Photochemistry and Photobiology最新文献

Photo-biocatalyst coupled systems offer a promising approach for converting solar energy into valuable fuels. The bio-integrated photocatalytic system sets a research benchmark by utilizing green energy for formic acid production, reducing CO₂ emissions, and enhancing selectivity through bio-enzyme incorporation. This bio-photocatalytic are promising solutions for environmental remediation and energy production. This research reports the synthesis and application of a novel metal-free, nitrogen-enriched graphene composite photocatalyst (N_enGCTPP) for artificial photosynthesis. N_enGCTPP was synthesized by covalently coupling tetraphenyl porphyrin tetracarboxylic acid (TPP) with N-doped graphene via a polycondensation pathway. The photogenerated charge separation then facilitates the regeneration of enzymatically active coenzymes (NADH) for formic acid production catalyzed by formate dehydrogenase. The photocatalyst exhibited remarkable performance in photocatalytic regeneration of the coenzyme NADH from NAD⁺ with a high yield of 41.80%, as well as photocatalytic production of formic acid (HCO₂H) as a solar fuel from CO₂ with a yield of 99.12 μM. This innovative artificial photosynthetic system demonstrates an affordable, highly efficient, and selective approach for converting carbon dioxide into valuable solar fuels and regenerating NADH, addressing environmental concerns and contributing to sustainable energy solutions.

While aging inevitably changes our skin, this complex biological process involves much more than just getting older. As the body's largest organ, the skin constantly safeguards us from harmful environmental pathogens and plays a key role in overall well-being. This study investigated the development and evaluation of a nanogel containing Rosa damascena essential oil for its potential anti-aging properties. The nanogel was prepared from a primary nanoemulsion with a particle size of 86 ± 4 nm. Antioxidant activity, measured using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, was found to be 76% ± 3%. Furthermore, the nanogel demonstrated superior anti-collagenase and anti-elastase activities (60% ± 2% and 51% ± 0.1%, respectively) compared to the essential oil alone. The antibacterial efficacy of the nanogel was tested against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, revealing potent inhibitory effects. To simulate the aging process, rats were subjected to UVB irradiation on both legs 4 days a week before or after treatment. In vivo studies conducted on mice showed that the nanogel effectively reduced the formation of deep wrinkles in treated groups compared to pretreated ones. These findings suggest that the introduced nanogel, with its antioxidant and antimicrobial properties, holds promise as a natural therapeutic approach for wrinkle treatment.

In 1963, Eduardo Lissi and Juan Grotewold started a chemical kinetics and photochemistry group at the School of Sciences at the University of Buenos Aires (Facultad de Ciencias Exactas y Naturales, FCEN, UBA). Political circumstances in Argentina and in Chile were a great determinant of the evolution, dispersion, and re-encounters of the group members. The initial graduate students in the group developed their own research groups working in various Countries and on a variety of projects. We relate the story of the strong interactions with each other of the original group as well as the cooperations and synergy (Intersystem Crossings) of Lissi and Grotewold and of their descendants with other research groups, mainly (but not only) in Latin America. A strong network of partnerships, friendships, and fruitful collaborations between the kineticists, photochemists, and photobiologists in Argentina, Chile and Brazil has evolved from the initial steps in the 1960s.

Dissolving microneedles (DMNs) is a promising technology for transdermal and intradermal drug delivery. However, effective decontamination protocols are necessary to ensure safety and efficacy in clinical applications. The challenge is to use a technique that preserves mechanical properties, does not introduce chemicals, and can decontaminate DMNs without affecting the drug. With its potent antimicrobial properties and minimal residual effects, ozone presents a novel and safe method for decontaminating DMNs. Specifically, the present study assesses ozone's efficacy in decontaminating DMNs loaded with aminolevulic acid, intended for photodynamic therapy in skin cancer treatment. The results showed that it effectively decontaminates E. coli and S. aureus without compromising the polymer properties or promoting drug degradation. Overall, ozone represents an approach that can be adopted to decontaminate DMNs, offering a safer and effective strategy that enhances their potential to translate to clinical application.

Spectral Solar Photosynthetically Photon Flux Density (PPFD) (380-780 nm) reaching the surface in different tree shade conditions and heights has been analyzed in order to better understand the different photosynthetic performance of plants depending on their spatial situation, the canopy density and height with respect to the floor. A comparison between the shadow of nine different trees in a sunny day and the case of a cloudy day in an open space has been studied. A poplar, laurel, amber tree, pine, olive tree, fir tree, cypress, elm tree and magnolia tree have been analyzed. The study has been developed in Valencia (Spain) during July and August 2022. Conditions with higher PPFD received are found to be, apart from those of a sunny day, those for cloudy day, and those for the shade of cypress. The case in which less amount of PPFD is received is that under the shade of olive tree. Both with a spectral maximum in the Blue region. It is also remarkable that the PPFD radiation is proportional to the height of measurement at 10 h, but this relationship changes, and at 13 h the relationship between irradiance received and height of measurement is inversely proportional.

This study investigated the effects of transcranial photobiomodulation (t-PBM) on para-athletes' manual dexterity and intralimbal coordination. Six para-athletes from a Boccia Team participated. t-PBM was administered using a LED helmet with 204 LEDs (660 and 850 nm) emitting 10 mW each, delivering 9 J/cm² per LED during 15-min sessions three times a week. The trial lasted 2 weeks, with baseline, placebo treatment, and post-treatment assessments. Manual dexterity was measured by Box and Ball Test (BBLT), and intralimbal coordination by discrete and continuous horizontal and vertical touch tests. Results showed significant improvements in manual dexterity for the t-PBM group compared to the placebo. Discrete vertical touch tests showed reduced time to perform movements, and continuous vertical touch tests showed increased movement frequency in the t-PBM group. No significant improvements were observed in the placebo group. t-PBM was shown to be a potentially effective treatment, with significant benefits in fine motor skills.

Melanoma is an aggressive cancer that has attracted attention in recent years due to its high mortality rate of 80%. Damage caused by oxidative stress generated by radical (type I reaction) and singlet oxygen, ¹O₂ (type II reaction) oxidative reactions may induce cancer. Thus, studies that aim to unveil the mechanism that drives these oxidative damage processes become relevant. Ergosterol, an analogue of 7-dehydrocholesterol, important in the structure of cell membranes, is widely explored in cancer treatment. However, to date little is known about the impact of different oxidative reactions on these sterols in melanoma treatment, and conflicting results about their effectiveness complicates the understanding of their role in oxidative damage. Our results highlight differences among ergosterol, 7-dehydrocholesterol (7-DHC), and cholesterol in membrane properties when subjected to distinct oxidative reactions. Furthermore, we conducted a comparative study exploring the mechanisms of cell damage by photodynamic treatment in A375 melanoma. Notably, endoperoxides from ergosterol and 7-DHC generated by ¹O₂ showed superior efficacy in reducing the viability of A375 cells compared to their precursor molecules. We also describe a step-by-step process to produce and identify endoperoxides derived from ergosterol and 7-DHC. While further studies are needed, this work provides new insights for understanding cancer cell death induced by different oxidative reactions in the presence of biologically relevant sterols.

Photodynamic therapy (PDT) has shown promise as an adjuvant treatment for malignant pleural mesothelioma when combined with surgical resection. Accurate light dosimetry is critical for treatment efficacy. This study presents an improved method for analyzing light fluence distribution in pleural PDT using a standardized anatomical coordinate system and advanced computational modeling. We utilized an infrared navigation system with an improved treatment delivery wand to track light delivery in real-time. The human chest cavity geometry was reconstructed and the pleura was mapped to a standardized coordinate system, allowing for direct comparisons across patients. Light fluence was calculated using both primary and scattered components, with a novel dual correction method applied to match measured values at detector locations. The standardized approach allowed for statistical analysis of light fluence distribution across anatomical regions in a cohort of 11 patients. Results showed acceptable light fluence uniformity with a standard deviation of 6.6% from the prescribed dose across patients. This comprehensive analysis provides insights for optimizing treatment protocols and lays the groundwork for future studies on singlet oxygen generation and its correlation with treatment outcomes in pleural PDT.

This study investigates the effects of photobiomodulation (PBM) with a 660-nm laser on nerve regeneration and muscle morphometry following median nerve axonotmesis in rats. Sixteen Wistar rats were divided into a control group and laser-treated group, with the latter receiving 10 applications of PBM (660 nm; 20 mW; 10 J/cm²; 0.4 J; and 20 s) over 2 weeks. Functional analysis was performed using the grasping test, which measures the grip strength of the forelimb digits to evaluate motor function of the median nerve. Morphometric analyses were conducted on the median nerve, flexor digitorum (FD) muscle, and flexor carpi radialis (FCR) muscle. PBM led to functional improvement, with significant differences observed on the 21st day post-injury. However, no significant differences between groups were found in nerve morphometry. Morphometric analysis of the FD muscle revealed significant improvements in the PBM group, but with no significant differences regarding the FCR muscle. These findings suggest that 660-nm laser with the parameters used produced functional improvement as well as significant improvements in the morphometry of the FD muscle, but did not have significant effects on the morphometry of the FCR muscle or nerve regeneration.

Photodynamic inactivation (PDI) combines the use of photosensitizers with visible light to produce reactive oxygen species that effectively eliminate pathogens. To investigate the impact of near- infrared therapy (NIRT) on heme biosynthesis and permeability of the pro-photosensitizers 5-aminolevulinic acid (ALA) and Hexyl-ALA (H-ALA) through biofilms, we applied sub-lethal conditions for both NIRT and PDI to maintain intact bacterial viability. During NIRT, the temperature remained below 37°C, permitting rapid heating (ΔT = 11°C) without causing thermal damage. NIRT potentiated the bactericidal effects of ALA-PDI by 3 logs in Staphylococcus aureus RN6390 biofilms and 4 logs in ST5-SCCmecI biofilms. With H-ALA-PDI, reductions of 4 and 6 logs, respectively, were observed. In the case of ALA, this enhancement was partly due to increased porphyrin synthesis, a result not replicated by simple heating. For H-ALA, the enhanced effect of PDI was likely due to biofilm or bacterial membrane destabilization caused by NIRT and H-ALA. Unlike biofilms, applying the same ALA-PDI conditions, the treatment was effective in planktonic S. aureus RN6390 cultures, reducing the bacteria by 3 logs, with no additional benefit from NIRT, suggesting that NIRT primarily aids in penetrating the biofilm matrix rather than the bacterial cells. Confocal fluorescence microscopy confirmed that NIRT-treated biofilms exposed to ALA exhibited higher porphyrin fluorescence than untreated biofilms. These findings support the use of NIRT in enhancing the effectiveness of PDI against bacterial biofilms.