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

{"title":"Use of parvovirus B19-like particles in self-illuminated photodynamic therapy for solid tumors","authors":"Ángel de Jesús Jiménez-Chávez ,&nbsp;Leticia Moreno-Fierros ,&nbsp;Maribel Cayetano-Cruz ,&nbsp;Laura Patricia Romero-Romero ,&nbsp;Ismael Bustos-Jaimes","doi":"10.1016/j.jphotobiol.2024.112979","DOIUrl":"https://doi.org/10.1016/j.jphotobiol.2024.112979","url":null,"abstract":"<div><p>Bioluminescence resonance energy transfer photodynamic therapy, which uses light generated by bioluminescent proteins to activate photosensitizers and produce reactive oxygen species without the need for external irradiation, has shown promising results in cancer models. However, the characterization of delivery systems that can incorporate the components of this therapy for preferential delivery to the tumor remains necessary. In this work, we have characterized parvovirus B19-like particles (B19V-VLPs) as a platform for a photosensitizer and a bioluminescent protein. By chemical and biorthogonal conjugation, we conjugated rose Bengal photosensitizer and firefly luciferase to B19V-VLPs and a protein for added specificity. The results showed that B19V-VLPs can withstand decoration with all three components without affecting its structure or stability. The conjugated luciferase showed activity and was able to activate rose Bengal to produce singlet oxygen without the need for external light. The photodynamic reaction generated by the functionalized VLPs-B19 can decrease the viability of tumor cells <em>in vitro</em> and affect tumor growth and metastasis in the 4 T1 model. Treatment with functionalized VLPs-B19 also increased the percentage of CD4 and CD8 cell populations in the spleen and in inguinal lymph nodes compared to vehicle-treated mice. Our results support B19V-VLPs as a delivery platform for bioluminescent photodynamic therapy components to solid tumors.</p></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"258 ","pages":"Article 112979"},"PeriodicalIF":3.9,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1011134424001398/pdfft?md5=9269891002fb6b96a970e093efb50add&pid=1-s2.0-S1011134424001398-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141606589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photodynamic activation of phytochemical-antibiotic combinations for combatting Staphylococcus aureus from acute wound infections","authors":"Ariana S.C. Gonçalves ,&nbsp;Miguel M. Leitão ,&nbsp;José R. Fernandes ,&nbsp;Maria José Saavedra ,&nbsp;Cristiana Pereira ,&nbsp;Manuel Simões ,&nbsp;Anabela Borges","doi":"10.1016/j.jphotobiol.2024.112978","DOIUrl":"10.1016/j.jphotobiol.2024.112978","url":null,"abstract":"<div><p><em>Staphylococcus aureus</em> is characterized by its high resistance to conventional antibiotics, particularly methicillin-resistant (MRSA) strains, making it a predominant pathogen in acute and chronic wound infections. The persistence of acute <em>S. aureus</em> wound infections poses a threat by increasing the incidence of their chronicity. This study investigated the potential of photodynamic activation using phytochemical-antibiotic combinations to eliminate <em>S. aureus</em> under conditions representative of acute wound infections, aiming to mitigate the risk of chronicity. The strategy applied takes advantage of the promising antibacterial and photosensitising properties of phytochemicals, and their ability to act as antibiotic adjuvants. The antibacterial activity of selected phytochemicals (berberine, curcumin, farnesol, gallic acid, and quercetin; 6.25–1000 μg/mL) and antibiotics (ciprofloxacin, tetracycline, fusidic acid, oxacillin, gentamicin, mupirocin, methicillin, and tobramycin; 0.0625–1024 μg/mL) was screened individually and in combination against two <em>S. aureus</em> clinical strains (methicillin-resistant and -susceptible–MRSA and MSSA). The photodynamic activity of the phytochemicals was assessed using a light-emitting diode (LED) system with blue (420 nm) or UV-A (365 nm) variants, at 30 mW/cm² (light doses of 9, 18, 27 J/cm²) and 5.5 mW/cm² (light doses of 1.5, 3.3 and 5.0 J/cm²), respectively. Notably, all phytochemicals restored antibiotic activity, with 9 and 13 combinations exhibiting potentiating effects on MSSA and MRSA, respectively. Photodynamic activation with blue light (420 nm) resulted in an 8- to 80-fold reduction in the bactericidal concentration of berberine against MSSA and MRSA, while curcumin caused 80-fold reduction for both strains at the light dose of 18 J/cm². Berberine and curcumin-antibiotic combinations when subjected to photodynamic activation (420 nm light, 10 min, 18 J/cm²) reduced <em>S. aureus</em> culturability by ≈9 log CFU/mL. These combinations lowered the bactericidal concentration of antibiotics, achieving a 2048-fold reduction for gentamicin and 512-fold reduction for tobramycin. Overall, the dual approach involving antimicrobial photodynamic inactivation and selected phytochemical-antibiotic combinations demonstrated a synergistic effect, drastically reducing the culturability of <em>S. aureus</em> and restoring the activity of gentamicin and tobramycin.</p></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"258 ","pages":"Article 112978"},"PeriodicalIF":3.9,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1011134424001386/pdfft?md5=b361d9978298b537d97ad7d3166b4eac&pid=1-s2.0-S1011134424001386-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141603753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computational modelling of the therapeutic outputs of photodynamic therapy on spheroid-on-chip models","authors":"Hossein Kazempour ,&nbsp;Fatemeh Teymouri ,&nbsp;Maryam Khatami ,&nbsp;Seyed Nezamedin Hosseini","doi":"10.1016/j.jphotobiol.2024.112960","DOIUrl":"10.1016/j.jphotobiol.2024.112960","url":null,"abstract":"<div><p>Photodynamic therapy (PDT) is a medical radio chemotherapeutic method that uses light, photosensitizing agents, and oxygen to produce cytotoxic compounds, which eliminate malignant cells. Recently, Microfluidic systems have been used to analyse photosensitizers (PSs) due to their potential to replicate in vivo environments. While prior studies have established a strong correlation between reacted singlet oxygen concentration and PDT-induced cellular death, the effects that the ambient fluid flow might have on the concentration of oxygen and PS have been disregarded in many, which limits the reliability of the results. Herein, we coupled the transport of oxygen and PS throughout the ambient medium and within the spheroidal multicellular aggregate to initially study the profiles of oxygen and PS concentration alongside PDT-induced cellular death throughout the spheroid before and after radiation. The attained results indicate that the PDT-induced cellular death initiates on the surface of the spheroids and subsequently spreads to the neighbouring regions, which is in great accordance with experimental results. Afterward, the effects that drug-light interval (DLI), fluence rate, PS composition, microchannel height, and inlet flow rate have on the therapeutic outcomes are studied. The findings show that adequate DLI is critical to ensure uniform distribution of PS throughout the medium, and a value of 5 h was found to be sufficient. The composition of PS is critical, as ALA-PpIX induces earlier cell death but accelerates oxygen consumption, especially in the outer layers, depriving the inner layers of oxygen necessary for PDT, which in turn disrupts and prolongs the exposure time compared to mTHPC and Photofrin. Despite the fluence rate directly influencing the singlet oxygen generation rate, increasing the fluence rate by 189 mW/cm² would not significantly benefit us. Microwell height and inlet flow rate involve competing phenomena—increasing height or decreasing flow reduces oxygen supply and increases PS “washout” and its concentration.</p></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"258 ","pages":"Article 112960"},"PeriodicalIF":3.9,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141590583","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":"Construction and synergistic anti-tumor study of a tumor microenvironment-based multifunctional nano-drug delivery system","authors":"Baoqing Liu ,&nbsp;Qinghua Zheng ,&nbsp;Xiandong Shi ,&nbsp;Jian Shen ,&nbsp;Ruyan Li ,&nbsp;Jiahong Zhou","doi":"10.1016/j.jphotobiol.2024.112977","DOIUrl":"10.1016/j.jphotobiol.2024.112977","url":null,"abstract":"<div><p>To solve the problems existing in the clinical application of hypericin (Hyp) and tirapazamine (TPZ), a nano-drug delivery system with synergistic anti-tumor functions was constructed using mesoporous silica nanoparticles (MSN) and sodium alginate (SA). The system exhibited excellent stability, physiological compatibility and targeted drug release performance in tumor tissues. In the in vitro and in vivo experiments, Hyp released from MSN killed tumor cells through photodynamic therapy (PDT). The degree of hypoxia in the tumor tissue site was exacerbated, enabling TPZ to fully exert its anti-tumor activity. Our studies suggested that the synergistic effects between the components of the nano-drug delivery system significantly improve the anti-tumor properties of Hyp and TPZ.</p></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"258 ","pages":"Article 112977"},"PeriodicalIF":3.9,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141590584","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":"The transcriptional changes of LrgA discriminates the responsiveness of Staphylococcus aureus towards blue light from that of photodynamic inactivation","authors":"Ruili Yang ,&nbsp;Yi Xu ,&nbsp;Jinchun Xu ,&nbsp;Yali Li,&nbsp;Xiaoxiao Wan,&nbsp;Rui Kong,&nbsp;Chao Ding,&nbsp;Han Tao,&nbsp;Hui-Li Wang","doi":"10.1016/j.jphotobiol.2024.112967","DOIUrl":"10.1016/j.jphotobiol.2024.112967","url":null,"abstract":"<div><p>Antimicrobial blue light (aBL) is utilized as a new approach to inhibit the growth of <em>Staphylococcus aureus</em> (<em>S. aureus</em>). Mediated by the endogenous chromophore, aBL possesses the similar photokilling property with aPDI (antimicrobial photodynamic inactivation), however, their mechanistic discrepancies in triggering the death of staphylococcal cells are not yet understood. Here, we describe the use of a 460-nm-LED to curb the viability of <em>S. aureus</em>. According to the results, the bacterial survival was sharply decreased when blue light was applied, reaching a maximum of 4.11 ± 0.04 log10 units. Moreover, the membrane integrity was damaged by aBL, causing the leakage of intracellular DNA. Transcriptomic analysis indicates the divergent gene expression upon either aBL or aPDI, with pathways such as transport, DNA repair, expression regulation and porphyrin massively affected by aBL. Among the commonly regulated genes, LrgA was underpinned on account of its involvement with biofilm formation and protein transport. By comparing the wildtype with the LrgA-overexpressing (LrgA+) strain, the survival rate, membrane penetration, surface structure and biofilm formation were, to a varying degree, improved for LrgA+, which may suggest that LrgA plays essential roles in modulating the responsiveness of <em>S. aureus</em>. Besides, LrgA may function through regulating the expression of autolysis-related systems. Finally, LrgA overexpression did not attenuate but aggravate the impairment induced by aPDI, showcasing a distinct responsive strategy from aBL. Taken together, this study unveils a unique molecular alteration for the aBL-mediated inactivation, providing the basis of utilizing blue light to reduce the harm brought by <em>S. aureus</em>.</p></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"258 ","pages":"Article 112967"},"PeriodicalIF":3.9,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141600264","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 the critical role of K+ for xanthorhodopsin expression in E. coli","authors":"Chenda Hour ,&nbsp;Kimleng Chuon ,&nbsp;Myung-chul Song ,&nbsp;Jin-gon Shim ,&nbsp;Shin-Gyu Cho ,&nbsp;Kun-Wook Kang ,&nbsp;Ji-Hyun Kim ,&nbsp;Kwang-Hwan Jung","doi":"10.1016/j.jphotobiol.2024.112976","DOIUrl":"10.1016/j.jphotobiol.2024.112976","url":null,"abstract":"<div><p>Xanthorhodopsin (XR), a retinal-binding 7-transmembrane protein isolated from the eubacterium <em>Salinibacter ruber</em>, utilizes two chromophores (retinal and salinixanthin (SAL)) as an outward proton pump and energy-donating carotenoid. However, research on XR has been impeded owing to limitations in achieving heterogeneous expression of stable forms and high production levels of both wild-type and mutants. We successfully expressed wild-type and mutant XRs in <em>Escherichia coli</em> in the presence of K⁺. Achieving XR expression requires significant K⁺ and a low inducer concentration. In particular, we highlight the significance of Ser-159 in helix E located near Gly-156 (a carotenoid-binding position) as a critical site for XR expression. Our findings indicate that replacing Ser-159 with a smaller amino acid, alanine, can enhance XR expression in a manner comparable to K⁺, implying that Ser-159 poses a steric hindrance for pigment formation in XR. In the presence of K⁺, the proton pumping and photocycle of the wild-type and mutants were characterized and compared; the wild-type result suggests similar properties to the first reported XR isolation from the <em>S. ruber</em> membrane fraction. We propose that the K⁺ gradient across the cell membrane of <em>S. ruber</em> serves to uphold the membrane potential of the organism and plays a role in the expression of proteins, such as XR, as demonstrated in our study. Our findings deepen the understanding of adaptive protein expression, particularly in halophilic organisms. We highlight salt selection as a promising strategy for improving protein yield and functionality.</p></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"258 ","pages":"Article 112976"},"PeriodicalIF":3.9,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1011134424001362/pdfft?md5=218a786c2eadcb43d4db781ec88cb7ff&pid=1-s2.0-S1011134424001362-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141603718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization, DFT study and evaluation of antioxidant potentials of mycosporine-like amino acids (MAAs) in the cyanobacterium Anabaenopsis circularis HKAR-22","authors":"Varsha K. Singh ,&nbsp;Bhanuranjan Das ,&nbsp;Sapana Jha ,&nbsp;Palak Rana ,&nbsp;Rajnish Kumar ,&nbsp;Rajeshwar P. Sinha","doi":"10.1016/j.jphotobiol.2024.112975","DOIUrl":"https://doi.org/10.1016/j.jphotobiol.2024.112975","url":null,"abstract":"<div><p>The physiological parameters such as growth, Chl <em>a</em> content, and photosynthetic performance of the experimental cyanobacterium <em>Anabaenopsis circularis</em> HKAR-22 were estimated to evaluate the cumulative effects of photosynthetically active radiation (PAR) and ultraviolet (UV) radiation. Maximum induction of UV-screening molecules, MAAs, was observed under the treatment condition of PAR + UV-A + UV-B (PAB) radiations. UV/VIS absorption spectroscopy and HPLC-PDA detection primarily confirmed the presence of MAA-shinorine (SN) having absorption maxima (λ_max) at 332.3 nm and retention time (RT) of 1.47 min. For further validation of the presence of SN, HRMS, FTIR and NMR were utilized. UV-stress elevated the <em>in vivo</em> ROS scavenging and <em>in vitro</em> enzymatic antioxidant capabilities. SN exhibited substantial and concentration-dependent antioxidant capabilities which was determined utilizing 2,2-diphenyl-1-picryl-hydrazyl (DPPH), 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate (ABTS), ferric reducing power (FRAP) and superoxide radical scavenging assay (SRSA). The density functional theory (DFT) method using B3LYP energy model and 6-311G++(d,p) basis set was implied to perform the quantum chemical calculation to systematically investigate the antioxidant nature of SN. The principal pathways involved in the antioxidant reactions along with the basic molecular descriptors affecting the antioxidant potentials of a compound were also studied. The results favor the potential of SN as an active ingredient to be used in cosmeceutical formulations.</p></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"257 ","pages":"Article 112975"},"PeriodicalIF":3.9,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141539512","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":"Efficacy of photobiomodulation following L-PRF application for recovery of mental nerve neurosensory disturbances caused by genioplasty: A randomized triple-blind clinical trial","authors":"Parsa Behnia ,&nbsp;Bita Rohani ,&nbsp;Seyed Masoud Sajedi ,&nbsp;Parsa Firoozi ,&nbsp;Reza Fekrazad","doi":"10.1016/j.jphotobiol.2024.112973","DOIUrl":"10.1016/j.jphotobiol.2024.112973","url":null,"abstract":"<div><p>The present study assessed the efficacy of photobiomodulation (PBM) following leukocyte-platelet rich fibrin (L-PRF) application for recovery of mental nerve neurosensory disturbances (NSDs) caused by genioplasty. This randomized triple-blind split-mouth clinical trial was conducted on 20 female patients (40 quadrants) requiring genioplasty. In each patient, one random side of the mandible served as the intervention (laser), and the other side as the control group. After genioplasty and L-PRF application, the intervention side underwent GaAIAs diode laser irradiation (880 nm, 500 mW, 15 J/cm², 0.5 cm² spot size, continuous-wave). Each point was laser irradiated for 15 s. Unilateral extraoral PBM was performed at 1, 3, 7, 14, 21, and 28 days, postoperatively. Laser in off mode (sham laser) was used for the control side. A visual analog scale (VAS) was used for general sensitivity, and 2-point discrimination, directional discrimination, pain discrimination, and thermal discrimination tests were used to assess the neurosensory recovery at 2 days, 2 weeks, 4 weeks, and 2 months, postoperatively. Statistical analyses were performed using two-way repeated measures ANOVA, Bonferroni test, and generalized estimating equation (alpha = 0.05). Time had a significant effect on improvement of all sensory variables (<em>P</em> &lt; 0.05). Neurosensory recovery was significantly better in the intervention than the control group at all time points according to the two-point discrimination test (<em>P</em> = 0.0135) and brush test (<em>P</em> = 0.025) results. The interaction effect of time and intervention was not significant on any dependent variable (<em>P</em> &gt; 0.05). Application of L-PRF + PBM resulted in significantly greater sensorineural recovery according to the two-point discrimination and brush test results.</p></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"258 ","pages":"Article 112973"},"PeriodicalIF":3.9,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141579971","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":"Complete photodynamic inactivation of Pseudomonas aeruginosa biofilm with use of potassium iodide and its comparison with enzymatic pretreatment","authors":"Fernanda Alves,&nbsp;Paulo Júnior Tadayoshi Nakada,&nbsp;Maria Júlia de Arruda Mazzotti Marques,&nbsp;Leonardo da Cruz Rea,&nbsp;Anelyse Abreu Cortez,&nbsp;Vanessa de Oliveira Arnoldi Pellegrini,&nbsp;Igor Polikarpov,&nbsp;Cristina Kurachi","doi":"10.1016/j.jphotobiol.2024.112974","DOIUrl":"10.1016/j.jphotobiol.2024.112974","url":null,"abstract":"<div><p><em>Pseudomonas aeruginosa,</em> a gram-negative bacterium, accounts for 7% of all hospital-acquired infections. Despite advances in medicine and antibiotic therapy, <em>P. aeruginosa</em> infection still results in high mortality rates of up to 62% in certain patient groups. This bacteria is also known to form biofilms, that are 10 to 1000 times more resistant to antibiotics compared to their free-floating counterparts. Photodynamic Inactivation (PDI) has been proved to be an effective antimicrobial technique for microbial control. This method involves the incubation of the pathogen with a photosensitizer (PS), then, a light at appropriated wavelength is applied, leading to the production of reactive oxygen species that are toxic to the microbial cells. Studies have focused on strategies to enhance the PDI efficacy, such as a pre-treatment with enzymes to degrade the biofilm matrix and/or an addition of inorganic salts to the PS. The aim of the present study is to evaluate the effectiveness of PDI against <em>P. aeruginosa</em> biofilm in association with the application of the enzymes prior to PDI (enzymatic pre-treatment) or the addition of potassium iodide (KI) to the photosensitizer solution, to increase the inactivation effectiveness of the treatment. First, a range of enzymes and PSs were tested, and the best protocols for combined treatments were selected. The results showed that the use of enzymes as a pre-treatment was effective to reduce the total biomass, however, when associated with PDI, mild bacterial reductions were obtained. Then, the use of KI in association with the PS was evaluated and the results showed that, PDI mediated by methylene blue (MB) in the presence of KI was able to completely eradicate the biofilm. However, when the PDI was performed with curcumin and KI, no additive reduction was observed. In conclusion, out of all strategies evaluated in the present study, the most promising strategy to improve PDI against <em>P. aeruginosa</em> biofilm was the use of KI in association with MB, resulting in eradication with 10⁸ log bacterial inactivation.</p></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"257 ","pages":"Article 112974"},"PeriodicalIF":3.9,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141534583","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":"Exploring the efficacy of laser-assisted in-office tooth bleaching: A study on varied irradiation times and power settings utilizing a diode laser (445 nm)","authors":"Aggeliki Papadopoulou ,&nbsp;Dimitrios Dionysopoulos ,&nbsp;Dimitrios Strakas ,&nbsp;Pantelis Kouros ,&nbsp;Elli Vamvakoudi ,&nbsp;Petroula Tsetseli ,&nbsp;Olga-Elpis Kolokitha ,&nbsp;Kosmas Tolidis","doi":"10.1016/j.jphotobiol.2024.112970","DOIUrl":"https://doi.org/10.1016/j.jphotobiol.2024.112970","url":null,"abstract":"<div><p>The aim of this study was to evaluate the effectiveness of a laser-assisted in-office tooth bleaching treatment, employing a diode laser (445 nm) using different power and time settings. Two hundred human incisors were collected for evaluating tooth color change (ΔΕ₀₀) and whiteness index in dentistry (ΔWI_D) following laser-assisted tooth bleaching treatment. The specimens were distributed into 25 groups (<em>n</em> = 8) according to laser output power (0.5–2 W) and duration of irradiation (10–60 s) that was applied. ΔΕ₀₀ and ΔWI_D were evaluated using a spectrophotometer at three points of time (24 h, 1 week and 1 month after treatments). Three-way ANOVA revealed that power, duration of laser irradiation, and time of measurement after bleaching treatments significantly affected both ΔΕ₀₀ and ΔWI_D <em>(p</em> <em>&lt;</em> <em>0.05)</em>. Furthermore, laser irradiation increased ΔΕ₀₀ and ΔWI_D at all applied powers compared to the control group <em>(p</em> <em>&lt;</em> <em>0.05)</em>, but this increase was dependent on the duration of irradiation. Laser irradiation significantly increased ΔΕ₀₀ when the duration of operation was 50–60 s at 0.5–1 W, while at 1.5–2 W was significantly increased when the duration was 30–60 s. ΔWI_D was significant higher in the laser groups compared to the control group at all powers, except for 0.5 W where it was significant higher when the duration was 50–60 s. The outcomes of the study can help in selecting the suitable power settings and duration of laser exposure to achieve the optimal whitening results while ensuring the safety of the tooth pulp.</p></div>","PeriodicalId":16772,"journal":{"name":"Journal of photochemistry and photobiology. B, Biology","volume":"257 ","pages":"Article 112970"},"PeriodicalIF":3.9,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141487390","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}