Journal of Photochemistry and Photobiology. B, Biology

The effects of silver nanoparticles (AgNPs), both alone and in combination with mineral nutrients, on the growth and photosynthesis of Solanum lycopersicum plants during ontogeny were studied. The experiment involved weekly applications of 10 μmol of AgNPs for 15 weeks in a greenhouse over a summer period. A comprehensive characterization of the AgNPs was performed via TEM, ESI/EELS, and zeta potential measurements before and throughout the experiment. The activity of PSII, stomatal conductivity, photosynthesis, transpiration and respiration rates were measured, and the photosynthetic pigments, chloroplast ultrastructure, and dry and fresh masses of leaves, roots, and fruits were assessed...

An integrated system for in vivo multi-spectral imaging (MSI) and Raman spectroscopy was developed to understand the external morphology and internal molecular information of biological tissues. The achieved MSI images were reconstructed by eighteen separated images from 400 nm to 760 nm, whose illumination bands were selected with six tri-channel band filters. Based on the spectral analysis algorithms, the spatial distribution patterns of blood volume, blood oxygen content and tissue scatterer volume fraction were visualized...

Exposure to artificial blue light, one of the most energetic forms of visible light, can increase oxidative stress in retinal cells, potentially enhancing the risk of macular degeneration. Retinal pigment epithelial (RPE) cells play a crucial role in this process; the loss of RPE cells is the primary pathway through which retinal degeneration occurs. In RPE cells, Kelch-like ECH-associated protein 1 (KEAP1) is located in both the nucleus and cytosol, where it binds to nuclear factor erythroid 2-related factor 2 (NRF2) and p62 (sequestosome-1), respectively...

Reproductive biotechnologies are widely consolidated as a methodology in cattle breeding and have an important impact on the genetic improvement of cattle herds. Semen is an important source of dissemination of pathogenic microorganisms during reproductive procedures. To ensure the sanitary quality of the semen, it is essential to consider the presence of various microorganisms including viruses. One of the main viral agents of reproductive interest is Bovine Alphaherpesvirus 1 (BoHV-1), the etiological agent responsible for bovine rhinotracheitis and vulvovaginitis and frequently associated with reproductive efficiency of matrices and bulls...

BACKGROUND: Hospital water systems represent critical environments for the transmission of pathogens, including multidrug-resistant strains like mucoid Pseudomonas aeruginosa (M-PA). Conventional disinfection methods often struggle to eradicate these pathogens effectively, highlighting the need for innovative approaches. OBJECTIVE: This study aimed to develop an enhanced photodynamic disinfection strategy targeting M-PA from hospital water systems, using curcumin-mediated photodynamic inactivation (PDI) with specific spectral range...

Expansion Microscopy (ExM) is a widely used super-resolution technique that enables imaging of structures beyond the diffraction limit of light. However, ExM suffers from weak labeling signals and expansion distortions, limiting its applicability. Here, we present an innovative approach called Tetrahedral DNA nanostructure Expansion Microscopy (TDN-ExM), addressing these limitations by using tetrahedral DNA nanostructures (TDNs) for fluorescence labeling. Our approach demonstrates a 3- to 10-fold signal amplification due to the multivertex nature of TDNs, allowing the modification of multiple dyes...

Prolonged exposure of human dermal fibroblasts (HDF) to ultraviolet (UV) radiation triggers the production of reactive oxygen species by upregulating the expression of matrix metalloproteinases (MMPs), causing type-I collagen degradation and photoaging. A sulfated (1 → 3)/(1 → 4) mannogalactan exopolysaccharide (BVP-2) characterized as [→3)-α-Galp-{(1 → 4)-α-6-O-SO3 -Manp}-(1 → 3)-α-6-O-SO3 -Galp-(1→] was isolated from seaweed-associated heterotrophic bacterium Bacillus velezensis MTCC13097...

BACKGROUND/AIM: This experimental study aimed to examine the effectiveness of transdermal antimicrobial photodynamic therapy (APDT) with and without antimicrobial lock therapy (ALT), on catheter biofilms. METHODS: S. epidermidis and C. orthopsilosis biofilms were formed within peripheral venous catheters positioned in the marginal ear veins of New Zealand white rabbits. Biofilm formation was confirmed with scanning electron microscopy in two catheters. 24 catheters with staphylococcal biofilms and 24 with fungal biofilms were treated with APDT, ALT or "APDT plus ALT" for five days...

Two monocarbonyl dimethylamino curcuminoids, one derived from acetone (C3) and the second one from cyclohexane (C6), were synthesized aiming to study their photophysical properties and anticancer photodynamic potential. Compound C6 exhibited lower absorbance and fluorescence than C3. Photobleaching studies showed that C3 and C6 photostability behavior in DMSO differ significantly. C3 was completely photoconverted into a new species absorbing at lower wavelength than the parent compound, whereas, C6, upon a 30 min irradiation at λ = 440 nm with 15 mW/cm2 reached a photostationary phase where a smaller amount of the initial compound coexists with some photoproducts of higher and lower absorbance...

Ovarian aging is a serious clinical concern. Few safe and effective methods are currently available to improve ovarian functions. Photobiomodulation (PBM) is a safe and noninvasive physical therapy that can modulate a series of biological processes. Recently, several studies have noted its potential to improve the function of ovary and reproductive cells. However, the effects of PBM treatment on natural ovarian aging remain unclear. In this study, we used a naturally reproductive aging mouse model to observe the effect of PBM on ovarian function...

Pseudomonas aeruginosa, a notable pathogen frequently associated with hospital-acquired infections, displays diverse intrinsic and acquired antibiotic resistance mechanisms, posing a significant challenge in infection management. Antimicrobial blue light (aBL) has been demonstrated as a potential alternative for treating P. aeruginosa infections. In this study, we investigated the impact of blue light wavelength, bacterial growth stage, and growth medium composition on the efficacy of aBL. First, we compared the efficacy of light wavelengths 405 nm, 415 nm, and 470 nm in killing three multidrug resistant clinical strains of P...

Alzheimer's disease, a prevalent neurodegenerative condition primarily affecting older adults, remains incurable. Its principle pathological hallmark is the accelerated accumulation of amyloid β (Aβ) protein. This study investigates the potential of photobiomodulation using near infrared light to counteract Aβ1-42 -induced synaptic degeneration and neurotoxicity. We focused on the effect of 808 nm near-infrared laser diode (LD) on Aβ1-42 cytotoxicity in primary cultured cortical neurons...

While solar ultraviolet radiation (UVR) is known to impact zooplankton, little has been documented on its impacts under elevated pCO2 . Here, we show that exposure to UVR decreased the feeding and survival rates of the copepod Acartia spinicauda, that artificial UV-B of 2.25 W·m-2 for 4 h resulted in a 52 % inhibition of its grazing rates and a 45 % reduction in survival rates compared to visible light alone. On the other hand, an increase in pCO2 to 1000 μatm (pH drop of 0.4) immediately and significantly increased the UVR-induced inhibition of feeding...

Photobiomodulation therapy (PBMT) is a form of treatment commonly used for routine clinical applications, such as wound healing of the skin and reduction of inflammation. Additionally, PBMT has been explored for its potential in pain relief. In this work, we investigated the effect of PBMT on ion content within the 50B11 sensory neurons cell line in vitro using X-Ray fluorescence (XRF) and atomic force microscope (AFM) analysis. Two irradiation protocols were selected utilizing near-infrared laser lights at 800 and 970 nm, with cell fixation immediately following irradiation...

As terahertz (THz) technology advances, the interaction between THz radiation and the living body, particularly its effects on the immune system, has attracted extensive attention but remains poorly understood. This study firstly elucidated that exposure to 3 THz-FEL radiation markedly suppressed contact hypersensitivity reactions in mice induced by DNFB, as evidenced by a reduction in ear thickness and a discernible recovery in the Th1/Th2 cell balance. 3 THz irradiation led to cellular stress in the irradiated skin locale, increasing the levels of IL-4 and IL-10 and modulating the activity and migration of dendritic cells and mast cells...

Early leaf senescence affects photosynthetic efficiency and limits growth during the late production stage of winter wheat (Triticum aestivum). Natural variation in photosystem response to senescence represents a valuable resource for improving the aging traits of flag leaves. To explore the natural variation of different phases of photosynthetic electron transport in modern wheat cultivars during senescence, we exposed the flag leaves of 32 wheat cultivars to dark conditions to induce senescence process, and simultaneously measured prompt fluorescence and modulated 820 nm reflection...

Previous studies have demonstrated the efficacy of betahistine mesylate in treating vertigo and angioneurotic headache, enhancing microcirculation, and facilitating histamine release. However, limited research has been conducted on the drug's potential in mitigating blue light-induced damage. Thus, this study utilized Drosophila as the model organism and employed the Siler model to investigate the impact of various concentrations of betahistine mesylate on the lifespan, under 3000 lx blue light irradiation...

Photodynamic therapy (PDT) is a clinically-approved cancer treatment that is based on production of cytotoxic reactive oxygen species to induce cell death. However, its efficiency depends on distribution of photosensitizer (PS) and depth of light penetration through the tissues. Tendency of pathological cancer tissues to exhibit lower pH than healthy tissues inspired us to explore dual-targeted pH-activatable photosensitizers based on tunable near-infrared (NIR) boron-dipyrromethene (BODIPY) dyes. Our BODIPY PSs were designed to carry three main attributes: (i) biotin or cRGD peptide as an effective cancer cell targeting unit, (ii) amino moiety that is protonated in acidic (pH <6...

This review comprehensively examines the phenomenon of photoinhibition in plants, focusing mainly on the intricate relationship between photodamage and photosystem II (PSII) repair and the role of PSII extrinsic proteins and protein phosphorylation in these processes. In natural environments, photoinhibition occurs together with a suite of concurrent stress factors, including extreme temperatures, drought and salinization. Photoinhibition, primarily caused by high irradiance, results in a critical imbalance between the rate of PSII photodamage and its repair...

The hypoxic environment within a solid tumor is a limitation to the effectiveness of photodynamic therapy. Here, we demonstrate the use of oxygen generating nanozymes (CeO2 , Fe3 O4 , and MnO2 ) to improve the photodynamic effect. The optimized combination of process parameters for irradiation was obtained using the Box Behnken experimental design. Indocyanine green, IR 820, and their different combinations with oxygen generators were studied for their effect on oral carcinoma. Dynamic light scattering technique showed the average particle size of CeO2 , MnO2 , and Fe3 O4 to be 211 ± 16, and 157 ± 28, 143 ± 19 nm with PDI of 0...