysis and circular dichroism (CD) and X-ray analysis. The isolated compounds were evaluated for their antibacterial activities against Staphylococcus aureus CI1011, Streptococcus suis CI1608, Salmonella gallinarum CI0912, Enterococcus faecalis CI1304, Aeromonas hydrophila CI1008, Escherichia coli CI151012, Vibrio parahaemolyticus CI150506, Klebsiella pneumoniae CI131216, Pseudomonas aeruginosa CI1011, Staphylococcus epidermidis CI1110, and Streptococcus agalactiae CI1302. Their minimum inhibitory concentrations (MICs) were determined by serial dilution in 96-well culture plates.

Infantile haemangiomas (IHs) are the most common congenital vascular tumours of infancy. Propranolol has been demonstrated to be effective for IHs; however, the factors affecting its therapeutic effect remain unknown. We enrolled 169 infants with IHs of the head and neck region treated with oral propranolol at a dose of 2.0 mg/kg/day. We evaluated the therapeutic responses 6 months after treatment and the end of treatment, which were categorized into four grades. The type and location of the lesions and the infant age at treatment initiation were analysed. The clinical response rate (III + IV) was 91.72% at 6 months after treatment and 97.63% at the end of treatment. The average treatment duration was 9.99 (2–24) months. The group aged 4–6 months exhibited a greater therapeutic response rate (98.48%). The treatment duration was shorter (9.52 months) for mixed-type IHs. Better therapeutic responses were observed for IHs located around the parotid, periorbital, cheek, and neck regions and for multiple IH lesions. Our study indicated that propranolol is effective for IHs affecting the head and neck. The age at treatment initiation and the location of the lesions had a significant effect on the therapeutic response, whereas the lesion type might affect the treatment duration.

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 and harmless visible light to produce reactive oxygen species that kill unwanted cells. However the extreme insolubility and hydrophobicity of pristine CO60, mandated that the cage be functionalized with chemical groups that provided water solubility and biological targeting ability. It has been found that cationic quaternary ammonium groups provide both these features, and this review covers work on the use of cationic fullerenes to mediate destruction of cancer cells and pathogenic microorganisms in vitro and describes the treatment of tumors and microbial infections in mouse models. The design, synthesis, and use of simple pyrrolidinium salts, more complex decacationic chains, and light-harvesting antennae that can be attached to C60, C70 and C84 cages are covered. In the case of bacterial wound infections mice can be saved from certain death by fullerene-mediated PDT.

A series of platinum(II) complexes with reduced amino acid esters Schiff-bases as ligands were prepared as potential anticancer agents and characterized by NMR, IR spectroscopy, elemental analysis and molar conductivity. These compounds were tested for their stability and DNA interaction with salmon sperm DNA by ultraviolet spectrum. The cytotoxicities of these complexes were validated against HL-60, BGC-823, Hela, and HepG2 cell lines by the MTT test. The complexes 5e and 5f exhibited better cytotoxic activity than cisplatin against HepG2 and BGC-823 cell lines, respectively.

We report the synthesis and anticancer photodynamic properties of two new decacationic fullerene (LC14) and red light-harvesting antenna-fullerene conjugated monoadduct (LC15) derivatives. The antenna of LC15 was attached covalently to C60with distance of only3.0 Ǻ to facilitate ultrafast intramolecular photoinduced-electron-transfer (for type-I photochemistry) and photon absorption at longer wavelengths. Because LC15 was hydrophobic we compared formulation in Cremophor EL micelles with direct dilution from dimethylacetamide. LC14 produced more (1)O2 than LC15, while LC15 produced much more HO·than LC14 as measured by specific fluorescent probes. When delivered by DMA, LC14 killed more HeLa cells than LC15 when excited by UVA light, while LC15 killed more cells when excited by white light consistent with the antenna effect. However LC15 was more effective than LC14 when delivered by micelles regardless of the excitation light. Micellar delivery produced earlier apoptosis and damage to the endoplasmic reticulum as well as to lysosomes and mitochondria.This team of authors report the synthesis and the photodynamic properties of two new derivatives for cancer treatment; one is a decacationic fullerene (LC14) and the other is a red light-harvesting antenna-fullerene conjugated monoadduct (LC15) utilizing a HeLa cell model.

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] (LC18), both with a well-defined decacationic quaternary ammonium iodide moiety with ten positive charges per C70 to give water solubility and bacterial binding. We determined the antimicrobial effects against human pathogens, Gram-positive (Staphylococcus aureus) and Gram-negative species (Escherichia coli and Acinetobacter baumannii) when activated by UVA or white light. Results: White light was more effective with LC17, while UVA light was more effective with LC18. Both compounds were effective in a mouse model of Gram-negative third-degree burn infections determined by bioluminescence imaging. Discussion & conclusion: We propose that the attachment of an additional deca(tertiary-ethylenylamino)malonate arm to C70 allowed the moiety to act as a potent electron donor and increased the generation yield of hydroxyl radicals under UVA illumination. Original submitted 13 June 2012; Revised submitted 10 January 2013; Published online 5 June 2013

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 the efficacy of blue light (415±10 nm) therapy for eliminating CA-MRSA infections in skin abrasions of mice. Methods: The susceptibilities of a CA-MRSA strain (USA300LAC) and human keratinocytes (HaCaT) to blue light inactivation were compared by in vitro culture studies. A mouse model of skin abrasion infection was developed using bioluminescent USA300LAC::lux. Blue light was delivered to the infected mouse skin abrasions at 30 min (acute) and 24 h (established) after the bacterial inoculation. Bioluminescence imaging was used to monitor in real time the extent of infection in mice. Results: USA300LAC was much more susceptible to blue light inactivation than HaCaT cells (p=0.038). Approximately 4.75-log10 bacterial inactivation was achieved after 170 J/cm2 blue light had been delivered, but only 0.29 log10 loss of viability in HaCaT cells was observed. Transmission electron microscopy imaging of USA300LAC cells exposed to blue light exhibited disruption of the cytoplasmic content, disruption of cell walls, and cell debris. In vivo studies showed that blue light rapidly reduced the bacterial burden in both acute and established CA-MRSA infections. More than 2-log10 reduction of bacterial luminescence in the mouse skin abrasions was achieved when 41.4 (day 0) and 108 J/cm2 (day 1) blue light had been delivered. Bacterial regrowth was observed in the mouse wounds at 24 h after the blue light therapy. Conclusions: There exists a therapeutic window of blue light for bacterial infections where bacteria are selectively inactivated by blue light while host tissue cells are preserved. Blue light therapy has the potential to rapidly reduce the bacterial load in SSTI.

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 mitochondrial dysfunction and cell death. Excitotoxicity contributes to brain damage after stroke, traumatic brain injury, and neurodegenerative diseases, and is also involved in spinal cord injury. We tested whether low level laser (light) therapy (LLLT) at 810 nm could protect primary murine cultured cortical neurons against excitotoxicity in vitro produced by addition of glutamate, NMDA or kainate. Although the prevention of cell death was modest but significant, LLLT (3 J/cm(2) delivered at 25 mW/cm(2) over 2 min) gave highly significant benefits in increasing ATP, raising mitochondrial membrane potential, reducing intracellular calcium concentrations, reducing oxidative stress and reducing nitric oxide. The action of LLLT in abrogating excitotoxicity may play a role in explaining its beneficial effects in diverse central nervous system pathologies.