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

{"title":"Light-activated Zein–curcumin films for the photodynamic inactivation of bacterial biofilms: Continuous vs. intermittent illumination","authors":"Gabriella Nunes Ferreira ,&nbsp;Rafael Ravagnani da Costa ,&nbsp;Guilherme A. Paixão ,&nbsp;Jaison M. Júnior ,&nbsp;Thaila Q. Corrêa ,&nbsp;Antonio S.N. de Aguiar ,&nbsp;Alessandra R. Lima ,&nbsp;Vanderlei S. Bagnato ,&nbsp;Sergio A. Yoshioka ,&nbsp;Lucas D. Dias","doi":"10.1016/j.jphotobiol.2025.113270","DOIUrl":"10.1016/j.jphotobiol.2025.113270","url":null,"abstract":"<div><div>The development of protein-based films derived from plants and agricultural sources has gained significant attention in the medical and food industries due to their broad applicability, sustainability, low cost, and non-toxic nature. Over the years, numerous studies have reported (photo)antimicrobial films aligned with the principles of the circular economy. In this study, zein-based films immobilized with curcumin as a photosensitizer (2.5 % and 5 % <em>w</em>/w) were synthesized and fully characterized using UV–Vis spectroscopy, fluorescence analysis, FT-IR, thermogravimetry (TG), and water contact angle measurements. Their potential for photodynamic applications was assessed through photobleaching analysis, confirming the generation of reactive oxygen species (ROS) at both concentrations. Furthermore, microbiological evaluations were conducted against <em>Staphylococcus aureus</em> biofilms under two different lighting regimes: continuous and intermittent exposure at specific time intervals (0, 6, 12, 18, and 24 h). The films demonstrated promising antimicrobial activity, achieving bacterial inactivation of up to 3.5 log reductions. These findings highlight the potential applications of zein-curcumin films as coatings for medical devices (e.g., endotracheal tubes, catheters) and as sustainable food packaging materials. The incorporation of photoantimicrobial properties into biodegradable films opens new perspectives for their use in healthcare and food preservation.</div></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"272 ","pages":"Article 113270"},"PeriodicalIF":3.7,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145109318","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":"Vascular and tissue effects of photodynamic therapy in a murine cutaneous tumor model","authors":"Mirian Denise Stringasci ,&nbsp;Michelle Barreto Requena ,&nbsp;Clara Maria Gonçalves de Faria ,&nbsp;Fernando Silva Ramalho ,&nbsp;Vanderlei Salvador Bagnato","doi":"10.1016/j.jphotobiol.2025.113269","DOIUrl":"10.1016/j.jphotobiol.2025.113269","url":null,"abstract":"<div><div>Skin cancer is the most common neoplasm worldwide and presents a significant health concern. Topical photodynamic therapy (PDT) has emerged as a therapeutic option for treating malignant and potentially precancerous skin lesions. To improve this technique and design more effective protocols, it is vital to understand the relationship between PDT damage in blood vessels and surrounding tissues. In this study, solid tumors of squamous cell carcinoma (SCC) were induced in balb/c nude mice. Damages were evaluated using histology and optical coherence tomography (OCT) images to compare PDT protocols using systemic and topical photosensitizer (PS) administration with different irradiances. The results are promising and may support the development of new and more effective PDT protocols for clinical treatment, including those that require multiple treatment sessions.</div></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"272 ","pages":"Article 113269"},"PeriodicalIF":3.7,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145109317","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":"Restoration of carious dentin using diode irradiation on unmodified and chitosan nanoparticle-modified adhesive before LED polymerization: A SEM, FTIR, and μTBS evaluation.","authors":"Amer M. Alanazi ,&nbsp;Shaheryar Shafqat ,&nbsp;Muhammad Omar Niaz ,&nbsp;Zainab Dua","doi":"10.1016/j.jphotobiol.2025.113265","DOIUrl":"10.1016/j.jphotobiol.2025.113265","url":null,"abstract":"<div><h3>Aim</h3><div>To investigate the restoration of caries-affected dentin (CAD) using adhesive modification technique via diode laser (DL) irradiation of unmodified and modified adhesive with Chitosan nanoparticles (CHNP) before light emitting diode (LED) polymerization, and CHNPs modified adhesive+LED polymerization without DL on micro-tensile bond strength (μTBS), Degree of conversion (DC) and resin tag length (RTL).</div></div><div><h3>Material and methods</h3><div>Forty-four human mandibular molars were obtained, and CAD was exposed according to ICDAS criteria 5. Teeth were positioned vertically within the auto-cure acrylic resin and randomly distributed into four categories according to the adhesive modification (<em>n</em> = 11). Group1-Etch(E) + Bond(B) + LED,Group 2-E + B(CHNP) + LED, Group 3-E + B + DL + LED and Group 4-E + B(CHNPS) + DL + LED. All samples were restored using composite buildup followed by thermal aging. Surface characterization of CHNP with Energy-dispersive spectroscopy (EDS) was assessed along with RTL via scanning electron microscopy (SEM). μTBS and failure modes were analyzed utilizing a universal testing machine (UTM) and stereomicroscope, respectively. The DC was quantified using a Fourier Transform Infrared Spectroscopy (FTIR). A one-way analysis of variance, complemented by Tukey's post hoc test, was implemented for comparisons among the investigated groups (<em>p</em> &lt; 0.05).</div></div><div><h3>Results</h3><div>Group 4-E + B(CHNP) + DL + LED (<em>107.43 ± 1.55</em> μ<em>m) presented the longest RTL with a score of grade 3 and the highest bond strength</em> (<em>11.54 ± 0.37 MPa). Whereas,</em> Group 1 (E + B+ LED) displayed the shortest RTL (<em>76.63 ± 0.82</em> μ<em>m) and lowest</em> μTBS <em>(9.31</em> ± <em>0.17 MPa).</em> The adhesive irradiated with DL before LED polymerization in Groups 2 and 4 presented comparable DC (p˃0.05).</div></div><div><h3>Conclusion</h3><div>Pre-irradiating both unmodified and modified adhesives with chitosan nanoparticles using a diode laser before LED polymerization seems to be an effective approach. This technique enhances the material's mechanical properties by improving adhesive penetration, which in turn affects the length of resin tags,μTBS, and DC.</div></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"272 ","pages":"Article 113265"},"PeriodicalIF":3.7,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145102985","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":"Dual near-infrared wavelength photobiomodulation accelerates transdermal burn wound repair via anti-inflammatory, pain relief and redox-regulating mechanisms","authors":"Ashok Priyadarshi,&nbsp;Gaurav K. Keshri,&nbsp;Divya Yadav,&nbsp;Asheesh Gupta","doi":"10.1016/j.jphotobiol.2025.113267","DOIUrl":"10.1016/j.jphotobiol.2025.113267","url":null,"abstract":"<div><div>Burns cause severe tissue damage and impose a significant psychological and financial burden, highlighting the need for innovative, effective, and cost-efficient therapeutic interventions for tissue repair. Research indicates that multimodal therapy enhances healing by positively regulating various phases of tissue repair. Photobiomodulation therapy (PBMT), which employs low-power light, offers a promising non-pharmacological energy-based healing approach for non-healing wounds. Absorbed photons stimulate cellular metabolism, increase ATP production, and modulate molecular signaling pathways, thereby facilitating the repair process. In this study, we investigated the effects of combined NIR pulsed 810 nm and superpulsed 904 nm lasers PBMT on inflammation, pain, and redox status during transdermal burn wound healing in rats. Animals were divided into five groups, namely uninjured, control (burn), pulsed 810 nm, superpulsed 904 nm lasers, and dual wavelength PBMT. Combined PBMT exhibited a positive synergistic effect on the burn repair process by significantly (<em>P</em> &lt; 0.05) reducing inflammation (NF-κB, TNF-α, IL-1β, NOS-2, IL-6), pain (substance P-receptor, COX-2), and oxidative stress (ROS, 4-HNE adduct, LPO, 3-NT), while increasing redox potential/endogenous antioxidant (Nrf2, catalase), and maintaining cytoprotection (GRP78) seven days post-wounding. These molecular findings were well-supported by histopathological analysis, which indicated decreased mast cell infiltration, exhibiting the potent anti-inflammatory effects of the combined PBMT. Altogether, the current findings demonstrate that dual PBMT synergistically accelerates the repair of full-thickness burns, exhibits analgesic, anti-inflammatory responses, reduces oxidative stress, activates the antioxidant defense pathway, and maintains cellular redox homeostasis. This non-invasive dual NIR PBMT presents a promising translational therapeutic approach for burn repair in clinical care.</div></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"272 ","pages":"Article 113267"},"PeriodicalIF":3.7,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145091974","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":"Synthesis of new chlorin e6 derivatives bearing galactose moieties on the macrocyclic periphery and their structure–activity relationships","authors":"Marina V. Mal'shakova ,&nbsp;Nikolay D. Belykh ,&nbsp;Lydia N. Shestakova ,&nbsp;Natalia E. Galochkina ,&nbsp;Artem O. Belotelov ,&nbsp;Sergey S. Soroko ,&nbsp;Irina V. Balalaeva ,&nbsp;Dmitry V. Belykh ,&nbsp;Natalia Yu. Shilyagina","doi":"10.1016/j.jphotobiol.2025.113268","DOIUrl":"10.1016/j.jphotobiol.2025.113268","url":null,"abstract":"<div><div>Recent studies of photosensitizers have increasingly focused on improving their aqueous solubility, reducing dark toxicity and enhancing photodynamic activity. In our work, we have synthesized and characterized a series of chlorin e₆ derivatives varying in the number of galactose moieties in the molecule and way they are linked to the chlorin macrocycle. We established that the quantity and localization of galactose moieties in the macrocycle affects both dark and photoinduced cytotoxicity. All of the studied derivatives exhibited singlet oxygen quantum yield photogeneration comparable to that of the clinically approved chlorin e₆ dimeglumine (Photoditazine®) with marginal exceeding. Although the incorporation of galactose moieties to the periphery of the chlorin macrocycle led to slightly decreased photostability of resulting derivatives, it did not significantly hinder their photodynamic activity. Moreover, cellular uptake of the obtained derivatives was significantly improved compared to that of Photoditazine®. Collectively, favorable spectral, photochemical, photobiological characteristics, along with improved aqueous solubility, suggest that chlorin e₆ derivatives with peripheral galactose substituents are promising photosensitizers for clinical applications.</div></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"272 ","pages":"Article 113268"},"PeriodicalIF":3.7,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145251390","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":"In situ sonoporation to enhance the tumour uptake of silicon phthalocyanine and improve PDT effectiveness in a triple negative breast cancer murine model","authors":"Martina Capozza ,&nbsp;Alberto Mangia ,&nbsp;Michela Gagliardi ,&nbsp;Rachele Stefania ,&nbsp;Francesca Garello ,&nbsp;Laura Conti ,&nbsp;Enzo Terreno","doi":"10.1016/j.jphotobiol.2025.113266","DOIUrl":"10.1016/j.jphotobiol.2025.113266","url":null,"abstract":"<div><div>The effectiveness of photodynamic therapy (PDT) has been well demonstrated <em>in vitro</em>, but <em>in vivo</em> studies have only shown a delay in tumour growth. Tumour recurrence is often reported in clinical trials and is usually associated with limited tumour uptake of the photosensitiser (PS). In this study, sonoporation (SNP) is utilised as a physical targeting tool to enhance the uptake of an untargeted PS in cells and tumour tissues. Using a chemometric approach, we identified the optimal sonoporation stimulus to maximise uptake and cell viability (frequency 1.05 MHz, tON (percentage of positive signal in a single pulse): 50 %, DC: 90 %, burst: 1 s, sonoporation time 1 min). We achieved a viability of 83.9 % ± 10.3, and an uptake in live cells of 53.1 % ± 6.6. The combination of sonoporation and photodynamic therapy resulted in a significant reduction in cell viability. In a triple-negative breast cancer model, sonoporation combined with photodynamic therapy significantly inhibited tumour growth. For the first time, our results highlight the potential of sonoporation as a non-invasive method to increase the intratumour uptake of photosensitisers, offering a promising strategy to improve PDT efficacy.</div></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"272 ","pages":"Article 113266"},"PeriodicalIF":3.7,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145102994","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":"Integrated laser speckle contrast and multispectral imaging for in vivo multimodal assessment of small intestinal viability","authors":"Yi Xie ,&nbsp;Danfei Huang ,&nbsp;Jiaxuan Yan ,&nbsp;Libin Zhu ,&nbsp;Tianci Weng ,&nbsp;Lechao Zhang ,&nbsp;Zhonghao Xie ,&nbsp;Guangzao Huang ,&nbsp;Shujat Ali ,&nbsp;Xiaojing Chen","doi":"10.1016/j.jphotobiol.2025.113264","DOIUrl":"10.1016/j.jphotobiol.2025.113264","url":null,"abstract":"<div><div>Accurate intraoperative identification of necrotic intestinal segments remains challenging owing to the limitations of invasive methods or single-parameter techniques. A multimodal system integrating laser speckle contrast and multispectral imaging was developed. The noninvasive system simultaneously acquires images of blood flow index (BFI) and tissue oxygen saturation (StO₂), which enables the assessment of tissue metabolic rate of oxygen (tMRO₂). For in vivo calculation of StO₂ in the small intestine, a linear transformation algorithm based on three hemoglobin isosbestic points was employed, and an optimal characteristic wavelength (763 nm) was selected to reduce background interference. The system was validated in the small intestinal ischemia and reperfusion model of rabbits. During occlusion, BFI and tMRO₂ rapidly declined by approximately 80 %, while StO₂ gradually decreased, ultimately by approximately 46 %. Upon reperfusion, segments with reversible damage exhibited a significant recovery. In contrast, irreversibly necrotic regions showed only transient increases before secondary decline. Although either modality alone can identify necrotic intestinal segments that are indiscernible to the human eye, the location of occluded mesenteric vessels cannot be accurately identified. The multimodal imaging approach resolved this limitation, and enabled reliable identification of potentially and irreversibly necrotic segments, as confirmed by pathological analysis. This system provides a noninvasive and cost-effective solution for intraoperative intestinal viability assessment and surgical precision.</div></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"272 ","pages":"Article 113264"},"PeriodicalIF":3.7,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145091970","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":"Neodymium-doped yttrium vanadate laser and Phthalocyanine photosensitizer doped chitosan nanoparticle activated via Photodynamic therapy on smear layer and push-out bond strength of fiber post: An in vitro SEM, EDX assessment","authors":"Fahad Alkhudhairy","doi":"10.1016/j.jphotobiol.2025.113263","DOIUrl":"10.1016/j.jphotobiol.2025.113263","url":null,"abstract":"<div><h3>Aims</h3><div>To quantify the effectiveness of different root canal sterilants, i.e., Sodium Hypochlorite (NaOCl), Neodymium-doped Yttrium Vanadate (Nd: YVO₄) laser, Phthalocyanine photosensitizer doped Chitosan nanoparticles activated via Photodynamic therapy (Pc-CNPs-PDT), on smear layer (SL) elimination and push out bond strength (PBS) of glass fiber posts (GFPs) bonded to root dentin.</div></div><div><h3>Materials and methods</h3><div>Forty-eight human premolars with an approximate root length measuring 15 ± 1 mm were included. Endodontic treatment was performed using a nickel‑titanium rotary instrument followed by obturation. The post space was prepared, and specimens were allocated to four groups based on the disinfection protocol employed. Group 1 (Saline + EDTA), Group 2 (2.25 % NaOCl + EDTA), Group 3 (Nd: YVO4 laser + EDTA), Group 4 (Pc-CNPs-PDT + EDTA). A scanning electron microscope was used to assess the surface topography of CHNPs, energy-dispersive spectroscopy (EDS), and SL removal efficacy. Each post was luted using a dual-cure resin cement. The bonded specimens were sectioned into slices (coronal, middle, and apical). A universal testing machine and a stereomicroscope were used to test the PBS and failure modes, respectively. The dataset underwent analysis through one-way analysis of variance ANOVA and Tukey's test to determine notable differences among groups (<em>p</em> = 0.05).</div></div><div><h3>Results</h3><div>Coronal section of Group 4 (Pc (CHNPs)-PDT + EDTA) samples exhibited maximum SL removal. Whereas, minimum SL elimination was displayed by Saline pretreated canals at the apical section. Samples irrigated with 2.5 % NaOCl + EDTA and Pc (CHNPs)-PDT + EDTA presented comparable scores of bond integrity at all three root sections.</div></div><div><h3>Conclusion</h3><div>Phthalocyanine photosensitizer doped Chitosan nanoparticles, activated via Photodynamic therapy, can be considered as a suitable alternative to the gold standard technique, NaOCl and EDTA, in removing smear layer and improving glass fiber post adhesion to canal dentin.</div></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"272 ","pages":"Article 113263"},"PeriodicalIF":3.7,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145061208","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":"2025-09-05","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}

{"title":"Skin safety of 233 nm far UV-C ex vivo and in vivo – Pilot study for evaluating different populations and multiple exposures","authors":"Daniela F. Zamudio Díaz ,&nbsp;Constanze Baber ,&nbsp;Holger Klose ,&nbsp;Jan Ruschel ,&nbsp;Sascha Rohn ,&nbsp;Martina C. Meinke ,&nbsp;Johannes Schleusener","doi":"10.1016/j.jphotobiol.2025.113262","DOIUrl":"10.1016/j.jphotobiol.2025.113262","url":null,"abstract":"<div><div>Nosocomial infections remain a major healthcare challenge, underlining the demand for antimicrobial technologies. Far UV-C (200–235 nm) has emerged as a safer alternative to traditional 254 nm UV-C for microbial reduction on skin and wounds but also in occupied spaces due to its strong germicidal properties and minimal skin penetration. However, studies on humans remain limited.</div><div>This study aimed at evaluating the skin safety of 233 nm UV-C for potential applications in antisepsis and public area decontamination. Ex vivo experiments first assessed age-dependent DNA damage before proceeding to in vivo studies. Healthy volunteers of varying skin types and ages underwent single exposures to evaluate the effects of age and pigmentation. Additionally, young and light-skinned volunteers received multiple exposures. Biopsies were collected to assess DNA damage and repair.</div><div>A biocidal dose of 233 nm induced superficial DNA damage, showing lower damage than that induced by suberythemal UV-B exposure, a recognized safe dose for human skin. Older and dark-skinned participants exhibited higher residual DNA damage 24 h-post-exposure compared to younger and lighter-skinned individuals, though nearly complete repair was observed after seven days. Repeated exposures, up to cumulative doses of 120 mJ/cm² and 240 mJ/cm², did not induce significant changes on skin pigmentation, antioxidant activity, or immune response. However, DNA damage accumulation suggested limitations in repair mechanisms over 24 h. These results confirm the safety of a single exposure to 233 nm, but highlight potential risks with repeated applications, emphasizing the need for careful dose regulation and further in vivo studies, including well-established treatments at 222 nm.</div></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"272 ","pages":"Article 113262"},"PeriodicalIF":3.7,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020030","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}