Multifunctional nanoplatform based on g-C3N4, loaded with MnO2 and CuS nanoparticals for oxygen self-generation photodynamic/photothermal synergistic therapy

Photodynamic therapy (PDT) and photothermal therapy (PTT) are both promising therapeutic approaches for cancer. Unfortunately, the anticancer efficiency of PDT is restricted by the hypoxic tumor microenvironment and the performance of the photosensitizer (PS) while the efficiency of PTT is limited by the penetration depth of NIR light, making it difficult to further improve the efficiency of the treatment. In this paper, we strategically proposed a multifunctional nano-platform based on g-C₃N₄ and loaded with CuS and MnO₂ nanoparticals. Interestingly, the obtained F127@CNs-CuS/MnO₂ nano-platform with high singlet oxygen quantum yield and excellent photothermal performance were used in synergistic PTT and PDT therapy to cope with the limitation of single mode cancer treatment under irradiation and has greatly improved the treatment effect. Additionally, MnO₂ nanoparticles loaded on the CNs surface could not only generate oxygen to ameliorate hypoxia in the tumor environment by reacting with H₂O₂ in tumor cells, but also react with the over-expressed reduced glutathione (GSH) in cancer cells to further improve the synergistic therapeutic effect. In the in vitro hepatocarcinoma cell inactivation experiment, the maximum cell inactivation efficiency of the PDT, PTT and PDT/PTT synergistic treatment group reached at 65% (F127@CNs-MnO₂), 69.2% (CNs-MnO₂) and 88.6% (F127@CNs-MnO₂) respectively, which means that the F127@CNs-CuS/MnO₂-mediated PTT/PDT synergy anticancer treatment was more effective than single mode therapy. In summary, the innovative multifunctional nanoplatform F127@CNs-CuS/MnO₂ used for synergistic PTT and PDT treatment has greatly improved the inactivation efficiency of cancer cells and has provided a new scheme for the treatment of hypoxic tumors.     

Photo-activated elimination of Aggregatibacter actinomycetemcomitans in planktonic culture: Comparison of photodynamic therapy versus photothermal therapy method

BackgroundPeriodontal pathogens are the main factors responsible for periodontal diseases and considering the limitations of conventional mechanical debridement, new treatment approaches are under investigation. This study was designed to evaluate and compare the antibacterial effects of two different systems of photodynamic and photothermal therapy on Aggregatibacter actinomycetemcomitans as the main pathogen involved in aggressive Periodontitis.MethodsCultures of Aggregatibacter actinomycetemcomitans were exposed to 662 nm laser in presence of Radachlorin^® photosensitizer (photodynamic group) or 810 nm laser in presence of EmunDo^® photosensitizer (photothermal group), then bacterial suspension of each well in the study groups were diluted and subcultured on the surface of Muller-Hinton agar plates. subsequently the number of colony forming units per milliliter of the wells were determined and checked by analysis of variance and Tukey test (p < 0.05).ResultsAggregatibacter actinomycetemcomitans suspensions showed significant reduction in both groups of photodynamic and photothermal therapy with no priority.ConclusionBased on the results of this study, photodynamic and photothermal therapy can be proposed as a new promising approaches for bacterial elimination in periodontal diseases.     

Chlorin e6 conjugated copper sulfide nanoparticles for photodynamic combined photothermal therapy

The photo-based therapeutic approaches have attracted tremendous attention in recent years especially in treatment and management of tumors. Photodynamic and photothermal are two major therapeutic modalities which are being applied in clinical therapy. The development of nanomaterials for photodynamic combined with photothermal therapy has gained significant attention for its treatment efficacy. In the present study, we designed chlorin e6 (Ce6) conjugated copper sulfide (CuS) nanoparticles (CuS-Ce6 NPs) through amine functionalization and the synthesized nanoparticles act as a dual-model agent for photodynamic therapy and photothermal therapy. CuS-Ce6 NPs showed enhanced photodynamic effect through generation of singlet oxygen upon 670 nm laser illumination. The same nanoparticles exerted thermal response under an 808 nm laser at 2 W/cm². The fabricated nanoparticles did not show any cytotoxic effect toward breast cancer cells in the absence of light. In vitro cell viability assay showed a potent cytotoxicity in photothermal and photodynamic treatment. Rather than singular treatment, the photodynamic combined photothermal treatment showed an enhanced cytotoxic effect on treated cells. In addition, the CuS-Ce6 NPs exert a photoacoustic signal for non-invasive imaging of treated cells in tissue-mimicking phantom. In conclusion the CuS-Ce6 NPs act as multimodal agent for photo based imaging and therapy.     

Pemphigus vulgaris induced by 5-aminolaevulinic acid-based photodynamic therapy

Pemphigus vulgaris (PV) is an autoimmune disorder resulting from the interaction between autoantibodies and desmoglein. Here, we report a case of PV developed after 5-aminolaevulinic acid-based photodynamic therapy (ALA-PDT). The harmful and deleterious effects of UV radiation on the onset, during course, and perpetuation of PV have been observed for decades. Correlation between reactive oxygen species (ROS) and PV have also been reported. Oxidative proteins, which are modified by ROS, and subsequent production of antibodies by immune system seem to be responsible for PV developed following ALA-PDT. We emphasize that ALA-PDT should be added to the list of possible factors triggering PV and this condition should be considered if blistering arises following ALA-PDT.     

Palmatine hydrochloride mediated photodynamic inactivation of breast cancer MCF-7 cells: Effectiveness and mechanism of action

Breast cancer is one of the commonest malignant tumors threatening to women. The present study aims to investigate the effect of photodynamic action of palmatine hydrochloride (PaH), a naturally occurring photosensitizer isolated from traditional Chinese medicine (TCM), on apoptosis of breast cancer cells. Firstly, cellular uptake of PaH in MCF-7 cells was measured and the cytotoxicity of PaH itself on breast cancer MCF-7 cells was estimated using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Subcellular localization of PaH in MCF-7 cells was observed using confocal laser scanning microscopy (CLSM). For photodynamic treatment, MCF-7 cells were incubated with PaH and then irradiated by visible light (470 nm) from a LED light source. Photocytotoxicity was investigated 24 h after photodynamic treatment using MTT assay. Cell apoptosis was analyzed 18 h after photodynamic treatment using flow cytometry with Annexin V/PI staining. Nuclear was stained using Hoechst 33342 and observed under a fluorescence microscope. Intracellular production of reactive oxygen species (ROS) was studied by measuring the fluorescence of 2, 7-dichlorofluorescein (DCF) using a flow cytometry. Results showed that PaH treatment alone had no or minimum cytotoxicity to MCF-7 cells after incubation for 24 h in the dark. After incubation for 40 min, the cellular uptake of PaH reached to the maximum, and PaH mainly located in mitochondria and endoplasmic reticulum of MCF-7 cells. Photodynamic treatment of PaH demonstrated a significant photocytotoxicity on MCF-7 cells, induced remarkable cell apoptosis and significantly increased intracellular ROS level. Our findings demonstrated that PaH as a naturally occurring photosensitizer induced cell apoptosis and significantly killed MCF-7 cells.     

Singlet oxygen production by combining erythrosine and halogen light for photodynamic inactivation of Streptococcus mutans

BackgroundPhotodynamic inactivation of microorganisms is based on a photosensitizing substance which, in the presence of light and molecular oxygen, produces singlet oxygen, a toxic agent to microorganisms and tumor cells. This study aimed to evaluate singlet oxygen quantum yield of erythrosine solutions illuminated with a halogen light source in comparison to a LED array (control), and the photodynamic effect of erythrosine dye in association with the halogen light source on Streptococcus mutans.MethodsSinglet oxygen quantum yield of erythrosine solutions was quantified using uric acid as a chemical-probe in an aqueous solution. The in vitro effect of the photodynamic antimicrobial activity of erythrosine in association with the halogen photopolimerizing light on Streptococcus mutans (UA 159) was assessed during one minute. Bacterial cultures treated with erythrosine alone served as negative control.ResultsSinglet oxygen with 24% and 2.8% degradation of uric acid in one minute and a quantum yield of 0.59 and 0.63 was obtained for the erythrosine samples illuminated with the halogen light and the LED array, respectively. The bacterial cultures with erythrosine illuminated with the halogen light presented a decreased number of CFU mL⁻¹ in comparison with the negative control, with minimal inhibitory concentrations between 0.312 and 0.156 mg mL⁻¹.ConclusionsThe photodynamic response of erythrosine induced by the halogen light was capable of killing S. mutans. Clinical trials should be conducted to better ascertain the use of erythrosine in association with halogen light source for the treatment of dental caries.     

In vitro evaluation of ruthenium complexes for photodynamic therapy

BackgroundPhotodynamic therapy (PDT) is a promising anti-tumor treatment strategy. Photosensitizer is one of the most important components of PDT. In this work, the anticancer activities of PDT mediated by six new ruthenium porphyrin complexes were screened. The mechanisms of the most efficacious candidate were investigated.MethodsPhotocytotoxicity of the six porphyrins was tested. The most promising complex, Rup-03, was further investigated using Geimsa staining, which indirectly detects reactive oxygen species (ROS) and subcellular localization. Mitochondrial membrane potential (MMP), cell apoptosis, DNA fragmentation, c-Myc gene expression, and telomerase activities were also assayed.ResultsRup-03 and Rup-04 had the lowest IC₅₀ values. Rup-03 had an IC₅₀ value of 29.5 ± 2.3 μM in HepG2 cells and 59.0 ± 6.1 μM in RAW264.7 cells, while Rup-04 had an IC₅₀ value of 40.0 ± 3.8 μM in SGC-7901 cells. The complexes also induced cellular morphological changes and impaired cellular ability to scavenge ROS, and accumulated preferentially in mitochondria and endoplasmic reticulum. Rup-03 reduced MMP levels, induced apoptosis, and repressed both c-Myc mRNA expression and telomerase activity in HepG2 cells.ConclusionsAmong six candidates, Rup-03-mediated PDT is most effective against HepG2 and RAW264.7, with a similar efficacy as that of Rup-04-mediated PDT against SGC-7901 cells. Repression of ROS scavenging activities and c-Myc expression, which mediated DNA damage-induced cell apoptosis and repression of telomerase activity, respectively, were found to be involved in the anticancer mechanisms of Rup-03.     

竹红菌素光动力学作用中细胞的凋亡和坏死

竹红菌素由于其显著的光诱导抗肿瘤和抗病毒的作用而受到广泛的关注。竹红菌素已经成功地应用于光动力学治疗皮肤等疾病。光动力学作用导致靶细胞损伤的机制中坏死和凋亡起重要作用。笔者总结了文献中一系列结构修饰的竹红菌素对产生活性氧物质(1O2,O2-.OH.)和对提高光动力学疗效的影响,还总结了竹红菌素光动力学过程中结构修饰对细胞凋亡和坏死的影响。     

In vitro assessment of anti-tumorigenic mechanisms and efficacy of NanoALA,a nanoformulation of aminolevulic acid designed for photodynamic therapy of cancer

BackgroundThe development of nanocarriers is an important approach to increase the bioavailability of hydrophilic drugs in target cells. In this work, we evaluated the anti-tumorigenic mechanisms and efficacy of NanoALA, a novel nanoformulation of aminolevulic acid (ALA) based on poly(lactide-co-glycolide) (PLGA) nanocapsules designed for anticancer photodynamic therapy (PDT).MethodsFor this purpose, physicochemical characterization, prodrug incorporation kinetics, biocompatibility and photocytotoxicity tests, analysis of the cell death type and mitochondrial function, measurement of the intracellular reactive oxygen species production and DNA fragmentation were performed in murine mammary carcinoma (4T1) cells.ResultsNanoALA formulation, stable over a period of 90 days following synthesis, presented hydrodynamic diameter of 220 ± 8.7 nm, zeta potential of −30.6 mV and low value of polydispersity index (0.28). The biological assays indicated that the nanostructured product promotes greater ALA uptake by 4T1 cells and consequently more cytotoxicity in the PDT process. For the first time in the scientific literature, there is a therapeutic efficacy report of approximately 80%, after only 1 h of incubation with 100 μg mL⁻¹ prodrug (0.6 mM ALA equivalent). The mitochondria are probably the initial target of treatment, culminating in energy metabolism disorders and cell death by apoptosis.ConclusionsNanoALA emerges as a promising strategy for anticancer PDT. Besides being effective against a highly aggressive tumor cell line, the treatment may be economically advantageous because it allows a reduction in the dose and frequency of application compared to free ALA.     

Chromatin‐ and temperature‐dependent modulation of radiation‐induced double‐strand breaks

Purpose: To investigate the influence of chromatin organization and scavenging capacity in relation to irradiation temperature on the induction of double‐strand breaks (DSB) in structures derived from human diploid fibroblasts.

Materials and methods: Agarose plugs with different chromatin structures (intact cells±wortmannin, permeabilized cells with condensed chromatin, nucleoids and DNA) were prepared and irradiated with X‐rays at 2 or 37°C and lysed using two different lysis protocols (new ice‐cold lysis or standard lysis at 37°C). Induction of DSB was determined by constant‐field gel electrophoresis.

Results: The dose‐modifying factor (DMF_temp) for irradiation at 37 compared with 2°C was 0.92 in intact cells (i.e. more DSB induced at 2°C), but gradually increased to 1.5 in permeabilized cells, 2.2 in nucleoids and 2.6 in naked DNA, suggesting a role of chromatin organization for temperature modulation of DNA damage. In addition, DMF_temp was influenced by the presence of 0.1?M DMSO or 30?mM glutathione, but not by post‐irradiation temperature.

Conclusion: The protective effect of low temperature was correlated to the indirect effects of ionizing radiation and was not dependent on post‐irradiation temperature. Reasons for a dose modifying factor <1 in intact cells are discussed.     

Curcumin-gold-polyethylene glycol nanoparticles as a nanosensitizer for photothermal and sonodynamic therapies: In vitro and animal model studies

Photothermal and ultrasound therapies are novel non-invasive strategies for tumor treatment which are equipped with a photosensitizer and sonosensitizer subsequent activation by laser irradiation and ultrasound exposure. In this study, curcumin-gold-polyethylene glycol nanoparticles (Cur-Au NPs-PEG) were synthesized, and the dual role in photothermal (PTT) and sonodynamic (SDT) therapies of melanoma cancer was evaluated. The toxicity effect of Cur-Au NPs-PEG against a mouse malignant melanoma cell line C540 (B16/F10) was firstly inspected in vitro. Cur-Au NPs-PEG provided a hyperthermal microenvironment and generated reactive oxygen species upon PTT and STD, respectively, with representing synergism effects. Studies in vivo in a tumor-bearing animal also demonstrate the superiority of PTT and SDT in destroying melanoma tumor.     

益肺活血颗粒对缺氧大鼠肺动脉平滑肌细胞内低氧诱导因子-1α和活性氧的影响

目的观察益肺活血颗粒对低氧培养大鼠肺动脉平滑肌细胞（pulmonaryarterysmoothmusclecells,PASMCs）内低氧诱导因子-1αhypoxiainduciblefactor一1alpha,HIF-1α和活性氧（Feacriveoxygenspecies,ROS）的影响。方法采用血清药理学方法制备不同浓度的益肺活血颗粒（yifeihuoxuegranule,YFHXG）含药血清,采用组织块贴壁法原代培养大鼠PASMCs,取对数生长期PASMCs随机分为常氧组、缺氧组、缺氧＋YFHXG组（16．5、3．3、0．66g／kg）。用噻唑蓝比色法测定各组PASMCs的增殖效应,免疫组化法测定细胞内HIF-1α蛋白的表达,激光共聚焦显微镜测定细胞内ROS的含量。结果与常氧组相比,缺氧组PASMCs增殖明显活跃,HIF-1α蛋白表达及ROS含量增加;与缺氧组相比,缺氧＋YFHXG高、中浓度组大鼠PASMCs的生长明显受抑制,而且HIF-1α蛋白表达及ROS含量降低。结论缺氧可以直接刺激PASMCs的增殖。YFHXG可以显著抑制低氧对大鼠PASMCs的促增殖作用,其机制可能是通过降低细胞内HIF-1α蛋白表达及ROS的水平来实现的。     

Lutetium(III) acetate phthalocyanines for photodynamic therapy applications: Synthesis and photophysicochemical properties

BackgroundThe development of new water-soluble photosensitizers for photodynamic therapy (PDT) applications is a very active research topic. Efforts have been made to obtain the far-red absorbing phthalocyanine complexes with molecular design that facilitates the uptake and selectivity for a high PDT efficiency.MethodsThe monomolecular lutetium(III) acetate phthalocyanines (LuPcs) substituted with methylpyridyloxy groups at non-peripheral (5) and peripheral (6) positions were synthesized by following the modification of the well-known synthetical routes. The photo-physicochemical properties of the both quaternized LuPcs were evaluated by the steady-state and time-resolved spectroscopy. The photochemical technique was applied to study the generation of the singlet oxygen.ResultsTwo water-soluble and cationic LuPcs were synthesized and chemically characterized. The photo-physicochemical properties of absorption (675 and 685 nm) and the red shifted fluorescence (704 and 721 nm) as well as the fluorescence lifetimes (2.24 and 3.27 ns) were studied. The promising values of singlet oxygen quantum yields (0.32 for 5 and 0.35 for 6) were determined.ConclusionsLutetium(III) acetate phthalocyanine complexes were synthesized and evaluated with physicochemical properties suitable for future photodynamic therapy applications.     

Quality of life following photodynamic therapy for head and neck pathologies: An exploratory study

IntroductionHealthcare related quality of life (QoL) is defined as the impact one's level of health and wellbeing has on a number of domains, including physical, mental, spiritual and social functions. Photodynamic therapy (PDT), a cancer treatment modality, is increasingly used to treat or palliate head and neck pathologies. Due to the complex nature of this area of the body, both the pathology and the treatment of it can severely affect the quality of life. Thus far, no questionnaire has been developed which focuses on quality-of-life post-PDT of head and neck pathologies.Patients and methodsWe have developed the University College London Quality of Life Questionnaire for Patients undergoing PDT in the Head and Neck, using meta-tetra(hydroxyphenyl)chlorin (mTHPC) as the photosensitiser. This was modified from the University of Washington quality of life (UW-QOL) questionnaire. Thirty-eight patients who received mTHPC-PDT for various head and neck pathologies completed the questionnaire, with a mean follow-up of 56 days.ResultsAll patients reported improved QoL following mTHPC-PDT. The main problem that was reported was post-PDT pain, which is a common side effect. Visual symptoms, breathing, speaking and swallowing problems improved significantly in the 4th week following treatment and significant improvement in activities of daily living, social life, mood and anxiety were reported in the subsequent weeks.ConclusionsmTHPC-PDT confers improvement in QoL score in selected head and neck cancer patients with figures comparable to other treatment modalities. This exploratory study demonstrated patterns of QoL outcome. Further work needs to be done for survey validation and inclusion of a larger cohort which will allow optimal sub-group analysis and help guide further interventions.     

Chronic fatigue and immune deficiency syndrome (CFIDS), cellular metabolism,and ionizing radiation: a review of contemporary scientific literature and suggested directions for future research

Purpose: To investigate biochemical pathways known to be involved in radiation response and in CFIDS to determine if there might be common underlying mechanisms leading to symptoms experienced by those accidentally or deliberately exposed to radiation and those suffering from CFIDS. If such a link was established to suggest testable hypotheses to investigate the mechanisms with the aim of identifying new therapeutic targets.

Conclusions: Evidence for involvement of the alpha-synuclein, cytochrome c oxidase, αB-crystallin, RNase L, and lactate dehydrogenase/STAT1 pathways is strong and suggests a common underlying mechanism involving mitochondrial dysfunction mediated by ROS and disruption of ATP production. The downstream effect of this is compromised energy production. Testable hypotheses are suggested to investigate the involvement of these pathways further.     

Reactive oxygen species mediates 50-Hz magnetic field-induced EGF receptor clustering via acid sphingomyelinase activation

Purpose: Exposure to extremely low frequency electromagnetic fields (ELF-EMFs) could elicit biological effects including carcinogenesis. However, the detailed mechanisms by which these ELF-EMFs interact with biological system are currently unclear. Previously, we found that a 50-Hz magnetic field (MF) exposure could induce epidermal growth factor receptor (EGFR) clustering and phosphorylation on cell membranes. In the present experiment, the possible roles of reactive oxygen species (ROS) in MF-induced EGFR clustering were investigated.

Materials and methods: Human amnion epithelial (FL) cells were exposed to a 50-Hz MF with or without N-acetyl-l-cysteine (NAC) or pyrrolidine dithiocarbamate (PDTC). EGFR clustering on cellular membrane surface was analyzed using confocal microscopy after indirect immunofluorescence staining. The intracellular ROS level and acid sphingomyelinase (ASMase) activity were detected using an ROS assay kit and an Amplex^® Red Sphingomyelinase Assay Kit, respectively.

Results: Results showed that exposure of FL cells to a 50-Hz MF at 0.4?mT for 15?min significantly enhanced the ROS level, induced EGFR clustering and increased ASMase activity. However, pretreatment with NAC or PDTC, the scavenger of ROS, not only counteracted the effects of a 50-Hz MF on ROS level and AMS activity, but also inhibited the EGFR clustering induced by MF exposure.

Conclusions: The present and previous data suggest that ROS mediates the MF-induced EGFR clustering via ASMase activation.     

Radiation hormesis: Autophagy and other cellular mechanisms

Abstract

Purpose: To review the cellular mechanisms of hormetic effects induced by low dose and low dose rate ionising radiation in model systems, and to call attention to the possible role of autophagy in some hormetic effects.

Results and conclusions: Very low radiation doses stimulate cell proliferation by changing the equilibrium between the phosphorylated and dephosphorylated forms of growth factor receptors. Radioadaptation is induced by various weak stress stimuli and depends on signalling events that ultimately decrease the molecular damage expression at the cellular level upon subsequent exposure to a moderate radiation dose. Ageing and cancer result from oxidative damage under oxidative stress conditions; nevertheless, ROS are also prominent inducers of autophagy, a cellular process that has been shown to be related both to ageing retardation and cancer prevention. A balance between the signalling functions and damaging effects of ROS seems to be the most important factor that decides the fate of the mammalian cell when under oxidative stress conditions, after exposure to ionising radiation. Not enough is yet known on the pre-requirements for maintaining such a balance. Given the present stage of investigation into radiation hormesis, the application of the conclusions from experiments on model systems to the radiation protection regulations would not be justified.