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Biomedical Optics Express May 2024The therapeutic application of blue light (380 - 500nm) has garnered considerable attention in recent years as it offers a non-invasive approach for the management of...
The therapeutic application of blue light (380 - 500nm) has garnered considerable attention in recent years as it offers a non-invasive approach for the management of prevalent skin conditions including acne vulgaris and atopic dermatitis. These conditions are often characterised by an imbalance in the microbial communities that colonise our skin, termed the skin microbiome. In conditions including acne vulgaris, blue light is thought to address this imbalance through the selective photoexcitation of microbial species expressing wavelength-specific chromophores, differentially affecting skin commensals and thus altering the relative species composition. However, the abundance and diversity of these chromophores across the skin microbiota remains poorly understood. Similarly, devices utilised for studies are often bulky and poorly characterised which if translated to therapy could result in reduced patient compliance. Here, we present a clinically viable micro-LED illumination platform with peak emission 450 nm (17 nm FWHM) and adjustable irradiance output to a maximum 0.55 ± 0.01 W/cm, dependent upon the concentration of titanium dioxide nanoparticles applied to an accompanying flexible light extraction substrate. Utilising spectrometry approaches, we characterised the abundance of prospective blue light chromophores across skin commensal bacteria isolated from healthy volunteers. Of the strains surveyed 62.5% exhibited absorption peaks within the blue light spectrum, evidencing expression of carotenoid pigments (18.8%, 420-483 nm; , spp.), porphyrins (12.5%, 402-413 nm; spp.) and potential flavins (31.2%, 420-425 nm; and spp.). We also present evidence of the capacity of these species to diminish irradiance output when combined with the micro-LED platform and in turn how exposure to low-dose blue light causes shifts in observed absorbance spectra peaks. Collectively these findings highlight a crucial deficit in understanding how microbial chromophores might shape response to blue light and in turn evidence of a micro-LED illumination platform with potential for clinical applications.
PubMed: 38855662
DOI: 10.1364/BOE.522867 -
Spectrochimica Acta. Part A, Molecular... Oct 2024A historical sketch of the MCD (magnetic circular dichroism) spectroscopy is reported in its experimental and theoretical aspects. MCPL (magnetic circularly polarized...
A historical sketch of the MCD (magnetic circular dichroism) spectroscopy is reported in its experimental and theoretical aspects. MCPL (magnetic circularly polarized luminescence) is also considered. The main studies are presented encompassing porphyrinoid systems, aggregates and materials, as well as simple organic molecules useful for the advancement of the interpretation. The MCD of chiral systems is discussed with special attention to new studies of natural products with potential pharmaceutical valence, including Amaryllidaceae alkaloids and related isocarbostyrils. Finally, the vibrational form of MCD, called MVCD, which is recorded in the IR part of the spectrum is also discussed. A final brief note on perspectives is given.
PubMed: 38850611
DOI: 10.1016/j.saa.2024.124583 -
Acta Crystallographica. Section E,... May 2024Title compound , [Ni(CHNO)], a secochlorin nickel complex, was prepared by diol cleavage of a precursor -di-hydroxy-dimethyl-chlorin. Two crystallographically...
Title compound , [Ni(CHNO)], a secochlorin nickel complex, was prepared by diol cleavage of a precursor -di-hydroxy-dimethyl-chlorin. Two crystallographically independent mol-ecules in the structure are related by pseudo-A lattice centering, with mol-ecules differing mainly by a rotation of one of the acetyls and an adjacent phenyl groups. The two mol-ecules have virtually identical conformations characterized by noticeable in-plane deformation in the A mode and a prominent out-of-plane deformation in the B (ruffling) mode. Directional inter-actions between mol-ecules are scarce, limited to just a few C-H⋯O contacts, and inter-molecular inter-actions are mostly dispersive in nature.
PubMed: 38845721
DOI: 10.1107/S2056989024004717 -
Acta Crystallographica. Section E,... May 2024The synthesis, crystallization and characterization of a tri-fluoro-methane-sulfonate salt of 5,10,15,20-tetra-kis-(1-benzyl-pyridin-1-ium-4-yl)-21,23-por-phy-rin, CHN...
The synthesis, crystallization and characterization of a tri-fluoro-methane-sulfonate salt of 5,10,15,20-tetra-kis-(1-benzyl-pyridin-1-ium-4-yl)-21,23-por-phy-rin, CHN ·4CFSO ·4HO, ·OTf, are reported in this work. The reaction between 5,10,15,20-tetra-kis-(pyridin-4-yl)-21,23-porphyrin and benzyl bromide in the presence of 0.1 equiv. of Ca(OH) in CHCN under reflux with an N atmosphere and subsequent treatment with silver tri-fluoro-methane-sulfonate (AgOTf) salt produced a red-brown solution. This reaction mixture was filtered and the solvent was allowed to evaporate at room temperature for 3 d to give ·OTf. Crystal structure determination by single-crystal X-ray diffraction (SCXD) revealed that ·OTf crystallizes in the space group 2/. The asymmetric unit contains half a porphyrin mol-ecule, two tri-fluoro-methane-sulfonate anions and two water mol-ecules of crystallization. The macrocycle of tetra-pyrrole moieties is planar and unexpectedly it has coordinated Ca ions in occupational disorder. This Ca ion has only 10% occupancy (CHCaFNOS). The pyridinium rings bonded to methyl-ene groups from porphyrin are located in two different arrangements in almost orthogonal positions between the plane formed by the porphyrin and the pyridinium rings. The crystal structure features cation⋯π inter-actions between the Ca atom and the π-system of the phenyl ring of neighboring mol-ecules. Both tri-fluoro-methane-sulfonate anions are found at the periphery of , forming hydrogen bonds with water mol-ecules.
PubMed: 38845702
DOI: 10.1107/S205698902400447X -
Neural Regeneration Research Jun 2024PrPSc, a misfolded, aggregation-prone isoform of the cellular prion protein (PrPC), is the infectious prion agent responsible for fatal neurodegenerative diseases of...
PrPSc, a misfolded, aggregation-prone isoform of the cellular prion protein (PrPC), is the infectious prion agent responsible for fatal neurodegenerative diseases of humans and other mammals. PrPSc can adopt different pathogenic conformations (prion strains), which can be resistant to potential drugs, or acquire drug resistance, posing challenges for the development of effective therapies. Since PrPC is the obligate precursor of any prion strain and serves as the mediator of prion neurotoxicity, it represents an attractive therapeutic target for prion diseases. In this minireview, we briefly outline the approaches to target PrPC and discuss our recent identification of Zn(II)-BnPyP, a PrPC-targeting porphyrin with an unprecedented bimodal mechanism of action. We argue that in-depth understanding of the molecular mechanism by which Zn(II)-BnPyP targets PrPC may lead toward the development of a new class of dual mechanism anti-prion compounds.
PubMed: 38845221
DOI: 10.4103/NRR.NRR-D-24-00181 -
Lasers in Medical Science Jun 2024The aim of this study was to compare two types of light irradiation devices for antimicrobial photodynamic therapy (aPDT). A 660-nm light-emitting diode (LED) and a... (Comparative Study)
Comparative Study
The aim of this study was to compare two types of light irradiation devices for antimicrobial photodynamic therapy (aPDT). A 660-nm light-emitting diode (LED) and a 665-nm laser diode (LD) were used for light irradiation, and 0.1 mg/L TONS 504, a cationic chlorin derivative, was used as the photosensitizer. We evaluated the light attenuation along the vertical and horizontal directions, temperature rise following light irradiation, and aPDT efficacy against Staphylococcus aureus under different conditions: TONS 504 only, light irradiation only, and TONS 504 with either LED (30 J/cm) or LD light irradiation (continuous: 30 J/cm; pulsed: 20 J/cm at 2/3 duty cycle, 10 J/cm at 1/3 duty cycle). Both LED and LD light intensities were inversely proportional to the square of the vertical distance from the irradiated area. Along the horizontal distance from the nadir of the light source, the LED light intensity attenuated according to the cosine quadrature law, while the LD light intensity did not attenuate within the measurable range. Following light irradiation, the temperature rise increased as the TONS 504 concentration increased in the order of pulsed LD < continuous LD < LED irradiation. aPDT with light irradiation only or TONS 504 only had no antimicrobial effect, while aPDT with TONS 504 under continuous or pulsed LD light irradiation provided approximately 3 log reduction at 30 J/cm and 20 J/cm and approximately 2 log reduction at 10 J/cm. TONS 504-aPDT under pulsed LD light irradiation provided anti-microbial effect without significant temperature rise.
Topics: Photochemotherapy; Staphylococcus aureus; Photosensitizing Agents; Humans; Lasers, Semiconductor; Porphyrins; Temperature
PubMed: 38839711
DOI: 10.1007/s10103-024-04103-1 -
Food Microbiology Sep 2024To investigate the potential antifungal mechanisms of rhizosphere Actinobacteria against Ceratocystis fimbriata in sweet potato, a comprehensive approach combining...
To investigate the potential antifungal mechanisms of rhizosphere Actinobacteria against Ceratocystis fimbriata in sweet potato, a comprehensive approach combining biochemical analyses and multi-omics techniques was employed in this study. A total of 163 bacterial strains were isolated from the rhizosphere soil of sweet potato. Among them, strain MEPS155, identified as Streptomyces djakartensis, exhibited robust and consistent inhibition of C. fimbriata mycelial growth in in vitro dual culture assays, attributed to both cell-free supernatant and volatile organic compounds. Moreover, strain MEPS155 demonstrated diverse plant growth-promoting attributes, including the production of indole-3-acetic acid, 1-aminocyclopropane-1-carboxylate deaminase, phosphorus solubilization, nitrogen fixation, and enzymatic activities such as cellulase, chitinase, and protease. Notably, strain MEPS155 exhibited efficacy against various sweet potato pathogenic fungi. Following the inoculation of strain MEPS155, a significant reduction (P < 0.05) in malondialdehyde content was observed in sweet potato slices, indicating a potential protective effect. The whole genome of MEPS155 was characterized by a size of 8,030,375 bp, encompassing 7234 coding DNA sequences and 32 secondary metabolite biosynthetic gene clusters. Transcriptomic analysis revealed 1869 differentially expressed genes in the treated group that cultured with C. fimbriata, notably influencing pathways associated with porphyrin metabolism, fatty acid biosynthesis, and biosynthesis of type II polyketide products. These alterations in gene expression are hypothesized to be linked to the production of secondary metabolites contributing to the inhibition of C. fimbriata. Metabolomic analysis identified 1469 potential differently accumulated metabolites (PDAMs) when comparing MEPS155 and the control group. The up-regulated PDAMs were predominantly associated with the biosynthesis of various secondary metabolites, including vanillin, myristic acid, and protocatechuic acid, suggesting potential inhibitory effects on plant pathogenic fungi. Our study underscores the ability of strain S. djakartensis MEPS155 to inhibit C. fimbriata growth through the production of secretory enzymes or secondary metabolites. The findings contribute to a theoretical foundation for future investigations into the role of MEPS155 in postharvest black rot prevention in sweet potato.
Topics: Ipomoea batatas; Streptomyces; Plant Diseases; Ascomycota; Rhizosphere; Soil Microbiology; Antifungal Agents; Multiomics
PubMed: 38839221
DOI: 10.1016/j.fm.2024.104557 -
Plant Physiology and Biochemistry : PPB Jul 2024The albino tea cultivar is one of the most important germplasms for key gene mining and high-quality tea producing. In order to elucidate the chlorophyll-deficient...
The albino tea cultivar is one of the most important germplasms for key gene mining and high-quality tea producing. In order to elucidate the chlorophyll-deficient mechanism of albino cultivar 'Huangjinya' and its offspring, color difference, photosynthetic pigments and the relevant genes' expression of the tender shoots were comprehensively investigated in this study. Among the tested 16 offspring, 5 exhibited albino phenotype in spring and autumn, 3 showed albino phenotype in spring but normal green in autumn, while the rests were all normal green. The shoot of albino offspring had significantly higher lightness and/or yellowness than that of green ones, and possessed dramatically lower photosynthetic pigments and chlorophyll precursor protochlorophyllide (Pchlide), as well as higher chlorophyll a/chlorophyll b but lower chlorophylls/carotenoids in comparison with green ones. Among the tested genes involved in chlorophyll and carotenoid metabolism pathways, expression of the magnesium protoporphyrin IX monomethyl ester cyclase (CRD), 3,8-divinyl chlorophyllide 8-vinyl reductase (DVR), 5-aminolevulinate dehydratase 1 (HEMB1), 1-deoxy-D-xylulose 5-phosphate synthase 1 (DXS1) and 4-hydroxy-3-methylbut-2-enyl diphosphate reductase (ISPH) was remarkably down-regulated in shoots of the albino offspring. Color difference indices of the offspring were significantly correlated with the levels of photosynthetic pigments and Pchlide, and low level of chlorophylls in shoot of albino offspring was mainly due to conversion obstacle from magnesium protoporphyrin Ⅸ (Mg-Proto IX) to Pchlide which might be attributed to down-regulatory expression of CRD and DVR.
Topics: Chlorophyll; Protochlorophyllide; Protoporphyrins; Phenotype; Gene Expression Regulation, Plant; Plant Proteins; Photosynthesis
PubMed: 38838570
DOI: 10.1016/j.plaphy.2024.108778 -
Communications Chemistry Jun 2024The ability to precisely engineer nanostructures underpins a wide range of applications in areas such as electronics, optics, and biomedical sciences. Here we present a...
The ability to precisely engineer nanostructures underpins a wide range of applications in areas such as electronics, optics, and biomedical sciences. Here we present a novel approach for the growth of nanoparticle assemblies that leverages the unique properties of superfluid helium. Unlike viscous solvents at or near room temperature, superfluid helium provides an unperturbed and cold environment in which weak van der Waals interactions between molecular templates and metal atoms become significant and can define the spatial arrangement of nanoparticles. To demonstrate this concept, diol and porphyrin-based molecules are employed as templates to grow gold nanoparticle assemblies in superfluid helium droplets. After soft-landing on a solid surface to remove the helium, transmission electron microscopy (TEM) imaging shows the growth of gold nanoparticles at specific binding sites within the molecular templates where the interaction between gold atoms and the molecular template is at its strongest.
PubMed: 38834741
DOI: 10.1038/s42004-024-01203-5 -
Analytica Chimica Acta Jul 2024Intravascular hemolysis is associated with massive release of hemoglobin and consequently labile heme into the blood, resulting in prothrombotic and proinflammatory...
BACKGROUND
Intravascular hemolysis is associated with massive release of hemoglobin and consequently labile heme into the blood, resulting in prothrombotic and proinflammatory events in patients. Though heme is well-known to participate in these adverse effects, it is not monitored. Instead, haptoglobin and hemoglobin serve as clinical biomarkers. The quantification of labile heme together with hemoglobin, however, should be considered in clinical diagnosis as well, to obtain a complete picture of the hemolytic state in patients. So far, quantification techniques for labile heme were not yet systematically analyzed and compared for their clinical application potential, especially in the presence of hemoglobin.
RESULTS
Two commercial assays (Heme Assay Kit®, Hemin Assay Kit®) and five common approaches (pyridine hemochromogen assay, apo-horseradish peroxidase-based assay, UV/Vis spectroscopy, HPLC, mass spectrometry) were analyzed concerning their linearity, accuracy, and precision, as well as their ability to distinguish between hemoglobin-bound heme and labile heme. Further, techniques for the quantification of hemoglobin (Harboe method, SLS method, Hemastix®) were included to study their selectivity for hemoglobin and potential interference by the presence of labile heme. Both, indirect and direct approaches were suitable for the determination of a wide concentration of heme (∼0.02-45 μM) and hemoglobin (∼0.002-17 μM). A clear distinction between hemoglobin-bound heme and labile heme with one method was not possible. Thus, a novel combined approach is presented and applied to human and porcine plasma samples for the determination of hemoglobin and labile heme.
SIGNIFICANCE
Our results demonstrate the need to develop improved techniques to differentiate labile and protein-bound heme for early detection of intravascular hemolysis. Here, we present a novel strategy by combining two spectroscopic methods, which is most reliable as an easy-to-use tool for the determination of hemoglobin and heme levels in plasma samples for the diagnosis of intravascular hemolysis and in basic biomedical research.
Topics: Hemolysis; Heme; Hemoglobins; Humans; Animals; Swine; Chromatography, High Pressure Liquid
PubMed: 38834280
DOI: 10.1016/j.aca.2024.342766