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Scientific Reports Jun 2015High power lasers are used extensively in medicine while lower power applications are popular for optical imaging, optogenetics, skin rejuvenation and a therapeutic...
High power lasers are used extensively in medicine while lower power applications are popular for optical imaging, optogenetics, skin rejuvenation and a therapeutic modality termed photobiomodulation (PBM). This study addresses the therapeutic dose limits, biological safety and molecular pathway of near-infrared (NIR) laser phototoxicity. Increased erythema and tissue damage were noted in mice skin and cytotoxicity in cell cultures at phototoxic laser doses involving generation of reactive oxygen species (ROS) coupled with a rise in surface temperature (>45 °C). NIR laser phototoxicity results from Activating Transcription Factor-4 (ATF-4) mediated endoplasmic reticulum stress and autophagy. Neutralizations of heat or ROS and overexpressing ATF-4 were noted to rescue NIR laser phototoxicity. Further, NIR laser mediated phototoxicity was noted to be non-genotoxic and non-mutagenic. This study outlines the mechanism of NIR laser phototoxicity and the utility of monitoring surface temperature and ATF4 expression as potential biomarkers to develop safe and effective clinical applications.
Topics: Activating Transcription Factor 4; Animals; Apoptosis; Cell Line; DNA Damage; Endoplasmic Reticulum Stress; Hot Temperature; Humans; Lasers; Mice; Reactive Oxygen Species; Reproducibility of Results; Signal Transduction; Skin; Skin Temperature
PubMed: 26030745
DOI: 10.1038/srep10581 -
Scientific Reports Oct 2019Light-activated theranostics offer promising opportunities for disease diagnosis, image-guided surgery, and site-specific personalized therapy. However, current...
Light-activated theranostics offer promising opportunities for disease diagnosis, image-guided surgery, and site-specific personalized therapy. However, current fluorescent dyes are limited by low brightness, high cytotoxicity, poor tissue penetration, and unwanted side effects. To overcome these limitations, we demonstrate a platform for optoelectronic tuning, which allows independent control of the optical properties from the electronic properties of fluorescent organic salts. This is achieved through cation-anion pairing of organic salts that can modulate the frontier molecular orbital without impacting the bandgap. Optoelectronic tuning enables decoupled control over the cytotoxicity and phototoxicity of fluorescent organic salts by selective generation of mitochondrial reactive oxygen species that control cell viability. We show that through counterion pairing, organic salt nanoparticles can be tuned to be either nontoxic for enhanced imaging, or phototoxic for improved photodynamic therapy.
Topics: A549 Cells; Animals; Anions; Cations; Cell Line, Tumor; Cell Survival; Dermatitis, Phototoxic; Female; Fluorescent Dyes; Humans; Mice; Nanoparticles; Neoplasms, Experimental; Optical Imaging; Organic Chemicals; Photochemotherapy; Photosensitizing Agents; Reactive Oxygen Species; Salts; Theranostic Nanomedicine; Transplantation, Heterologous
PubMed: 31653966
DOI: 10.1038/s41598-019-51593-z -
Journal of Biomedical Optics Sep 2012Voltage-sensitive fluorescent dyes have become a major tool in cardiac and neuro-electrophysiology. Achieving high signal-to-noise ratios requires increased illumination... (Comparative Study)
Comparative Study
Voltage-sensitive fluorescent dyes have become a major tool in cardiac and neuro-electrophysiology. Achieving high signal-to-noise ratios requires increased illumination intensities, which may cause photobleaching and phototoxicity. The optimal range of illumination intensities varies for different dyes and must be evaluated individually. We evaluate two dyes: di-4-ANBDQBS (excitation 660 nm) and di-4-ANEPPS (excitation 532 nm) in the guinea pig heart. The light intensity varies from 0.1 to 5 mW/mm2, with the upper limit at 5 to 10 times above values reported in the literature. The duration of illumination was 60 s, which in guinea pigs corresponds to 300 beats at a normal heart rate. Within the identified duration and intensity range, neither dye shows significant photobleaching or detectable phototoxic effects. However, light absorption at higher intensities causes noticeable tissue heating, which affects the electrophysiological parameters. The most pronounced effect is a shortening of the action potential duration, which, in the case of 532-nm excitation, can reach ∼30%. At 660-nm excitation, the effect is ∼10%. These findings may have important implications for the design of optical mapping protocols in biomedical applications.
Topics: 2-Naphthylamine; Action Potentials; Animals; Body Surface Potential Mapping; Fluorescent Dyes; Heart Conduction System; Pyridinium Compounds; Quinolinium Compounds; Reproducibility of Results; Sensitivity and Specificity; Swine; Voltage-Sensitive Dye Imaging
PubMed: 23085908
DOI: 10.1117/1.JBO.17.9.096007 -
JAAD Case Reports Apr 2023
PubMed: 36936864
DOI: 10.1016/j.jdcr.2023.01.021 -
Cell Proliferation Apr 2013Our interest continues in discovering phytocomplexes from medicinal plants with phototoxic activity against human melanoma cells; thus the aim of the present study was...
OBJECTIVES
Our interest continues in discovering phytocomplexes from medicinal plants with phototoxic activity against human melanoma cells; thus the aim of the present study was to assess antioxidant, anti-inflammatory and phototoxic activity of Hypericum perforatum L. subsp. perforatum, and relate these properties to the plant's chemical composition.
MATERIALS AND METHODS
Components of H. perforatum subsp. perforatum were extracted by hydroalcoholic solution and chemical profiles of preparations (HyTE-3) performed by HPTLC. Linoleic acid peroxidation and DPPH tests were used to assess antioxidant activity, while MTT assay allowed evaluation of anti-proliferative activity with respect to A375 human melanoma cells after irradiation with UVA dose, 1.8 J/cm(2) . Inhibition of nitric oxide production of macrophages was also investigated.
RESULTS
HyTE-3 indicated better antioxidant activity with β-carotene bleaching test in comparison to DPPH assay (IC50 = 0.89 μg/ml); significant phototoxicity in A375 cells at 78 μg/ml concentration resulted in cell destruction of 50%. HyTE-3 caused significant dose-related inhibition of nitric oxide production in murine monocytic macrophage cell line RAW 264.7 with IC50 value of 342 μg/ml.
CONCLUSIONS
The H. perforatum subsp. perforatum-derived product was able to suppress proliferation of human malignant melanoma A375 cells; extract together with UVA irradiation enhanced phototoxicity. This biological activity of antioxidant effects was combined with inhibition of nitric oxide production.
Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Antineoplastic Agents, Phytogenic; Cell Line, Tumor; Cell Proliferation; Free Radical Scavengers; Free Radicals; Humans; Hypericum; Inhibitory Concentration 50; Macrophages; Melanoma; Mice; Nitric Oxide; Phenols; Photosensitizing Agents; Plant Components, Aerial; Plant Extracts; Ultraviolet Rays; beta Carotene
PubMed: 23510474
DOI: 10.1111/cpr.12020 -
Journal of the American Chemical Society Aug 2021Fluorescent voltage indicators are an attractive alternative for studying the electrical activity of excitable cells; however, the development of indicators that are...
Fluorescent voltage indicators are an attractive alternative for studying the electrical activity of excitable cells; however, the development of indicators that are both highly sensitive and low in toxicity over long-term experiments remains a challenge. Previously, we reported a fluorene-based voltage-sensitive fluorophore that exhibits much lower phototoxicity than previous voltage indicators in cardiomyocyte monolayers, but suffers from low sensitivity to membrane potential changes. Here, we report that the addition of a single vinyl spacer in the fluorene molecular wire scaffold improves the voltage sensitivity 1.5- to 3.5-fold over fluorene-based voltage probes. Furthermore, we demonstrate the improved ability of the new vinyl-fluorene VoltageFluors to monitor action potential kinetics in both mammalian neurons and human-induced pluripotent stem cell-derived cardiomyocytes. Addition of the vinyl spacer between the aniline donor and fluorene monomer results in indicators that are significantly less phototoxic in cardiomyocyte monolayers. These results demonstrate how structural modification to the voltage sensing domain have a large effect on improving the overall properties of molecular wire-based voltage indicators.
Topics: Fluorenes; Fluorescent Dyes; HEK293 Cells; Humans; Molecular Structure; Myocytes, Cardiac; Neurons; Photochemical Processes; Vinyl Compounds
PubMed: 34323478
DOI: 10.1021/jacs.1c04543 -
International Journal of Nanomedicine 2019Photodynamic therapy (PDT), a clinical anticancer therapeutic modality, has a long history in clinical cancer treatments since the 1970s. However, PDT has not been...
BACKGROUND
Photodynamic therapy (PDT), a clinical anticancer therapeutic modality, has a long history in clinical cancer treatments since the 1970s. However, PDT has not been widely used largely because of metabolic problems and off-target phototoxicities of the current clinical photosensitizers.
PURPOSE
The objective of the study is to develop a high-efficiency and high-specificity carrier to precisely deliver photosensitizers to tumor sites, aiming at addressing metabolic problems, as well as the systemic damages current clinical photosensitizers are known to cause.
METHODS
We synthesized a polydopamine (PDA)-based carrier with the modification of folic acid (FA), which is to target the overexpressed folate receptors on tumor surfaces. We used this carrier to load a cationic phthalocyanine-type photosensitizer (Pc) and generated a PDA-FA-Pc nanomedicine. We determined the antitumor effects and the specificity to tumor cell lines in vitro. In addition, we established human cancer-xenografted mice models to evaluate the tumor-targeting property and anticancer efficacies in vivo.
RESULTS
Our PDA-FA-Pc nanomedicine demonstrated a high stability in normal physiological conditions, however, could specifically release photosensitizers in acidic conditions, eg, tumor microenvironment and lysosomes in cancer cells. Additionally, PDA-FA-Pc nanomedicine demonstrated a much higher cellular uptake and phototoxicity in cancer cell lines than in healthy cell lines. Moreover, the in vivo imaging data indicated excellent tumor-targeting properties of PDA-FA-Pc nanomedicine in human cancer-xenografted mice. Lastly, PDA-FA-Pc nanomedicine was found to significantly suppress tumor growth within two human cancer-xenografted mice models.
CONCLUSION
Our current study not only demonstrates PDA-FA-Pc nanomedicine as a highly potent and specific anticancer agent, but also suggests a strategy to address the metabolic and specificity problems of clinical photosensitizers.
Topics: Animals; Cell Line, Tumor; Drug Carriers; Drug Stability; Female; Folic Acid; HeLa Cells; Humans; Indoles; Isoindoles; MCF-7 Cells; Mice; Nanomedicine; Nanoparticles; Organometallic Compounds; Photochemotherapy; Photosensitizing Agents; Polymers; Xenograft Model Antitumor Assays; Zinc Compounds
PubMed: 31692522
DOI: 10.2147/IJN.S216194 -
Journal of the American Board of Family... 2021Phytophotodermatitis is a cutaneous reaction caused by direct contact with phototoxic agents and subsequent sunlight exposure. Furocoumarins and psoralens are 2...
Phytophotodermatitis is a cutaneous reaction caused by direct contact with phototoxic agents and subsequent sunlight exposure. Furocoumarins and psoralens are 2 phototoxic agents that can cause this reaction, and these organic chemical compounds are found in many plant species consumed by humans. Following contact exposure to such foods and ultraviolet radiation exposure via direct sunlight, phytophotodermatitis can occur. Due to the etiology of these rashes relating closely to the outdoor consumption of margaritas, the rash may be known by patients as "margarita burn." There is a classically described sequence of rash progression: erythematous macules or patches, which later become vesicles and seem similar to second-degree burns, followed by an asymptomatic hyperpigmentation. This case presents a 26-year-old female diagnosed with phytophotodermatitis following use of citrus fruits for margaritas while outdoors in direct sunlight. The diagnosis of phytophotodermatitis is often made clinically but can be complicated due to its similarity in appearance to many other common cutaneous reactions. In this patient, the differential diagnosis included solar erythema, contact dermatitis (type IV hypersensitivity reaction), polymorphic light eruption, or drug-related photosensitivity. Careful history taking is essential in not only narrowing down the differential diagnosis but also in avoiding unnecessary tests or ineffective treatments.
Topics: Adult; Burns; Dermatitis, Phototoxic; Female; Furocoumarins; Humans; Sunlight; Ultraviolet Rays
PubMed: 33833009
DOI: 10.3122/jabfm.2021.02.200382 -
Dermatology Online Journal Feb 2018Phytophotodermatitis results when skin is exposed to ultraviolet light after previous contact with a phototoxic compound. Wild parsnip (Pastinia sativa), a member of the...
Phytophotodermatitis results when skin is exposed to ultraviolet light after previous contact with a phototoxic compound. Wild parsnip (Pastinia sativa), a member of the Umbelliferae family, is an invasive plant species introduced to North America as a root vegetable. Although cultivated less commonly today, the plant is increasingly found growing wild in prairies and roadsides. The stems and leaves contain furocoumarins, which upon activation by UV light interact with oxygen. Resultant reactive oxygen species induce tissue damage manifesting initially as blistering and later as hyperpigmentation. We report the case of a woman who developed phytophoto-dermatitis after encountering wild parsnip on a midwestern prairie.
Topics: Dermatitis, Phototoxic; Female; Humans; Pastinaca; Young Adult
PubMed: 29630166
DOI: No ID Found -
Canadian Family Physician Medecin de... Mar 1998
Topics: Adult; Dermatitis, Occupational; Dermatitis, Phototoxic; Diagnosis, Differential; Female; Fruit; Furocoumarins; Humans; Photosensitizing Agents; Plants, Toxic; Vegetables
PubMed: 9559189
DOI: No ID Found