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15 pages, 3453 KiB

Open AccessArticle

Effect of Photodynamic Therapy with the Photosensitizer Methylene Blue on Cerebral Endotheliocytes In Vitro

by Vladimir I. Makarov, Alexey S. Skobeltsin, Anton S. Averchuk, Arseniy K. Berdnikov, Milana V. Chinenkova, Alla B. Salmina and Victor B. Loschenov

Photonics 2024, 11(4), 316; https://doi.org/10.3390/photonics11040316 - 28 Mar 2024

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Abstract

Background: Microvessels in tumor tissue play a crucial role in meeting the metabolic needs of transformed cells, controlling the entry of xenobiotics into tumor tissue, and regulating local inflammation that promotes metastasis. Methylene blue has photosensitizing properties and can also affect dysfunctional mitochondria. [...] Read more.

Background: Microvessels in tumor tissue play a crucial role in meeting the metabolic needs of transformed cells, controlling the entry of xenobiotics into tumor tissue, and regulating local inflammation that promotes metastasis. Methylene blue has photosensitizing properties and can also affect dysfunctional mitochondria. Methods: The study was performed on the primary culture of CECs. The cells underwent photodynamic treatment through 660 nm laser irradiation at a power density of 300 mW/cm². The MTT, TMRE, and TUNEL assays were used to assess the survival, redox metabolism, mitochondrial activity, and apoptosis of CECs. Additionally, the metabolic activity of cells was evaluated using FLIM by measuring the fluorescence lifetime of NADH and FAD. Results: When CECs were incubated with MB, there was an increase in mitochondrial activity that was dependent on the concentration of MB. Additionally, mitochondrial activity increased when the CECs were exposed to 660 nm laser irradiation at an energy dose of up to 5 J/cm². Following PDT, a slight shift towards oxidative phosphorylation was observed. Conclusions: In vitro application of MB accumulation or laser irradiation causes a shift in the redox status of CECs towards increased reducing activity, without causing any cell damage. However, the combined action of PS and laser radiation has the opposite effect on the redox status of cells, resulting in an increase in the oxidized form of FAD. Full article

(This article belongs to the Special Issue Phototheranostics: Science and Applications)

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15 pages, 2284 KiB

Open AccessArticle

Bypassing the Heat Risk and Efficacy Limitations of Pulsed 630 nm LED Photobiomodulation Therapy for Anti-Primary Dysmenorrhea: A Prospective Randomized Cross-Over Trial

by Qiqi Fu, Hui Jiang, Jiali Yang, Yafei Li, He Fei, Jianlong Huang, Yinghua Li and Muqing Liu

Photonics 2024, 11(2), 136; https://doi.org/10.3390/photonics11020136 - 31 Jan 2024

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Abstract

In recent years, photobiomodulation (PBM) has attracted widespread attention for the treatment of various causes of pain and inflammation. Primary dysmenorrhea (PD) is a common gynecological condition characterized by severe menstrual pain, and the limited effectiveness and side effects of conventional treatments have [...] Read more.

In recent years, photobiomodulation (PBM) has attracted widespread attention for the treatment of various causes of pain and inflammation. Primary dysmenorrhea (PD) is a common gynecological condition characterized by severe menstrual pain, and the limited effectiveness and side effects of conventional treatments have highlighted the urgent need to develop and identify new adjunct therapeutic strategies. The present study from the perspective of light morphology aimed to bypass the heat risk limitation and evaluate the efficacy and safety of pulsed 630 nm PBM therapy for reducing pain associated with PD. The pulse light parameters were designed according to the transmittance of red light. In this randomized, cross-over design, sham-controlled study, 46 women with PD were included and randomly assigned to either pulsed 630 nm light therapy or white light sham control therapy. The intervention lasted for 20 min per day and was administered for 7 consecutive days before and during menstruation. The results showed that the pulsed 630 nm PBM treatment demonstrated a significant reduction in pain levels compared to the placebo treatment (p < 0.001), with 55.00% of active treatment participants experiencing a pain intensity differential concentration exceeding 50.00%. Moreover, participants reported an improved quality of life during the active treatment phase and generally preferred it as a more effective method for relieving PD. No adverse events or side effects were reported throughout the trial. Based on the results, pulsed 630 nm LED therapy showed significant relief of menstrual pain compared to white light placebo treatment and improved quality of life under certain circumstances. Therefore, this study proposes that pulsed red light PBM therapy may be a promising approach for future clinical treatment of PD. Full article

(This article belongs to the Special Issue Phototheranostics: Science and Applications)

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20 pages, 7997 KiB

Open AccessArticle

NaGdF₄:Yb, Er, Tm Upconversion Nanoparticles for Bioimaging in Shortwave-Infrared Range: Study of Energy Transfer Processes and Composition Optimization

by Daria Pominova, Vera Proydakova, Igor Romanishkin, Sergei Kuznetsov, Kirill Linkov, Nataliya Tabachkova and Anastasia Ryabova

Photonics 2024, 11(1), 38; https://doi.org/10.3390/photonics11010038 - 30 Dec 2023

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Abstract

Upconversion nanoparticles are promising for many applications. For triple-doped nanoparticles (NPs), the luminescence intensity shows a non-linear dependence on the rare-earth ion concentration, making it difficult to obtain bright phosphors with high energy output. We investigated the energy transfer processes in β-NaGdF₄ [...] Read more.

Upconversion nanoparticles are promising for many applications. For triple-doped nanoparticles (NPs), the luminescence intensity shows a non-linear dependence on the rare-earth ion concentration, making it difficult to obtain bright phosphors with high energy output. We investigated the energy transfer processes in β-NaGdF₄:Yb-Er-Tm NPs and considered strategies for increasing the thulium luminescence intensity, in particular, the use of core–shell structures. The luminescence spectra were analyzed in the short-wavelength infrared (SWIR) and visible (VIS) regions. The Er³⁺ and Tm³⁺ luminescence lifetimes in the VIS region were measured to study the energy transfer processes between the active ions. The quenching of the Tm³⁺ luminescence in the SWIR region was observed. However, both Er³⁺ and Tm³⁺ luminescence bands were observed in the VIS range. We attribute these effects to energy transfer between Tm^3+ 3F₄ → ³H₆ and Er^3+ 4I_13/2 → ⁴I_9/2, which occurs due to overlap of Er³⁺ and Tm³⁺ luminescence bands, and also to competition between Er³⁺ and Tm³⁺ for energy transfer from Yb³⁺. For core–shell NPs, when Tm³⁺ and Er³⁺ are separated into adjacent layers, quenching cannot be avoided, likely due to the mutual diffusion of ions during shell synthesis. The most optimal strategy to obtain luminescence in the SWIR range is to use an inert intermediate shell between the layers containing Tm³⁺ and Er³⁺. Full article

(This article belongs to the Special Issue Phototheranostics: Science and Applications)

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