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Journal of Hazardous Materials Feb 2020Bacterial infection is a serious problem threatening human health. The chitosan (CS)-modified MoS coating loaded with silver nanoparticles (Ag NPs) was designed on the...
Bacterial infection is a serious problem threatening human health. The chitosan (CS)-modified MoS coating loaded with silver nanoparticles (Ag NPs) was designed on the surface of titanium (Ti) to kill bacteria rapidly and efficiently under 660 nm visible light. Ag/MoS exhibited high photocatalytic activity due to the rapid transfer of photo-inspired electrons from MoS to Ag NPs, resulting in higher yields of radical oxygen species (ROS) to kill bacteria. The covering of CS made the composite coating positively charged to further enhance the antibacterial property of the coating. In addition, CS/Ag/MoS-Ti also showed a certain photothermal effect. in vitro results showed that the antibacterial efficiency of the coating on Staphylococcus aureus and Escherichia coli was 98.66% and 99.77% respectively, when the coating was irradiated by 660 nm visible light for 20 min. Cell culture tests showed that CS/Ag/MoS-Ti had no adverse effects on cell growth. Hence, this surface system will be a very promising strategy for eliminating bacterial infection on biomedical device and implants safely and effectively within a short time.
Topics: Anti-Bacterial Agents; Chitosan; Disulfides; Escherichia coli; Light; Microbial Sensitivity Tests; Molybdenum; Photochemistry; Silver; Staphylococcus aureus
PubMed: 31518801
DOI: 10.1016/j.jhazmat.2019.121122 -
Advanced Drug Delivery Reviews May 2023Ocular drug delivery and therapy systems have been extensively investigated with various methods including direct injections, eye drops and contact lenses. Nowadays,... (Review)
Review
Ocular drug delivery and therapy systems have been extensively investigated with various methods including direct injections, eye drops and contact lenses. Nowadays, smart contact lens systems are attracting a lot of attention for ocular drug delivery and therapy due to their minimally invasive or non-invasive characteristics, highly enhanced drug permeation, high bioavailability, and on-demand drug delivery. Furthermore, smart contact lens systems can be used for direct light delivery into the eyes for biophotonic therapy replacing the use of drugs. Here, we review smart contact lens systems which can be classified into two groups of drug-eluting contact lens and ocular device contact lens. More specifically, this review covers smart contact lens systems with nanocomposite-laden systems, polymeric film-incorporated systems, micro and nanostructure systems, iontophoretic systems, electrochemical systems, and phototherapy systems for ocular drug delivery and therapy. After that, we discuss the future opportunities, challenges and perspectives of smart contact lens systems for ocular drug delivery and therapy.
Topics: Contact Lenses; Drug Delivery Systems; Nanoparticles; Nanocomposites; Iontophoresis; Electrochemistry; Photochemistry; Humans; Animals
PubMed: 37004938
DOI: 10.1016/j.addr.2023.114817 -
The Journal of Physical Chemistry. B Nov 2023Microbial rhodopsins are photoreceptive membrane proteins of microorganisms that express diverse photobiological functions. All--retinylidene Schiff base, the so-called... (Review)
Review
Microbial rhodopsins are photoreceptive membrane proteins of microorganisms that express diverse photobiological functions. All--retinylidene Schiff base, the so-called all--retinal, is a chromophore of microbial rhodopsins, which captures photons. It isomerizes into the 13- form upon photoexcitation. Isomerization of retinal leads to sequential conformational changes in the protein, giving rise to active states that exhibit biological functions. Despite the rapidly expanding diversity of microbial rhodopsin functions, the photochemical behaviors of retinal were considered to be common among them. However, the retinal of many recently discovered rhodopsins was found to exhibit new photochemical characteristics, such as highly red-shifted absorption, isomerization to 7- and 11- forms, and energy transfer from a secondary carotenoid chromophore to the retinal, which is markedly different from that established in canonical microbial rhodopsins. Here, I review new aspects of retinal found in novel microbial rhodopsins and highlight the emerging problems that need to be addressed to understand noncanonical retinal photochemistry.
Topics: Rhodopsins, Microbial; Rhodopsin; Photochemistry; Retina; Carotenoids
PubMed: 37853716
DOI: 10.1021/acs.jpcb.3c05467 -
Biomedical Materials (Bristol, England) Feb 2021Optical imaging is a facile tool for visualizing biological processes and disease progression, but its image quality is largely limited by light-induced autofluorescence... (Review)
Review
Optical imaging is a facile tool for visualizing biological processes and disease progression, but its image quality is largely limited by light-induced autofluorescence or background signals. To overcome this issue, low-background optical-imaging techniques including chemiluminescence imaging, afterglow imaging and photoacoustic imaging have been developed, based on their unique working mechanisms, which are: the detection of light emissions from chemical reactions, the cessation of light excitation before signal collection, and the detection of ultrasonic signals instead of light signals, respectively. Stimuli-responsive probes are highly desirable for improved imaging results since they can significantly reduce surrounding interference signals. Reactive oxygen species (ROS), which are closely implicated in a series of diseases such as cancer and inflammation, are frequently employed as initiators for responsive agents to selectively change the imaging signal. Thus, ROS-responsive agents incorporated into low-background imaging techniques can achieve a more promising imaging quality. In this review, recent advances in ROS-responsive probes for low-background optical-imaging techniques are summarized. Moreover, the approaches to improving the sensitivity of probes and tissue penetration depth are discussed in detail. In particular, we highlight the reaction mechanisms between the probes and ROS, revealing the potential for low-background optical imaging.
Topics: Acoustics; Adamantane; Animals; Disease Progression; Fluorescent Dyes; Humans; Luminescence; Luminol; Mice; Neoplasms; Optical Imaging; Photochemistry; Photosensitizing Agents; Reactive Oxygen Species; Ultrasonic Therapy; Ultrasonics
PubMed: 33142272
DOI: 10.1088/1748-605X/abc745 -
Photochemistry and Photobiology Jan 2023Interest in Criegee intermediates (CIs), often termed carbonyl oxides, and their role in tropospheric chemistry has grown massively since the demonstration of... (Review)
Review
Interest in Criegee intermediates (CIs), often termed carbonyl oxides, and their role in tropospheric chemistry has grown massively since the demonstration of laboratory-based routes to their formation and characterization in the gas phase. This article reviews current knowledge regarding the electronic spectroscopy of atmospherically relevant CIs like CH OO, CH CHOO, (CH ) COO and larger CIs like methyl vinyl ketone oxide and methacrolein oxide that are formed in the ozonolysis of isoprene, and of selected conjugated carbene-derived CIs of interest in the synthetic chemistry community. Of the aforementioned atmospherically relevant CIs, all except CH OO and (CH ) COO exist in different conformers which, under tropospheric conditions, can display strikingly different thermal loss rates via unimolecular and bimolecular processes. Calculated photolysis rates based on their absorption properties suggest that solar photolysis will rarely be a significant contributor to the total loss rate for any CI under tropospheric conditions. Nonetheless, there is ever-growing interest in the absorption cross sections and primary photochemistry of CIs following excitation to the strongly absorbing ππ* state, and how this varies with CI, with conformer and with excitation wavelength. The later part of this review surveys the photochemical data reported to date, including a range of studies that demonstrate prompt photo-induced fission of the terminal O-O bond, and speculates about possible alternate decay processes that could occur following non-adiabatic coupling to, and dissociation from, highly internally excited levels of the electronic ground state of a CI.
Topics: Spectrum Analysis; Oxides; Photochemistry
PubMed: 35713380
DOI: 10.1111/php.13665 -
Photochemistry and Photobiology Nov 2021Sulfoximines are popular scaffolds in drug discovery due to their hydrogen bonding properties and chemical stability. In recent years, the role of reactive intermediates...
Sulfoximines are popular scaffolds in drug discovery due to their hydrogen bonding properties and chemical stability. In recent years, the role of reactive intermediates such as nitrenes has been studied in the synthesis and degradation of sulfoximines. In this work, the photochemistry of N-phenyl dibenzothiophene sulfoximine [5-(phenylimino)-5H-5λ -dibenzo[b,d]thiophene S-oxide] was analyzed. The structure resembles a combination of N-phenyl iminodibenzothiophene and dibenzothiophene S-oxide, which generate nitrene and O( P) upon UV-A irradiation, respectively. The photochemistry of N-phenyl dibenzothiophene sulfoximine was explored by monitoring the formation of azobenzene, a photoproduct of triplet nitrene, using direct irradiation and sensitized experiments. The reactivity profile was further studied through direct irradiation experiments in the presence of diethylamine (DEA) as a nucleophile. The studies demonstrated that N-phenyl dibenzothiophene sulfoximine underwent S-N photocleavage to release singlet phenyl nitrene which formed a mixture of azepines in the presence of DEA and generated moderate amounts of azobenzene in the absence of DEA to indicate formation of triplet phenyl nitrene.
Topics: Molecular Structure; Oxides; Photochemistry; Thiophenes
PubMed: 34022069
DOI: 10.1111/php.13456 -
Photochemical & Photobiological... May 2022Although reported several decades ago, 3,3',5,5'-tetramethoxybenzoin esters have not been used as a common photolabile protecting group, contrary to their unsymmetrical...
Although reported several decades ago, 3,3',5,5'-tetramethoxybenzoin esters have not been used as a common photolabile protecting group, contrary to their unsymmetrical 3',5'-dimethoxybenzoin analogues. While the properties of the latter are superior, their tedious synthesis and chemical instability represent a drawback. In this article, we describe a reliable synthetic access to the symmetrical tetramethoxybenzoin derivatives, and show that their photochemical behaviour remain interesting, in particular chromatically orthogonality with respect to nitroveratryl esters.
Topics: Esters; Photochemistry; Photolysis
PubMed: 35028893
DOI: 10.1007/s43630-021-00150-7 -
Methods (San Diego, Calif.) Sep 2019
Topics: Biosensing Techniques; Cell Membrane Permeability; Coloring Agents; Electrochemistry; Fluorescent Dyes; HeLa Cells; Humans; Hydrogen-Ion Concentration; Ions; Luminescence; Metals; Microscopy, Fluorescence; Nanotechnology; Organic Chemicals; Photochemistry; Quantum Dots
PubMed: 31521733
DOI: 10.1016/j.ymeth.2019.09.010 -
Angewandte Chemie (International Ed. in... Jan 2021Amino acids (AAs) are key structural motifs with widespread applications in organic synthesis, biochemistry, and material sciences. Recently, with the development of... (Review)
Review
Amino acids (AAs) are key structural motifs with widespread applications in organic synthesis, biochemistry, and material sciences. Recently, with the development of milder and more versatile radical-based procedures, the use of strategies relying on radical chemistry for the synthesis and modification of AAs has gained increased attention, as they allow rapid access to libraries of novel unnatural AAs containing a wide range of structural motifs. In this Minireview, we provide a broad overview of the advancements made in this field during the last decade, focusing on methods for the de novo synthesis of α-, β-, and γ-AAs, as well as for the selective derivatisation of canonical and non-canonical α-AAs.
Topics: Amino Acids; Humans; Peptides; Photochemistry
PubMed: 32841470
DOI: 10.1002/anie.202010157 -
Chimia Oct 2021Thomas Bally has acquired international recognition for his work on the photochemistry of reactive intermediates, which include radical ions. Here, we present a brief...
Thomas Bally has acquired international recognition for his work on the photochemistry of reactive intermediates, which include radical ions. Here, we present a brief overview of our investigations of the excited-state dynamics of radical ions in liquids at room temperature, which are still poorly documented. A better understanding of these dynamics is most relevant, as open-shell ions in the excited state are being increasingly used in redox photochemistry and have been proposed to play a key role in highly exergonic photoinduced electron transfer reactions.
Topics: Electron Transport; Electrons; Ions; Oxidation-Reduction; Photochemistry
PubMed: 34728012
DOI: 10.2533/chimia.2021.856