Photochemistry and Photobiology最新文献

Photopharmacology achieves precise photo controlled regulation of drug activity by utilizing the properties of photochromic ligands. In this study, a series of novel azobenzene-based photochromic ligands (ABB1-5) were designed and synthesized, and their biological activities were confirmed to be precisely regulated by light irradiation. Bioassays against larvae of Culex pipiens pallens showed that the activity of ABB1 was significantly enhanced after light exposure, with the median lethal concentration (LC₅₀) decreasing from 27.20 μg/mL before irradiation to 16.99 μg/mL after, a reduction of 10.21 μg/mL, yielding a difference coefficient of 1.60. Similarly, experiments on Tetranychus cinnabarinus demonstrated a remarkable decrease in acaricidal activity for ABB4 after irradiation, as evidenced by an increase in LC₅₀ from 7.01 to 18.40 μg/mL, an increase of 11.39 μg/mL, with a difference coefficient of 2.62. Notably, the light-induced differences in activity exhibited by the ABBs series against both C. pipiens pallens larvae and T. cinnabarinus not only validate the potential of photochromic ligands in the precise optical control of drug efficacy but also offer a novel strategy for delaying the development of resistance to acaricides in phytophagous mites.

Performance of sunscreens is primarily optimized through the development of their organic or mineral filtering systems, that is, the core of their photoprotective action. However, numerous studies have underscored that the homogeneity of the applied deposit is also key to optimize the effectiveness of a given filtering systems. Quantifying the homogeneity of a coating presents a significant challenge, particularly on complex substrates such as skin. Therefore, there is a key challenge in being able to have robust methods to measure deposit homogeneity for both in vitro and in vivo ultraviolet tests. This work focused on developing new quantitative methods for evaluating sunscreen deposit and its homogeneity. Our approach involved adaptation line-field confocal optical coherence tomography, a technique commonly used in biology, to precisely assess the thickness distribution of sunscreen deposit. For this study, we specifically investigated deposit modifications without changing the filtering system, thereby successfully linking variations in deposit thickness and homogeneity directly to filtration performances. This new method not only can be leveraged to advance the development and improvement of new photoprotective technologies but also paves the way for a more comprehensive understanding and characterization of sunscreen applications, both in vivo and in vitro, leading to improved protection.

Previously, we reported that UVB irradiation significantly reduces IKKα mRNA levels, while IKKα protein levels remain stable, a phenomenon maintained by constitutive nitric oxide synthase (cNOS) and NF-κB activity. In this study, we systematically investigated the transcriptional regulation of IKKα in response to UVB, with a focus on the role of cNOS. Using a series of luciferase reporter constructs containing deletions and site-specific mutations in the IKKα promoter, we evaluated promoter activity in HEK293 cells (cNOS-null) and HEK293cNOS cells (stably expressing cNOS). Our data identified two regulatory elements critical for UVB-inducible IKKα promoter activity: the second p53-binding site and the Ets-1 site. cNOS overexpression enhanced both basal and UVB-induced promoter activities in a dose-dependent manner. Interestingly, the promoter region spanning -940 to -438 harbors a repressive element that limits IKKα transcription. Although UVB activates the IKKα promoter, as shown by luciferase activity, it simultaneously inhibits transcriptional elongation. This likely explains the paradoxical reduction in endogenous IKKα mRNA levels. The effect is not due to decreased mRNA stability, highlighting transcriptional elongation as a key regulatory bottleneck. In parallel, in vivo studies using SKH-1 mice chronically exposed to solar-simulated UV (sUV) showed that cNOS knockout mice developed more tumors and exhibited significantly reduced IKKα expression compared to wild-type controls. These results demonstrate that cNOS regulates IKKα at multiple levels-promoter activation, transcriptional elongation, and protein stability. This multilayered control enhances our understanding of UV-induced skin pathogenesis and supports cNOS-IKKα signaling as a potential target for therapeutic intervention in skin cancer.

The photophysical behavior of novel UV-MALDI matrices belonging to the family of hydroxy-nitrobenzoic acids (HNBAs) was investigated in both acetonitrile and methanol solutions, as well as in the solid state, using spectroscopic, luminescence, and photoacoustic techniques. The study focused on the following positional isomers: 2-hydroxy-3-nitrobenzoic acid, 2-hydroxy-4-nitrobenzoic acid, 2-hydroxy-5-nitrobenzoic acid, 3-hydroxy-2-nitrobenzoic acid, 3-hydroxy-4-nitrobenzoic acid, 3-hydroxy-5-nitrobenzoic acid, 4-hydroxy-3-nitrobenzoic acid, and 5-hydroxy-2-nitrobenzoic acid. Most isomers exhibited strong solid-state absorption at the excitation wavelengths commonly used in UV-MALDI technique (>90% at 337 and 355 nm), high photostability, no detectable luminescence, and highly efficient excitation energy dissipation as prompt heat, resembling the behavior of calorimetric references under both N₂- and air-saturated conditions, suggesting a potential role in facilitating desorption/ionization processes in UV-MALDI. These findings provide valuable insight into the performance of HNBAs as matrix candidates.

In this study, we report a novel, eco-friendly, convenient reduction method of nitroarene compounds using TiO₂/PEG 400/sodium ascorbate (NaAsc). In this investigation, for the first time, we used sodium ascorbate to reduce nitroarene (NC) compounds which have significantly increased the efficiency of the reduction process through a proposed triad system (TiO₂/PEG 400/NaAsc). The reaction also progressed well in the presence of two sources of blue and green LED light, and the reduction of other nitroarene compounds under optimal conditions was performed with good to excellent efficiency.

To present the use of PBM associated with physical exercise in the treatment of shoulder impingement syndrome, with its different parameters. The following databases were used: PubMed, Web of Science, Embase, Cochrane, Scopus, and Lilacs. The gray literature included Google Scholar, Open Grey, LIVIVO, and the Brazilian Library of Theses and Dissertations. Ten randomized clinical trials were included. Pain intensity was improved with PBM compared to control [MD = -0.89, 95% CI (-1.38, -0.40), I² 46%, p = 0.0004]. The 3 different times of assessment (at rest, activity, and at night) of pain intensity were not statistically significant and likewise, the combined effect size [SMD = -0.16; 95% CI (-0.43, 0.12), I² 63%, p = 0.26]. A significant improvement in ROM was seen in the PBM group compared to the control [MD = 12.24, 95% CI (7.64, 16.84), I² 85%, p < 0.00001]. The combined effect estimate showed no significant improvement in functionality in the PBM group compared to the control [MD = -1.47, 95% CI (-7.34, 4.41), I² 58%, p = 0.62]. PBM therapy combined with physical exercise is effective in reducing pain and improving the range of motion in individuals with shoulder impingement syndrome.

This study investigated the photobiomodulation effect of pulsed and continuous blue diode laser on osteogenic differentiation and proliferation of periodontal ligament mesenchymal stem cells. Periodontal Ligament Stem cells were seeded in 96-well plates, and 450 nm blue laser irradiation procedure was performed a day after cell seeding. Each experimental group was divided into two subgroups according to their energy density and irradiation duration: Continuous wave (100 mW, 10s, 2 J/cm² and 100 mW, 20 s, 4 J/cm²) and pulse wave (200 mW, 10 s, 2 J/cm² and 200 mW, 20 s, 4 J/cm² and duty cycle 50% for both). Then, all groups were evaluated with a cell viability test (MTT), cell apoptosis (Annexin V) on the second and fourth days after irradiation, Alizarin Red staining on the 14th day after irradiation based on genes. Real-time PCR was conducted 7 and 14 days after irradiation. GAPD gene primers were used as internal control, and OPN, OCN, ALP, and RUNX2 gene primers were used as tests. The one-way ANOVA statistical analysis revealed that cell proliferation in the continuous-irradiated groups was significantly higher than in pulsed groups. However, there is no significant difference in comparison with the control group. Also, pulsed-irradiated groups demonstrated a higher rate of necrosis. The osteogenic differentiation in the continuous groups was more substantial than in the pulsed and the control groups. In comparison to all other study groups, the group that received continuous mode irradiation at an energy density of 2 J/cm², power of 100 mW, and a radiation time of 10 s exhibited significantly higher numbers of calcified nodules and increased expression of OPN, OCN, and ALP genes (p < 0.05). Overall, treating periodontal ligament stem cells with a continuous blue diode laser and appropriate parameters can enhance their osteogenic differentiation and proliferation, accelerating the regeneration of periodontal tissues.

The increasing resistance to conventional antifungal agents, such as Amphotericin B (AmB), has led to a growing demand for alternative therapeutic approaches for Candida albicans, an opportunistic fungal pathogen responsible for infections in immunocompromised patients. This study aimed to evaluate the effectiveness of photodynamic inactivation (PDI) in combination with AmB for controlling C. albicans growth, particularly in its yeast and hyphal forms, and to assess the impact of multiple PDI doses. C. albicans (ATCC 90028) was cultured in yeast and hyphal suspensions that were adjusted to 10⁸ CFU/mL and treated with AmB at varying concentrations (0.065-1.04 μg/mL), with and without PDI. PDI was performed using the photosensitizer curcumin (2.5 μM), activated by a 450 nm LED light source at a fluence of 15 J/cm². The effect of single and repeated PDI doses was evaluated in the fungal biomolecules, which were assessed using Fourier transform infrared (FTIR) spectroscopy. Optical density (OD) measurements quantified fungal growth reduction at 540 nm. The combination of AmB and PDI significantly reduced C. albicans growth, achieving a 75% reduction in the yeast form and an 87.5% reduction in the hyphal form. Two doses of PDI further enhanced antifungal efficacy, particularly against hyphae, which exhibited higher sensitivity to treatment. These findings suggest that PDI enhances the antifungal action of AmB, particularly in more resistant C. albicans forms such as hyphae and biofilms. The observed synergistic effect supports the potential use of PDI as an effective strategy to combat antifungal resistance in clinical applications.

Photodynamic therapy (PDT) is a minimally invasive treatment with low systemic toxicity and immunomodulatory effects, increasingly applied in managing HPV-associated cervical lesions. Toll-like receptors (TLRs) are critical in regulating immune responses in cervical pathology, yet their dynamics under PDT remain underexplored. This study investigates the effect of PDT on TLR2, TLR3, TLR4, and TLR8 expression in cervical epithelial cells ex vivo, considering lesion severity. The results reveal that TLR8 exhibited the most significant reduction across all groups 2 h after PDT, with the strongest suppression in patients with invasive cervical cancer. TLR4 expression decreased by 24% in HPV-infected patients and by 71% in those with cervical cancer, highlighting its potential role in modulating the inflammatory microenvironment post-PDT. TLR3 showed hyperexpression in LSIL and suppression in HSIL/CIN III, although changes were not statistically significant (p > 0.05). TLR2 expression remained unchanged, likely due to HPV type variability. These findings demonstrate that PDT effectively reduces hyperexpression of TLR8, TLR4, and TLR3 in early-stage cervical cancer, suggesting their potential as biomarkers for treatment efficacy. Further research incorporating HPV typing and advanced techniques like liquid biopsy is essential to refine our understanding of TLRs in PDT for HPV-associated cervical lesions.

Peri-implantitis is an inflammatory disease triggered by a dysbiotic biofilm on dental implants, leading to bone loss and potential implant failure. Although nonsurgical and surgical treatments can reduce the inflammatory process, the high prevalence of peri-implantitis suggests that these interventions are not always effective in arresting disease progression. This has prompted increased interest in antimicrobial photodynamic therapy (aPDT), which utilizes photosensitizers (PSs) activated by light to target bacterial infections. Despite promising benefits, aPDT has not yet achieved consistently favorable clinical outcomes. It may be due to the limitations of current PSs, including restricted light activation, insufficient tissue penetration, and variable antimicrobial efficacy. Additionally, the stability and selectivity of PSs are crucial for their effectiveness against pathogenic bacteria. Variations in light delivery systems and treatment protocols may also contribute to inconsistent results across studies. This review will address the clinical challenges of aPDT for peri-implantitis, critically analyzing the shortcomings outlined in existing literature. It will further explore the chemical and biological mechanisms of PSs, providing insight into the underlying causes of clinical limitations. Finally, we will discuss potential improvements in PS compounds and treatment protocols that could enhance the therapeutic potential of aPDT, offering new perspectives on its role in managing peri-implantitis.