Journal of photochemistry and photobiology. B, Biology最新文献

{"title":"Multifaceted impacts of UVB radiation on morphology, cellular dynamics, and behavior in Macrobrachium olfersii larvae","authors":"Giuliam Kátia Strücker,&nbsp;Madson Silveira de Melo,&nbsp;Evelise Maria Nazari","doi":"10.1016/j.jphotobiol.2025.113289","DOIUrl":"10.1016/j.jphotobiol.2025.113289","url":null,"abstract":"<div><div>The incidence of ultraviolet B (UVB) radiation on Earth's surface has been increasing, impacting marine, coastal, and freshwater organisms. Although these organisms may possess molecular, cellular, and behavioral mechanisms to mitigate the effects of UVB radiation, the embryos and larvae of many species lack fully developed protective strategies. In this context, <em>Macrobrachium olfersii</em> is a decapod essential to the energy cycling of aquatic environments. <em>M. olfersii</em> inhabits shallow and clear coastal waters and is, therefore, susceptible to UVB exposure. This study aimed to investigate the complex effects of UVB radiation on <em>M. olfersii</em> larvae by comparing their responses at two stages of exposure—embryonic and post-hatching—across various levels of cellular, morphological, and behavioral damage. Specifically, we examined whether UVB-induced damage in embryos persists into larval development (first set) and whether irradiated larvae exhibit responses to UVB similar to those observed in irradiated embryos (second set). In the first set of experiments, the parameters of larval body length, eye index, and proteins associated with mitophagy were affected. In the second set, these parameters were impacted, along with more pronounced DNA damage, cell proliferation, and apoptosis. Furthermore, both experimental sets decreased larval migration toward illuminated fields, while cell transparency decreased only in the second set. The results reveal carryover effects of UVB radiation on <em>M. olfersii</em> development, with early exposure prompting adaptation and later exposure causing physiological and functional impairments, potentially reducing predator evasion, survival, and reproductive success.</div></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"273 ","pages":"Article 113289"},"PeriodicalIF":3.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145409236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unimodal and bimodal classification methods for breast carcinomas based on laser-induced autofluorescence spectroscopy","authors":"Dedong Guo ,&nbsp;Zewei Ouyang ,&nbsp;Baichuan Long ,&nbsp;Guanwei Zeng ,&nbsp;Zhuocheng Chen ,&nbsp;Maoliang Chen ,&nbsp;Junlang Chen ,&nbsp;Xing Zhang ,&nbsp;Jianfeng Yan ,&nbsp;Pusheng Zhang ,&nbsp;Zhifeng Chen","doi":"10.1016/j.jphotobiol.2025.113299","DOIUrl":"10.1016/j.jphotobiol.2025.113299","url":null,"abstract":"<div><div>Despite its efficiency, real-time capability, and low cost, laser-induced fluorescence spectroscopy has limited classification accuracy in breast carcinoma diagnosis, restricting its clinical application. To address this, we evaluated three steady-state autofluorescence analysis approaches: spectral ratio, piecewise linear fitting, and univariate cubic polynomial fitting. To make the analysis more systematic and objective, a sliding-window mechanism and statistical difference analysis were introduced. Based on these results, a novel composite-feature strategy was proposed through arithmetic combination of slope values across multiple spectral segments, enabling distributed spectral information to be effectively integrated and enhancing classification stability. Under the current sample size, piecewise linear fitting demonstrated superior performance by extracting multiple slope features, one of which achieved 100 % classification. However, ambiguous boundaries limited unimodal generalizability for larger datasets. We then combined the optimal unimodal method—piecewise linear fitting—with time-resolved fluorescence lifetime data for bimodal analysis. This fusion markedly enhanced class separability over unimodal approaches. Furthermore, decision boundaries from support vector machines (SVM) were sharper than those from linear discriminant analysis (LDA). These findings highlight the diagnostic value of spectral slope features and emphasize the enhanced classification performance achieved by combining steady-state with time-resolved data. The proposed method is label-free, low-cost, time-efficient, and shows strong potential for intelligent diagnostics by reducing reliance on subjective interpretation. The observed differences likely arise from structural protein changes (collagen, elastin), altered protein-bound NAD(<em>P</em>)H ratios, elevated FAD, and porphyrin accumulation, reflecting tumor-related metabolic and microstructural changes.</div></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"273 ","pages":"Article 113299"},"PeriodicalIF":3.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145517630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tannic acid prevents UVB-induced skin photoaging by regulating ferroptosis through NRF2/SLC7A11/GPX4 signaling","authors":"Zhiwei Chen ,&nbsp;Lichun Ye ,&nbsp;Linjiao Zhu ,&nbsp;Lei Zhou ,&nbsp;Chiqing Chen ,&nbsp;Qi Wang ,&nbsp;Yan Meng ,&nbsp;Xinyan Chen ,&nbsp;Guohua Zheng ,&nbsp;Junjie Hu ,&nbsp;Zhaohua Shi","doi":"10.1016/j.jphotobiol.2025.113309","DOIUrl":"10.1016/j.jphotobiol.2025.113309","url":null,"abstract":"<div><h3>Background</h3><div>Photoaging is a significant contributor to accelerated skin aging, primarily driven by ultraviolet B (UVB) radiation exposure, which induces damage to skin tissues. Tannic acid (TA), a high-molecular-weight, water-soluble polyphenolic compound abundant in <em>Galla chinensis</em> and other plant sources, exhibits remarkable antioxidant properties. This study aimed to investigate the effects of TA on UVB-induced skin photoaging and to elucidate the molecular mechanisms underlying.</div></div><div><h3>Methods</h3><div>In vitro, TA was applied to UVB-irradiated human skin fibroblast (HSF) cells. we measured cell viability, reactive oxygen species (ROS), markers of cellular senescence, and the activity of antioxidant enzymes. The potential mechanism of TA was explored using RNA sequencing and further verified by Western blotting and administration of ferroptosis inducers. In vivo, we employed a UVB-induced Balb/C mouse model of photoaging to assess epidermal thickness and collagen fiber density. Tissue levels of antioxidant enzymes were also examined, and the expression of mitogen-activated protein kinase (MAPK) and ferroptosis-related protein levels were detected by Western blotting.</div></div><div><h3>Results</h3><div>TA demonstrated efficacy in mitigating UVB-induced photoaging in fibroblasts. It attenuates oxidative stress damage, inhibited the onset of ferroptosis by modulating MAPK signaling, reduces Fe²⁺ accumulation, and activated the NRF2/SLC7A11/GPX4 signaling cascade, thereby alleviating photoaging. Furthermore, TA ameliorated UVB-induced epidermal thickening and collagen disruption in mice.</div></div><div><h3>Conclusion</h3><div>This study underscores the protective effects of TA against UVB-induced photoaging in HSF cells and skin tissue. These findings provide a robust theoretical foundation for the development of TA-based natural products intended for anti-photoaging applications.</div></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"273 ","pages":"Article 113309"},"PeriodicalIF":3.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145541154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photoactivity of Pluronic® F-127 nanoencapsulated hypericin against Leishmania: A promising approach for cutaneous leishmaniasis","authors":"Larissa Ferreira de Oliveira ,&nbsp;Alanis Boer dos Reis ,&nbsp;Ana Paula Rizzo Bueno ,&nbsp;Tiffany Suzawa ,&nbsp;Maria Julia Schiavon Gonçalves ,&nbsp;Anibal Salinas Junior ,&nbsp;Ana Carolina Vieira de Oliveira ,&nbsp;Paulo Cesar Souza Pereira ,&nbsp;Wilker Caetano ,&nbsp;Flavio Augusto Vicente Seixas ,&nbsp;Áquila Carolina Fernandes Herculano Ramos-Milaré ,&nbsp;Daniele Stefanie Sara Lopes Lera-Nonose ,&nbsp;Maria Valdrinez Campana Lonardoni","doi":"10.1016/j.jphotobiol.2025.113292","DOIUrl":"10.1016/j.jphotobiol.2025.113292","url":null,"abstract":"<div><div>Hypericin (HYP) is a naturally occurring naphthodianthrone that has been extensively studied, particularly in combination with photodynamic therapy (PDT), for its therapeutic properties. Encapsulation of HYP with Pluronic® F-127 nanoparticles enhances its bioavailability. Leishmaniasis is a neglected disease and a global health problem, with varying clinical forms caused by <em>Leishmania</em> parasites. Current treatments are limited by high toxicity and relapse, highlighting the need for alternative therapeutics. We investigated the activity of free HYP and that encapsulated with Pluronic® F-127 (HYPF127) in association with PDT against <em>Leishmania (Leishmania) amazonensis.</em> These compounds demonstrated high anti-<em>Leishmania</em> activity when associated with PDT, with IC₅₀ values for promastigote forms of 18 ± 3 μM for HYP and 16 ± 5 μM for HYPF127. Moderate activity against amastigotes was observed at lower concentrations, and prominent macrophage cytotoxicity was detected in the compounds following irradiation, with CC₅₀ of 0.6 ± 0.2 μM for HYPF127 and 0.2 ± 0.1 μM for HYP in murine macrophages. Phosphatidylserine externalization, mitochondrial membrane depolarization, and DNA fragmentation were observed in promastigotes treated with PDT, suggesting the induction of apoptosis. These results are slightly superior to those obtained for HYPF127. <em>In silico</em> evaluation demonstrated the affinity of HYP for trypanothione reductase (TR), suggesting a possible target and mechanism of action through redox homeostasis inhibition in <em>Leishmania</em>. In conclusion, nanoencapsulated photoactivated HYP exhibited promising antileishmanial activity against <em>L</em>. <em>amazonensis</em>, with F-127 enhancing its potential. Therefore, TR inhibition may be involved in the mechanism of action.</div></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"273 ","pages":"Article 113292"},"PeriodicalIF":3.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145420181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improvement of the antimicrobial efficacy of high-intensity blue light against Pseudomonas aeruginosa by discontinuous irradiation","authors":"Tara Fardoust ,&nbsp;Isabell Blassnig ,&nbsp;Paul C. Fuchs ,&nbsp;Jennifer L. Schiefer ,&nbsp;Christian Opländer","doi":"10.1016/j.jphotobiol.2025.113288","DOIUrl":"10.1016/j.jphotobiol.2025.113288","url":null,"abstract":"<div><div>Wound infections caused by <em>Pseudomonas aeruginosa</em> (PA) are a common cause of death due to subsequent sepsis in immunosuppressed burn patients. Blue light at 455 nm exhibits antibacterial properties against PA and may offer a therapeutic option for treating such infections. However, low intensities require longer treatment durations, while high intensities cause temperature-related challenges. We therefore investigated the antibacterial efficacy of discontinuous blue light treatment (DBLT) at high intensity.</div><div>DBLT cycles (up to 8) comprised 3 min of irradiation (300 mW/cm²) followed by a 2, 4, or 8 min pause to deliver the same doses (up to 432 J/cm²) as continuous blue light treatment (CLBT). In suspension assays, DBLT with 4-min pauses was most effective, achieving complete bacterial eradication after 5 cycles, whereas CLBT at the same dose (270 J/cm²) resulted in only a 1-log-level reduction. In a wound contamination model, DBLT (8 cycles, 4-min pauses) reduced bacterial load by 5 log levels, whereas CLBT only reduced it by 1–2 log levels.</div><div>Flow cytometry and the redox-sensitive probe DCFH-DA assessed blue light-induced oxidative stress in PA. DBLT caused more oxidative stress (2-fold) than CLBT. This suggests that pauses in irradiation enhance the production of reactive species, which may accumulate and affect bacterial vitality.</div><div>In conclusion, incorporating defined pause intervals into blue light therapy enhances antibacterial effectiveness, reduces heat development, and may improve clinical outcomes for bacterial infections in burn patients.</div></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"273 ","pages":"Article 113288"},"PeriodicalIF":3.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145468172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and validation of a multi-modal customized device to stimulate in vitro cell culture systems","authors":"Sofia Oliveira ,&nbsp;Francisca Monteiro ,&nbsp;Susana O. Catarino ,&nbsp;Betina B. Hinckel ,&nbsp;Ioannis Sotiropoulos ,&nbsp;Ana Leal ,&nbsp;Filipe S. Silva ,&nbsp;Óscar Carvalho","doi":"10.1016/j.jphotobiol.2025.113306","DOIUrl":"10.1016/j.jphotobiol.2025.113306","url":null,"abstract":"<div><div>This work focuses on the development and validation of a multi-modal stimulation device for <em>in vitro</em> cell culture systems. The device was designed to stimulate cells or tissues placed on 12-well culture plates. It is connected to customized software that controls the parameters of photobiomodulation (PBM) and ultrasound stimulation (US) through light-emitting diodes and piezoelectric disks, respectively. A wide range of stimulation protocols can be explored by modulating central frequency or wavelength, power density, and duration. Four different cell lines were used to validate the safety and functionality of the device. Human osteoblasts, chondrocytes, periodontal ligament fibroblasts, and mouse-derived neuronal cells were cultured and stimulated daily with ultrasound (1.0 MHz, 100 mW/cm², 5 min), light (810 nm, 7.5 mW/cm², 5 min) and combined stimuli. After three days, metabolic activity and proliferation were assessed. Different cell types demonstrated distinct biological responses to the stimuli, as osteoblasts and chondrocytes showed increased metabolic activity after combined stimulation or PBM, while the metabolic activity of human fibroblasts or neuronal-like cells was unchanged after three days. This highlights the importance of a rigorous optimization of stimulation protocols according to the target tissue. The safety of the device and its sterilization conditions were demonstrated as there was no cell death or contamination during <em>in vitro</em> stimulation. This work features a feasible, safe, and effective multi-modal stimulation device that can provide a wide range of stimulation protocols to better understand their effect on cells or tissues.</div></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"273 ","pages":"Article 113306"},"PeriodicalIF":3.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145517629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phage-conjugated chlorin e6: A strategy overcoming phage resistance in biofilm eradication and wound infection therapy of carbapenem-resistant Acinetobacter baumannii","authors":"Jianhui Su ,&nbsp;Siyi Chen ,&nbsp;Zhishen Huang ,&nbsp;Haoxuan He ,&nbsp;Huanhuan Zou ,&nbsp;Xiaoyi Huang ,&nbsp;Yongzhao Xie ,&nbsp;Hongxia Zhao ,&nbsp;Zhenbo Xu ,&nbsp;Tao Lei ,&nbsp;Juan Li ,&nbsp;Haiyan Zeng","doi":"10.1016/j.jphotobiol.2025.113302","DOIUrl":"10.1016/j.jphotobiol.2025.113302","url":null,"abstract":"<div><div>Carbapenem-Resistant <em>Acinetobacter baumannii</em> (CRAB) frequently causes biofilm-related infections that can exhibit extreme resistance to antibiotic therapy. Phage therapy shows promise as an alternative treatment, yet bacteria may develop resistance to it with prolonged use. Phage-photosensitizer combination therapy represents a novel antimicrobial strategy. This study aims to evaluate the efficacy of chlorin e6-functionalized phage in eradicating biofilms and treating CRAB infections, and to assess its sustained after effect following the emergence of phage resistance. The <em>A. baumannii</em> phage (ABP)-chlorin e6 conjugate (ABP-Ce6) was successfully synthesized and characterized. It preserved the phage's absorptive capacity and lytic activity while enhanced reactive oxygen species (ROS) production. Moreover, ABP-Ce6 demonstrated remarkable antibacterial activity comparable to ABP while exceeding that of Ce6, and showed superior performance in both inhibiting biofilm formation and disrupting existing biofilms in CRAB Ab1513. Significantly, although ABP exhibited no efficacy against the phage-resistant CRAB Ab1513-BIM12 due to its inability to achieve irreversible adsorption, the ABP-Ce6 maintained potent antibacterial and biofilm ablation effects against this strain, outperforming free Ce6. This sustained efficacy arises from ABP's reversible adsorption, which still enables proximity-driven Ce6 delivery to the target bacteria. In vivo, the ABP-Ce6 significantly enhanced mice wound healing for infections caused by CRAB Ab1513 and Ab1513-BIM12. In conclusion, ABP-Ce6 exhibits significant efficacy as a therapeutic agent against CRAB infections even after the bacteria develop resistance to phage therapy. This novel strategy may serve as a hopeful complementary strategy to phage therapy, thereby reducing delays in screening for new therapeutic phages.</div></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"273 ","pages":"Article 113302"},"PeriodicalIF":3.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145488967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unveiling connectivity and differences of bacterial response mechanisms exposed to multi-radiation through the transcriptomic profiles and physiological characteristics of Mount Everest Sphingomonas radiodurans","authors":"Yang Liu ,&nbsp;Lu Zhang ,&nbsp;Jinxiu Wang ,&nbsp;Pengcheng Zhang ,&nbsp;Zhuxiang Zhang ,&nbsp;Tuo Chen ,&nbsp;Guangxiu Liu ,&nbsp;Shichang Kang ,&nbsp;Wei Zhang ,&nbsp;Gaosen Zhang","doi":"10.1016/j.jphotobiol.2025.113304","DOIUrl":"10.1016/j.jphotobiol.2025.113304","url":null,"abstract":"<div><div>Radiation-resistant microorganisms employ complex regulatory networks to safeguard cellular protection and DNA repair upon radiation exposure. And, previous studies have focused on a single type of radiation. However, studies specifically exploring the correlations, including connectivity defined as interlinked regulatory networks or coexisted core defense mechanisms, and differences referred to the radiation-type-specific radiation protection and damage repair, between an organism's resistant radiation types and their underlying resistance mechanisms remain limited. Therefore, we conducted an integrated transcriptomic and physiological analysis of <em>Sphingomonas radiodurans</em> from Mount Everest, investigating its connectivity and differences responding to multi-radiations within UVC, γ-ray, and X-ray radiation. For UVC radiation, extracellular polysaccharides reduced direct cell damage, and the RecF homologous recombination pathway was induced to repair DNA DSBs. In response to γ-ray radiation, EPSs also mitigated cell damage; additionally, γ-ray-induced changes in cell membrane proteins and lipids cooperated with EPS to block radiation penetration, and the RecF pathway was activated for DNA DSBs repair. Regarding X-ray radiation, it similarly induced membrane protein and lipid changes to synergize for radiation blocking, but uniquely activated the RecBCD homologous recombination pathway for DNA DSBs repair. Notably, the ROS-scavenging system served as the common connectivity across all three radiation types, mitigating oxidative stress from radiation-induced ROS accumulation. Combined with weighted gene co-expression network analysis, a high proportion of novel genes encoding hypothetical proteins were significantly upregulated in response to multi-radiation. Taken together, these results highlight the coordinated protective strategies of strain S9–5 involving both shared and radiation-specific mechanisms, provide new insights into bacterial response mechanisms of radiation resistance evolution in extreme environments, and serve as important references for developing protection agents against multi-radiation damage.</div></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"273 ","pages":"Article 113304"},"PeriodicalIF":3.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145517669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wavelength-dependent excitation ratio of photosystem I and II in Arabidopsis thaliana","authors":"Peter R. Bos,&nbsp;Herbert van Amerongen,&nbsp;Emilie Wientjes","doi":"10.1016/j.jphotobiol.2025.113278","DOIUrl":"10.1016/j.jphotobiol.2025.113278","url":null,"abstract":"<div><div>Photosynthesis is a finely tuned process in which plants balance excitations between photosystem I (PSI) and photosystem II (PSII) to optimize energy conversion efficiency. The distribution of light energy between PSI and PSII across the full spectrum of photosynthetically active radiation is hard to quantify. Current attempts rely on estimating the PSI/PSII reaction center ratio and PS antenna sizes. In this study, we employed a streak-camera system to measure excitation distribution between PSI and PSII in <em>Arabidopsis thaliana</em> leaves over the wavelength range 430–630 nm, bypassing the need for indirect estimations of antenna size and pigment distribution. Our findings show that the absorption weighted PSII/(PSI + PSII) excitation ratio is 0.60 ± 0.01 in the 430–630 nm spectral range. By fitting the excitation spectrum with absorption spectra of PSI, PSII, and LHCII, we estimate the PSII/(PSI + PSII) reaction center ratio to be 0.58 ± 0.004. The excitation ratio shows that in the dark-adapted supercomplex organisation, PSII is overexcited. By recording a light response curve of ΦPSI and ΦPSII, we determined that the dark-adapted supercomplex organisation leads to overexcitation of PSII in low to medium light illumination intensities (∼372 μmol m⁻² s⁻¹). However, state transitions alone can rebalance the charge separation ratio. The quantitative excitation ratio and its correlation with reaction center ratios provide crucial parameters for refining photosynthetic models and understanding energy distribution across photosystems.</div></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"272 ","pages":"Article 113278"},"PeriodicalIF":3.7,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145267345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Combined nanodiamond-mediated drug delivery and upconversion phototherapy for enhanced liver cancer treatment","authors":"Yun Teng ,&nbsp;Zhige Li ,&nbsp;Zheng Cui ,&nbsp;Linfeng Wan ,&nbsp;Zhuo Li ,&nbsp;Xin Zhang ,&nbsp;Lesheng Teng ,&nbsp;Junsong Liu ,&nbsp;Hongdong Li","doi":"10.1016/j.jphotobiol.2025.113260","DOIUrl":"10.1016/j.jphotobiol.2025.113260","url":null,"abstract":"<div><div>To mitigate the significant side effects and limited efficacy of traditional treatment methods, we propose a novel strategy that involves the use of nanodiamond (ND) drug loading combined with up-converted blue light irradiation to achieve highly efficient chemotherapy-photodynamic treatment of liver tumor cells, specifically for the HepG2 cell line. ND-loaded drugs delivered a high concentration of doxorubicin to HepG2 cells, enhancing the chemotherapy effect. Upon exposure to near-infrared irradiation, blue light is excited by up-conversion nanoparticles (UCNPs), thereby activating the production of reactive oxygen demonstrated that the dual-mode therapy of chemotherapy and photodynamic therapy showed significantly improved anticancer effects. The inhibition rates were 77.4 % in vitro and 88.1 % in vivo for HepG2 cells, which are significantly higher than those treated with single photodynamic therapy (18.9 %, 28.6 %) or drug-loaded therapy (62.6 %, 71.4 %). It is noted that under the treatment conditions, no obvious tissue injury or inflammation was observed in the heart, liver, spleen, lung, and kidney samples collected from mice, indicating that the UCNPs and NDs exhibit good biocompatibility and are less toxic to normal cells and tissues, which would be favorable for clinical applications.</div></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"272 ","pages":"Article 113260"},"PeriodicalIF":3.7,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145046932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}