Photochemistry and Photobiology最新文献

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.

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.

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.

Photobiomodulation (PBM) is a non-invasive therapeutic technique that regulates biological processes using primarily low-power lasers or light-emitting diodes (LEDs) to achieve therapeutic effects. Its application has expanded significantly, particularly in the field of cancer therapy. This review provides a comprehensive overview of PBM, elucidating its underlying mechanisms of action and its potential applications in cancer therapy. It highlights the benefits of PBM in reducing side effects of cancer treatments such as acute oral mucositis, radiation dermatitis, lymphedema, neuropathic pain, and radiation enteropathy. Furthermore, the ability of PBM to inhibit cancer cell proliferation and induce apoptosis, and discusses safety concerns of PBM in clinical applications, presenting existing research that emphasizes its significant potential in cancer therapy was summarized. PBM therapy may offer promising new clinical options for managing cancer and mitigating the side effects associated with conventional cancer therapies.

Electronic absorption and fluorescence properties of a red-emission firefly luciferin analog, seMpai, which is water-soluble and shows a neutral pH, were revealed by quantitative spectroscopic measurements in aqueous solutions of pH 2-10. They were analyzed by density functional theory (DFT) calculations, time-dependent DFT calculations, and vibrational analyses using the neutral form of seMpai and its conjugate acids and bases. In a pH 8 solution, which is commonly used for firefly bioluminescence, seMpai showed an absorption maximum at 380 nm. From the theoretical absorption spectra and pH dependence of the normalized concentrations of the neutral form of seMpai and its conjugate acids and bases, it was found that the most abundant chemical species at pH 8 is the carboxylate anion, and the 380-nm absorption band was assigned as the $\pi$ - $\pi$ * transition of this anion. The fluorescence spectrum of seMpai in the pH 8 aqueous solution showed an emission maximum at 534 nm for 380-nm excitation. According to the theoretical pH dependence of the normalized concentrations and theoretical absorption and fluorescence energies of the chemical forms of seMpai, the most reasonable fluorescence pathway at pH 8 is the emission from the first excited singlet state S₁ of the carboxylate anion through its excitation.

A phenanthridine-based fluorogenic probe 5-(2-(prop-2-yn-1-yloxy)phenyl)-7,8,13,14-tetrahydrodibenzo[a,i]phenanthridine (SAAPH) has been successfully synthesized and characterized through nuclear magnetic resonance (NMR) and high resolution mass spectrometry (HRMS) spectral analyses. A low detection limit was attained for identifying Ru³⁺ at a concentration of 151pM with a minimal reaction time of 10 s. Furthermore, incorporating ethylenediaminetetraacetic acid (EDTA) into SAAPH + Ru³⁺ rendered SAAPH a reversible sensor. Fascinatingly, the fluorescence signal of SAAPH was Turn-ON by the interaction with Ru³⁺ resulting in the noticeable emission change from colorless to blue with an emission enhancement fold of 12. The detection mechanism of SAAPH was initiated by an Intramolecular Charge Transfer (ICT), wherein electrons were transferred from the electron-rich phenanthridine moiety containing the propargylic group to the electron-deficient Ru³⁺. Additionally, paper strips were used for fluorescence detection of Ru³⁺. Further, Ru³⁺ was detected in environmental water samples and HeLa cells. Consequently, SAAPH demonstrates a lower detection limit than other fluorescent probes and exhibits strong selectivity and sensitivity toward Ru³⁺.

This paper is a highlight of the paper by Shahbazi et al. in this issue of Photochemistry and Photobiology. In that systematic review with meta-analysis study, the authors selected a total of 47 papers for the systematic review, and from those, 14 papers were eligible for the meta-analysis. The papers included were based on the adjunctive treatment of peri-implant diseases (PIDs) by the use of photodynamic therapy (PDT), photobiomodulation (LLLT), hyperlight, and high-power lasers in combination with mechanical debridement (MD) used as routine treatment. The clinical findings promoted by the adjunctive treatment based on the phototherapies over the peri-implant diseases were investigated and demonstrated through the literature retrieved and discussed. Photodynamic therapy, photobiomodulation, hyperlight, and high-power lasers used as adjunctive treatments to the mechanical debridement rendered significant impact on different clinical outcomes for both mucositis and peri-implantitis diseases. Photodynamic therapy was the most common phototherapy used in the different studies, and it was capable of contributing to the improvement of important clinical parameters such as: BL (Bone Loss), BoP (Bleeding on Probing), CAL (Clinical Attachment Loss), and PD (Probing Depth); however, these improvements seem to be restricted to short-term evaluation. Yet, after long-term follow-ups, the combined use of phototherapies seems to be similar to those from the conventional treatment, especially MD alone. Among the adjunctive phototherapies discussed by Shahbazi et al., PDT and LLLT seem to be more realistic to be used in the daily clinical setting, especially because they can be more accessible to the clinicians.

Jogging is one of the most popular recreational sport activities over four decades and is done at almost all ages to keep fitness and health. Joggers are exposed to solar UV radiation (UVR) and, due to enhanced heat production by physical activity, body coverage by clothes is reduced. This may imply a health risk due to overexposure. However, little research has been undertaken so far to estimate UVR exposure during jogging. Therefore, UVR exposure was measured at seven body sites during jogging under cloud-free conditions for solar elevations between 20° and 60°. Results show that the top of the shoulder is the most exposed body site by receiving 80% of ambient UVR on average and up to 110% under certain conditions. All other body parts receive up to 55% on average and up to 85% in special cases. This indicates further that monotonous body alignment to the sun holds a higher risk than a frequently alternating alignment. Assuming the longest recommended duration for cardiovascular beneficial jogging of 50 min, photosensitive persons need protection of the shoulders from a UV index of 2 onward on an unvaried path and from a UV index of 3 on an all-directional path. Further, results show that measurements of UVR exposure possess an uncertainty of ±15% including mounting.