Photochemical & Photobiological Sciences最新文献

Phthalides represent a notable category of secondary metabolites that are prevalent in various plant species, certain fungi, and liverworts. The significant pharmacological properties of these compounds have led to the synthesis of a novel phthalide derivative. The current study focuses on investigating the binding interactions of a newly synthesized 3-substituted phthalide derivative, specifically 3-((4-chloro-6-methyl pyrimidine-2-yl)amino) isobenzofuran-1(3H)-one (Z11), with double-stranded deoxyribonucleic acid (dsDNA). Research in the pharmaceutical and biological fields aimed at developing more potent DNA-binding agents must take into account the mechanisms by which these newly synthesized compounds interact with DNA. This investigation seeks to explore the binding dynamics between dsDNA and our compound through a variety of analytical techniques, such as electrochemistry, UV spectroscopy, fluorescence spectroscopy, and thermal denaturation. The binding constant (K_b) of Z11 with DNA was determined using both spectroscopic and voltammetric approaches. The research revealed that Z11 employs a groove binding mechanism to associate with dsDNA. To further explore the interactions between Z11 and dsDNA, the study utilized density functional theory (DFT) calculations, molecular docking, and molecular dynamics simulations. These analyses aimed to ascertain the potential for a stable complex formation between Z11 and dsDNA. The results indicate that Z11 is situated within the minor groove of the dsDNA, demonstrating the ability to establish a stable complex. Furthermore, the findings imply that both π-alkyl interactions and hydrogen bonding play significant roles in the stabilization of this complex.

Diurnal preference to eveningness might predispose to depression. There is preliminary evidence of infrared-A (IR-A) induced whole-body hyperthermia (WBH) in the treatment of depression. In this exploratory study with 19 adults, we investigated the effects of a 20-min exposure of water-filtered IR-A (wIRA) to the skin of back and buttock area, without inducing WBH, on mood and assessed the outcome by diurnal preference (#R19047, approval on 7 May 2019). The skin received irradiation with an integrated power of 102.4 W in the wavelength region of 550-1350 nm and a total dose of 123 kJ over the total area of 0.0483 m². The diurnal preference was assessed with a 6-item version of the Morningness-Eveningness Questionnaire (mMEQ). The 40-item Profile of Mood States (POMS) questionnaire was used to assess total mood disturbance (TMD). Core temperature was measured 30 min before, during and 30 min after the irradiation. Skin surface temperature was measured on baseline and every two minutes during the irradiation. The TMD improved immediately after the exposure, and this positive effect lasted for 24 h (p = 0.001) as well as for 2 weeks (p = 0.02). Concerning the diurnal preference, the positive effect on mood was immediate and lasted for 24 h in evening types (p = 0.02) and for 2 weeks in morning types (p = 0.04). During the exposure, core body temperature was constantly lower in morning types compared to evening types. This study gives us new information on the effects of near-infrared radiation, without inducing WBH, through the skin on mood.

Herein, we establish the release of aliphatic acids in water upon excitation of 7-diethylaminothio-4-coumarinyl derivatives encapsulated within the organic host octa acid (OA). The 7-diethylaminothio-4-coumarinyl skeleton, employed here as the trigger, photoreleases caged molecules from the excited triplet state, in contrast to its carbonyl analogue, where the same reaction is known to occur from the excited singlet state. Encapsulation in OA solubilizes molecules in water that are otherwise water-insoluble, and retains the used trigger within itself following the release of the aliphatic acid. Such supramolecular characteristics usher in new features to the photorelease methodology. The thiocarbonyl chromophore extends the absorption of coumarinyl trigger to visible range while enhancing the intersystem crossing (ISC) to the triplet state, making it the reactive state. Despite the non-polar environment within the OA capsules the photocleavage occurs in a heterolytic fashion to release the conjugate base and the used trigger as triplet carbocation in an adiabatic process. Interestingly, the triplet carbocation crosses to the ground singlet surface (closed shell singlet carbocation) with the help of water molecules, possibly aided by C = S chromophore. Utilizing the known excited state dynamics of related thiocoumarinyl and coumarinyl systems, we have identified a few of the important mechanistic features of the photorelease process of 7-diethylaminothio-4-coumarinyl derivatives. Ultrafast excited state dynamic studies and quantum chemical calculations planned should help us better understand the photorelease process so as to effectively exploit the proposed system for potential applications.

Ultraviolet A (UVA) radiation is the major fraction of UV radiation reaching the Earth's surface. Its harmful effects on microorganisms, due mainly to oxidative damage, have been exploited for development of natural solar and commercial UVA-based disinfection methods. In this work, the global transcriptional response of Pseudomonas aeruginosa exposed to ultraviolet A (UVA) radiation was analyzed. To conduct this study, we analyzed the whole transcriptome of the PAO1 strain grown to logarithmic phase under sublethal doses of UVA or in the dark. We found that a total of 298 genes responded to UVA with a change of at least two-fold (5.36% of the total P. aeruginosa genome), and showed equal amount of induced and repressed genes. An important fraction of the induced genes were involved in the response to DNA damage and included induction of SOS, prophage and pyocins genes. The results presented in this study suggest that one of the main UVA targets are proteins carrying [Fe-S] clusters since several genes involved in the processes of synthesis, trafficking and assembly of these structures were upregulated. The management of intracellular iron levels also seems to be a robust response to this stress factor. The strong induction of genes involved in denitrification suggest that this pathway and/or reactive nitrogen species such as nitric oxide could have a role in the response to this radiation. Regarding the down-regulated genes, we found many involved in the biosynthesis of PQS, a quorum-sensing signal molecule with a possible role as endogenous photosensitizer.

Hidradenitis suppurativa is a chronic skin disorder characterized by painful inflammatory nodules and abscesses, significantly impacting patients' quality of life. Current treatment strategies, including topical antibiotics, often yield limited efficacy and pose risks of antibiotic resistance. Photodynamic therapy has emerged as a potential option, with RLP068/Cl (ELKOFAST®, non-sterile formulation) showing promising efficacy due to its broad-spectrum bactericidal activity. We conducted a pilot study assessing the therapeutic response to photodynamic therapy with RLP068/Cl versus topical clindamycin gel in patients affected by hidradenitis suppurativa of Hurley score I, II, and III. Results revealed higher efficacy of photodynamic therapy in combination with RLP068/Cl, particularly in mild cases. Its efficacy remains reliable even in more severe cases when combined with adalimumab. The observed faster lesion improvement and pain relief were ascribed to the bactericidal effects of RLP068/Cl against Gram⁺ and Gram^- bacteria. Furthermore, photoactivated RLP068/Cl was well tolerated with no adverse events reported. Therefore, photodynamic therapy following RLP068/Cl application represents a novel therapeutic option for hidradenitis suppurativa with potential implications for antibiotic stewardship in dermatology.

Due to the widespread use and incorrect handling of plastics, we need to find a practical and effective way to eliminate plastic waste from the environment. Different metal-doped nickel oxide (DMD-NiO) nanoparticles (NPs) were synthesized using a sol-gel technique and were used to degrade low-density polyethylene (LDPE) microplastic (MP) films when exposed to sunlight. The optical and structural properties of sol-gel method synthesized materials were investigated using a variety of characterization methods (Fourier transform infrared (FT-IR), UV-vis diffuse reflectance spectroscopy (UV-vis DRS), X-ray diffractometer (XRD) analysis, X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HR-TEM), scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis, and thermogravimetric analysis (TGA). Degradation study results suggest that the photocatalytic activity of DMD-NiO-LDPE nanocomposites (NCs) films was greater than that of pure LDPE and undoped NiO-LDPE films. Because of their increased optical absorption and efficient suppression of photo-produced charge carriers' recombination, the DMD-NiO NPs showed higher photocatalytic degradation of LDPE films. Thus, LDPE films with 2% wt Fe-NiO (iron-doped nickel oxide) nanomaterials showed a degradation of around 38.16% among DMD-NiO-LDPE NCs films under visible light over a short period of 30 days (240 h). The formation of carbonyl groups in the degradation product of LDPE was confirmed by Fourier transform infrared (FT-IR) analysis. When compared to the original LDPE film, the Fe-NiO-LDPE NCs films showed a significant decrease in crystallinity and carbonyl indexes, as much as 8.4% lower. The current project proposes the development of eco-friendly photocatalysts using a sol-gel technique for combating MP pollution in the environment.

Perovskite quantum dots (pQDs) have gathered a lot of attention because of their outstanding optoelectronic properties. Photoswitchable pQDs have the potential for application in single particle optical memories and bio-imaging. Hybrids of photochromic diarylethenes (DAE) and pQDs show a luminescence photoswitching property, however, the cycle stability in such systems is low because of photoinduced electron transfer (PET) from pQDs to DAE. In this study, various hybrids of DAEs and pQDs with different spacer lengths between the pQD donors and DAE acceptors were synthesized and their stability towards multiple cycles of luminescence photoswitching was evaluated. It was found that the electron transfer pathway can be blocked and very stable switchable hybrids can be produced when the distance between the donors and acceptors was long enough. Furthermore, the effect of softness of the basic ligands and the synthesis method of the pQDs on the cycle stability of the hybrids were investigated. The findings of this study suggest that the photoswitching stability can be improved in hybrid systems by proper molecular design of the photochromic molecule.

Far-infrared (FIR) ray, an invisible electromagnetic radiation with a wavelength of 3‒1000 μm, elicits various biological effects. Excessive proliferation of human upper airway epithelial cells (HUAEpCs) contributes to the development and exacerbation of nasal narrowing diseases, including nasal polyposis and chronic rhinosinusitis with nasal polyps (CRSwNP). Here, we investigated the molecular mechanisms through which FIR irradiation inhibits the proliferation of HUAEpCs. FIR irradiation significantly inhibited the proliferation of NCI-H292 cells without alteration in cell viability. The anti-proliferative effect of FIR radiation was accompanied by decreased phosphorylation of p70S6K at Thr³⁸⁹ (p-p70S6K-Thr³⁸⁹), without changes in the phosphorylation of mammalian target of rapamycin and adenosine monophosphate-activated protein kinase (AMPK). Overexpression of p70S6K-T389E mutant gene, not dominant negative-AMPKα1 gene, significantly reversed FIR irradiation-inhibited p-p70S6K-Thr³⁸⁹ and cell proliferation. Cotreatment with okadaic acid or knockdown of protein phosphatase 2A catalytic subunit (PP2Ac) gene expression significantly reversed FIR irradiation-decreased p-p70S6K-Thr³⁸⁹ and cell proliferation. FIR irradiation remarkably promoted the physical association of p70S6K and PP2Ac without change in total PP2Ac expression. Hyperthermal stimulus (39 °C) did not alter p-p70S6K-Thr³⁸⁹ and cell proliferation. In line with NCI-H292 cell results, FIR irradiation, not hyperthermal stimulus, significantly decreased p-p70S6K-Thr³⁸⁹ and cell proliferation in primary human nasal turbinate and polyp epithelial cells. These results demonstrated that FIR irradiation decreased the proliferation of HUAEpCs through PP2A-mediated inhibition of p70S6K phosphorylation, independent of its hyperthermal effect. Our data suggest that FIR therapy can be used to treat upper airway narrowing epithelial hyperplastic diseases, including nasal polyposis and CRSwNP.

Cefadroxil is a widely used antibiotic with a low elimination efficiency in wastewater treatments plants, so it represents a contaminants of emerging concern that should be removed. The photosensitization process that involves natural pigments and visible sunlight can be offered as an environmentally friendly alternative to be considered for Cefadroxil degradation. In this investigation, we carried out a mechanistic and kinetic approach to Cefadroxil photodegradation sensitized by Riboflavin and Humic Acid, in individual and combined processes. Our experiments indicate that Cefadroxil is able to interact with the excited states of Riboflavin as well as with the photogenerated reactive oxygen species, with an important contribution of singlet oxygen. The antibiotic was less sensitive to the photodegradation in the presence of Humic Acids and in the mixture of Riboflavin and Humic Acids. Self-sensitization processes and internal filter effects are proposed as possible explanations for the observed phenomenon. The reaction between Cefadroxil and singlet oxygen showed a dependence with the pH of the medium, the photodegradation kinetic constants are greater at alkaline pH compared to neutral pH. The reaction is favored when the anionic species of the antibiotic is present. Microbiological tests on S. aureus indicated that the antibiotic reduce its antimicrobial activity as a consequence of the photooxidative process mediated by singlet oxygen. We believe that the results are relevant since, the sensitized photodegradation process could lead to the oxidation of Cefadroxil and to the progressive loss of its antimicrobial function, this fact could contribute to the decrease in the generation of bacterial multi-resistance to antibiotics in the environment.

Sunscreens are mainly characterized by their sun-protection factor (SPF), which is measured according to the in vivo gold standard ISO 24444. Although the SPF concept is simple, SPF values are difficult to measure, due to the rather high variability caused by the complex interaction of light and skin. For half a century, there have been attempts to correlate the costly and ethically controversial in vivo procedure with a non-invasive (in vitro) method. After decades of development, alternative non-invasive SPF methods are expected to become available as ISO standards in early 2025. In particular, sunscreen manufacturers who use zinc oxide (ZnO) in higher concentrations (conc.) (10-25%) in their formulations, are concerned that these new in vitro methods would not confirm the SPF-values on their labels that have been determined in vivo, according to ISO 24444. This brief review reveals that sunscreen formulations with high conc. of ZnO often yield SPF_{in vitro} values that are lower than the SPF_{in vivo} values. This can be explained by the fact that in vitro methods have been developed for conventional emulsions products with organic UV filters, but not for highly concentrated ZnO-alone sunscreens. Fortunately, there seems to be a fix for this problem. There is a difference in density between ordinary emulsions with organic filters (density of the residual oil phase ~ 1.0 g/ml) and highly concentrated ZnO-alone formulations (~ 1.3-1.7 g/ml). As the application of current standards is weight-based, this makes the film on the PMMA plate much thinner, which is likely to lead to lower SPF_{in vitro} values. Preliminary experiments show that using the same volume on the PMMA plates instead of the same weight as organic UV filters gives a much better correlation between in vitro and in vivo SPF results. A recent evaluation of three samples of highly concentrated ZnO sunscreens by the Dutch NVWA seems to confirm these findings. Further experimental evidence is required to fully understand this phenomenon and to adapt the in vitro method for higher conc. ZnO formulations accordingly.