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15 pages, 4966 KiB

Open AccessArticle

Wavelength-Dependent Calcium Signaling Response to Photobiomodulation in Pancreatic Cells

by Kelli Fowlds, Anne M. Alsup, Abhidha Kunwar, Carly M. Darden, Jacob M. Luber, Michael C. Lawrence and Michael Cho

Photonics 2025, 12(2), 99; https://doi.org/10.3390/photonics12020099 - 23 Jan 2025

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Abstract

Diabetes mellitus is a metabolic disorder that is rapidly growing across the world. Our laboratory has recently demonstrated that photobiomodulation (PBM) can couple to its metabolic pathways by modulating calcium dynamics in islet cells, including α- and β-cells. Using computer vision algorithms, changes [...] Read more.

Diabetes mellitus is a metabolic disorder that is rapidly growing across the world. Our laboratory has recently demonstrated that photobiomodulation (PBM) can couple to its metabolic pathways by modulating calcium dynamics in islet cells, including α- and β-cells. Using computer vision algorithms, changes in PBM-induced calcium dynamics can be verified, and, more importantly, this led us to propose hypotheses that will likely advance our understanding of photostimulatory effects in islet cells. In our previous paper, we determined changes in calcium spiking in response to PBM at 810 nm by manually segmenting the cells and the calcium spiking patterns. We have since developed a computer vison pipeline to automate cell segmentation and subsequent image analyses. By using automated methods for segmentation, registration, tracking, and statistical analysis, we were able to improve the accuracy of previously observed changes in calcium spiking in response to PBM in both cell types. Moreover, this pipeline was applied to elucidate the wavelength-dependent modulation of calcium dynamics at 1064 nm. The extent of increase in calcium spiking appears to have been overestimated by manual analysis, and the machine learning pipeline was able to capture and segment nearly 3-fold more cells, suggesting improved accuracy in the analysis of calcium spiking in islet cells. Detailed calcium analysis also indicates a biphasic dose response among α- and β-cells in response to PBM therapy at different wavelengths. The current findings offer a novel hypothesis and may facilitate the use of translational PBM as a potential therapy for diabetes mellitus. Full article

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

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14 pages, 3418 KiB

Open AccessArticle

Photodynamic Therapy under Diagnostic Control of Wounds with Antibiotic-Resistant Microflora

by Artem Shiryaev, Mikhail Ivankov, Arina Voitova, Nina Kalyagina, Kanamat Efendiev, Tatiana Pisareva, Sergey Zavodnov, Igor Reshetov and Victor Loschenov

Photonics 2024, 11(7), 594; https://doi.org/10.3390/photonics11070594 - 26 Jun 2024

Cited by 2 | Viewed by 1862

Abstract

Background: Difficulties in the treatment of purulent wounds are caused by bacterial biofilms, which results in decontamination limitations. Infected wounds are not sufficiently susceptible to existing antibiotics, necessitating the search for alternative approaches to reduce the concentration of pathogenic microflora. Methods: This study [...] Read more.

Background: Difficulties in the treatment of purulent wounds are caused by bacterial biofilms, which results in decontamination limitations. Infected wounds are not sufficiently susceptible to existing antibiotics, necessitating the search for alternative approaches to reduce the concentration of pathogenic microflora. Methods: This study describes an approach to the effective treatment of wounds by photodynamic inactivation or therapy (PDI/PDT) of antibiotic-resistant microflora under fluorescence control. For this purpose, laser and LED light (660–680 nm) and different groups of photosensitizers (PS) (1% solutions of methylene blue, aluminum phthalocyanine, chlorine e6 and nanocomposites containing these groups of PS) were used. The study included 90 patients with various wounds. Some patients were subjected to fluorescence diagnosis by laser spectral analysis before the PDT. Results: Positive results were achieved in 76 patients (84%, p < 0.05). After the first PDT session, a decrease in the concentration of microflora was noticeable. By the third and seventh days, a significant to complete inactivation of bacteria was obtained. In all patients who were photo-diagnosed before PDT, a significant PS concentration decrease of more than 75% after PDT was obtained. Conclusion: PDT is an effective method for the inactivation of antibiotic-resistant pathogens, including in long non-healing wounds, contributing also to early tissue regeneration. Full article

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

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12 pages, 3781 KiB

Open AccessArticle

Validation of a White Light and Fluorescence Augmented Panoramic Endoscopic Imaging System on a Bimodal Bladder Wall Experimental Model

by Arkadii Moskalev, Nina Kalyagina, Elizaveta Kozlikina, Daniil Kustov, Maxim Loshchenov, Marine Amouroux, Christian Daul and Walter Blondel

Photonics 2024, 11(6), 514; https://doi.org/10.3390/photonics11060514 - 28 May 2024

Cited by 2 | Viewed by 1398

Abstract

Background: Fluorescence visualization of pathologies, primarily neoplasms in human internal cavities, is one of the most popular forms of diagnostics during endoscopic examination in medical practice. Currently, visualization can be performed in the augmented reality mode, which allows to observe areas of increased [...] Read more.

Background: Fluorescence visualization of pathologies, primarily neoplasms in human internal cavities, is one of the most popular forms of diagnostics during endoscopic examination in medical practice. Currently, visualization can be performed in the augmented reality mode, which allows to observe areas of increased fluorescence directly on top of a usual color image. Another no less informative form of endoscopic visualization in the future can be mapping (creating a mosaic) of the acquired image sequence into a single map covering the area under study. The originality of the present contribution lies in the development of a new 3D bimodal experimental bladder model and its validation as an appropriate phantom for testing the combination of bimodal cystoscopy and image mosaicking. Methods: An original 3D real bladder-based phantom (physical model) including cancer-like fluorescent foci was developed and used to validate the combination of (i) a simultaneous white light and fluorescence cystoscopy imager with augmented reality mode and (ii) an image mosaicking algorithm superimposing both information. Results: Simultaneous registration and real-time visualization of a color image as a reference and a black-and-white fluorescence image with an overlay of the two images was made possible. The panoramic image build allowed to precisely visualize the relative location of the five fluorescent foci along the trajectory of the endoscope tip. Conclusions: The method has broad prospects and opportunities for further developments in bimodal endoscopy instrumentation and automatic image mosaicking. Full article

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

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14 pages, 26702 KiB

Open AccessArticle

Polycationic Photosensitizers as Effective Anticancer Agents That Destroy Cancer Stem Cells, Cancer Vascularization and Induce Protective Desmoplastic Reaction around Lung Cancers

by Evgeniya Kogan, Gennady Meerovich, Saida Karshieva, Elena Makarova, Igor Romanishkin, Ekaterina Akhlyustina, Irina Meerovich, Nikolay Zharkov, Sergey Kharnas, Vladimir Levkin, Sofya Demura, Zhilong Chen, Victor Loschenov and Igor Reshetov

Photonics 2024, 11(6), 485; https://doi.org/10.3390/photonics11060485 - 21 May 2024

Cited by 3 | Viewed by 1259

Abstract

PDT using PSs based on polycationic derivatives of synthetic bacteriochlorin against Lewis lung carcinoma provides effective inhibition of tumor growth with an increase in the lifespan and survival of mice in the group. PDT with polycationic photosensitizers destroys CSCs and tumor neovascularization, and [...] Read more.

PDT using PSs based on polycationic derivatives of synthetic bacteriochlorin against Lewis lung carcinoma provides effective inhibition of tumor growth with an increase in the lifespan and survival of mice in the group. PDT with polycationic photosensitizers destroys CSCs and tumor neovascularization, and activates the desmoplastic reaction. These results open up new opportunities for increasing the effectiveness of treatment and reducing the incidence of relapses and metastases after PDT. Full article

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

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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

Cited by 1 | Viewed by 2902

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

Cited by 3 | Viewed by 2391

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

Cited by 3 | Viewed by 2304

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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Review

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28 pages, 2884 KiB

Open AccessReview

Machine Learning and Artificial Intelligence Systems Based on the Optical Spectral Analysis in Neuro-Oncology

by Tatiana Savelieva, Igor Romanishkin, Anuar Ospanov, Sergey Goryaynov, Galina Pavlova, Igor Pronin and Victor Loschenov

Photonics 2025, 12(1), 37; https://doi.org/10.3390/photonics12010037 - 4 Jan 2025

Cited by 1 | Viewed by 1081

Abstract

Decision support systems based on machine learning (ML) techniques are already empowering neuro-oncologists. These systems provide comprehensive diagnostics, offer a deeper understanding of diseases, predict outcomes, and assist in customizing treatment plans to individual patient needs. Collectively, these elements represent artificial intelligence (AI) [...] Read more.

Decision support systems based on machine learning (ML) techniques are already empowering neuro-oncologists. These systems provide comprehensive diagnostics, offer a deeper understanding of diseases, predict outcomes, and assist in customizing treatment plans to individual patient needs. Collectively, these elements represent artificial intelligence (AI) in neuro-oncology. This paper reviews recent studies which apply machine learning algorithms to optical spectroscopy data from central nervous system (CNS) tumors, both ex vivo and in vivo. We first cover general issues such as the physical basis of the optical-spectral methods used in neuro-oncology, and the basic algorithms used in spectral signal preprocessing, feature extraction, data clustering, and supervised classification methods. Then, we review in more detail the methodology and results of applying ML techniques to fluorescence, elastic and inelastic scattering, and IR spectroscopy. Full article

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

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