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Frontiers in Oncology 2023
PubMed: 37546411
DOI: 10.3389/fonc.2023.1248272 -
Chemistry (Weinheim An Der Bergstrasse,... Sep 2023Optical imaging has a wide range of applications in the biomedical field, allowing the visualization of physiological processes and helping in the diagnosis and... (Review)
Review
Optical imaging has a wide range of applications in the biomedical field, allowing the visualization of physiological processes and helping in the diagnosis and treatment of diseases. Unexcited light source imaging technologies, such as chemiluminescence imaging, bioluminescence imaging and afterglow imaging have attracted great attention in recent years because of the absence of excitation light interference in their application and the advantages of high sensitivity and high signal-to-noise ratio. In this review, the latest advances in unexcited light source imaging technology for biomedical applications are highlighted. The design strategies of unexcited light source luminescent probes in improving luminescence brightness, penetration depth, quantum yield and targeting, and their applications in inflammation imaging, tumor imaging, liver and kidney injury imaging and bacterial infection imaging are introduced in detail. The research progress and future prospects of unexcited light source imaging for medical applications are further discussed.
Topics: Humans; Luminescence; Optical Imaging; Liver Neoplasms
PubMed: 37401914
DOI: 10.1002/chem.202301689 -
Drug Delivery and Translational Research Aug 2023Light-responsive biomaterials can be used for the delivery of therapeutic drugs and nucleic acids, where the tunable/precise delivery of payload highlights the potential... (Review)
Review
Light-responsive biomaterials can be used for the delivery of therapeutic drugs and nucleic acids, where the tunable/precise delivery of payload highlights the potential of such biomaterials for treating a variety of conditions. The translucency of eyes and advances of laser technology in ophthalmology make light-responsive delivery of drugs feasible. Importantly, light can be applied in a non-invasive fashion; therefore, light-triggered drug delivery systems have great potential for clinical impact. This review will examine various types of light-responsive polymers and the chemistry that underpins their application as ophthalmic drug delivery systems.
Topics: Biocompatible Materials; Drug Delivery Systems; Polymers
PubMed: 35751001
DOI: 10.1007/s13346-022-01196-5 -
Physical Chemistry Chemical Physics :... Jun 2024Benzoyl-carbazole and its derivatives are considered a platform for exploring processes such as room temperature phosphorescence (RTP) and thermally activated delayed...
Benzoyl-carbazole and its derivatives are considered a platform for exploring processes such as room temperature phosphorescence (RTP) and thermally activated delayed fluorescence (TADF). They have also been reported to exhibit dual emission, but there is a great spectral variability in the relative intensity of the emission bands reported in different studies. To better understand the fundamental photophysical properties, we set to explore BCz and its perfluorinated derivative F5BCz using spectroscopy and quantum chemical simulations. We find that the reported dual fluorescence in solution and in films results from a photochemical process (photo-Fries rearrangement), producing carbazole among other products, explaining the variation in the reported emission spectra. In addition, BCz exhibits solvent dependent TADF, which is explained by the stabilization of the charge transfer S state in polar solvents. F5BCz undergoes an efficient photochemical process (Mallory reaction) from its single state to produce highly fluorescent product c-F5BCz, in 40% isolated yield. This photoreactivity also proceeds in films under ambient conditions, which have significant implications on the applications of BCz-based materials for optoelectronic applications.
PubMed: 38895802
DOI: 10.1039/d4cp01781a -
The Journal of Physical Chemistry... Nov 2023The mercaptomethyl radical (·CHSH) is a higher-energy isomer of the methylthio radical (CHS·) that has been proposed as an important intermediate in atmospheric and...
The mercaptomethyl radical (·CHSH) is a higher-energy isomer of the methylthio radical (CHS·) that has been proposed as an important intermediate in atmospheric and interstellar sulfur chemistry. Herein, we report the spectroscopic identification of ·CHSH during the UV (365 nm) photolysis of CHS· in a solid Ar-matrix at 10 K. Upon subsequent irradiation at 266 nm, the dehydrogenation of ·CHSH to yield CS via the intermediacy of the elusive thioformyl radical (HCS·) has also been observed. The characterization of ·CHSH and HCS· with matrix-isolation IR and UV-vis spectroscopy is supported by C-isotope labeling and quantum chemical calculations at the CCSD(T)-F12a/cc-pVTZ-F12 level using configuration-selective vibrational configuration interaction theory (VCI). The disclosed photochemistry of ·CHSH provides new insight into understanding the chemical evolution of organosulfur molecules in the interstellar medium (ISM).
PubMed: 37962268
DOI: 10.1021/acs.jpclett.3c02526 -
Accounts of Chemical Research Jul 2023ConspectusStereochemical control of excited-state asymmetric photoreactions has been one of the most challenging topics of modern photochemistry. The short-lived...
ConspectusStereochemical control of excited-state asymmetric photoreactions has been one of the most challenging topics of modern photochemistry. The short-lived character of electronically excited photosubstrates and their low activation energy barriers to form both enantiomers are the major obstacles to achieving significant enantioselectivity in excited-state asymmetric photochemistry. Recent research demonstrated that the supramolecular strategy is promising to control the stereochemical outcome of asymmetric photoreaction through relatively strong and long-lasting noncovalent interaction at both ground and excited states. In this methodology, chiral hosts/assemblies provide the chiral environment for photochemically transferring chirality to the complexed photosubstrate in both the ground and the excited states by virtue of relatively strong supramolecular interactions, such as hydrogen bonding, van der Waals, π-π, electrostatic, and hydrophobic interactions. The orientation and conformation of the photosubstrate can be critically manipulated by the supramolecular complexation to ensure the subsequent effective stereoselective photochemical conversion.This Account describes our recent advance in asymmetric photoreactions in supramolecular assemblies. Several chiral photoreactions, including photoisomerization of cycloolefins and photocyclodimerization of anthracene and naphthalene derivatives, have been mediated by various supramolecular hosts, such as cyclodextrin (CD), cucurbituril, pillararene, and chiral polymer. The following advantages of supramolecular asymmetric photochemistry were evidenced: (1) The improvement of stereoselectivity can be enabled by the careful design and fabrication of chiral host molecules. (2) Supramolecular complexation could effectively regulate the orientation and conformation of photosubstrates, thus resulting in novel reaction pathways which create unusual photoproducts that are not achievable through traditional reaction conditions. (3) Asymmetric photoreactions in supramolecular systems showed strong correlations with the external environmental variants, such as temperature, solvent, irradiation wavelength, and pressure, which therefore provide a powerful tool for the regulation of stereoselectivities of excited-state photoreactions. (4) Utilizing supramolecular complexation can dramatically speed up photoreactions, a combination of appropriate photosensitizers/photocatalysts being able to drive catalyzed chiral photoreactions effectively. (5) Photoisomerization in chiral supramolecular systems has been applied to chiroptical molecular devices, which exhibited multiple stimulus-response functions and advanced switching performances. We believe that these concepts, methods, and principles derived therefrom are instructive in designing chiral supramolecular hosts, elucidating the stereodifferentiation mechanisms in the ground and excited states, and analyzing and improving the stereochemical outcomes of a diverse range of supramolecular chiral photoreactions.
PubMed: 37350710
DOI: 10.1021/acs.accounts.3c00234 -
Chemistry (Weinheim An Der Bergstrasse,... Jul 2023Electrochemistry offers a sustainable platform for discovering reactions involving single-electron transfer (SET) that generates highly reactive and synthetically...
Electrochemistry offers a sustainable platform for discovering reactions involving single-electron transfer (SET) that generates highly reactive and synthetically versatile radical species. Compared with photochemistry similarly specializing in SET which requires expensive photocatalysts, electrochemistry employs low-cost electricity to drive the electron flow. Paired electrolysis makes use of both half-reactions, thus obviating the need for sacrificial reactions and maximizing the atom and energy economy. In convergent paired electrolysis, anodic oxidation and cathodic reduction occur simultaneously to generate two intermediates, which are then coupled to furnish the product. It represents a distinctive approach to challenging redox-neutral reactions. However, the gap between the two electrodes makes it hard for a reactive intermediate to come across the other coupling partner. This concept article summarizes recent state-of-the-art advances on radical-based convergent paired electrolysis, which adopted different strategies to overcome the difficulty.
PubMed: 37194485
DOI: 10.1002/chem.202301034 -
The Journal of Physical Chemistry. A Dec 2023The elusive 3-fluoro-2-azirine, NCHCF, has been generated through the stepwise decomposition of the acryloyl azide CHCFC(O)N in an N-matrix at 10 K. The...
The elusive 3-fluoro-2-azirine, NCHCF, has been generated through the stepwise decomposition of the acryloyl azide CHCFC(O)N in an N-matrix at 10 K. The characterization of NCHCF with matrix-isolation IR spectroscopy is supported by N isotope labeling and the calculations with density functional theory (DFT) at the B3LYP/6-311++G(3df,3pd) level of theory. Upon irradiation at 193 nm, NCHCF undergoes ring opening by forming the more stable nitrile isomer CHFCN. In contrast to the photodecomposition reactions, the high-vacuum flash pyrolysis of CHCFC(O)N in the gas phase at 500 °C yields the Curtius rearrangement product CHCFNCO along with secondary fragmentation to the atmospherically relevant fluorocarbonyl radical (FCO) and cyanomethyl radical (CHCN). Calculations on the potential energy profile for the decomposition reactions of CHCFC(O)N demonstrate that the excessive energy, arising from the highly exothermic Curtius rearrangement of the azide, plays a key role in driving further dissociation reactions of CHCFNCO by overcoming the formidable barriers (>50 kcal mol) under the pyrolysis conditions.
PubMed: 38063135
DOI: 10.1021/acs.jpca.3c06076 -
Chem Sep 2023Recently, organic synthesis has seen a renaissance in radical chemistry due to the accessibility of mild methods for radical generation using visible light. While...
Recently, organic synthesis has seen a renaissance in radical chemistry due to the accessibility of mild methods for radical generation using visible light. While renewed interest in synthetic radical chemistry has been driven by the advent of photoredox catalysis, a resurgence of electron donor-acceptor (EDA) photochemistry has also led to many new radical transformations. Similar to photoredox catalysis, EDA photochemistry involves light-promoted single-electron transfer pathways. However, the mechanism of electron transfer in EDA systems is unique wherein the lifetimes of radical intermediates are often shorter due to competitive back-electron transfer. Distinguishing between EDA and photoredox mechanisms can be challenging since they can form identical products. In this perspective, we seek to provide insight on the mechanistic studies which can distinguish between EDA and photoredox manifolds. Additionally, we highlight some key challenges in EDA photochemistry and suggest future goals which could advance the synthetic potential of this field of research.
PubMed: 37873033
DOI: 10.1016/j.chempr.2023.06.013 -
International Journal of Molecular... Aug 2023Over the years, silk fibroin (SF) has gained significant attention in various fields, such as biomedicine, tissue engineering, food processing, photochemistry, and... (Review)
Review
Over the years, silk fibroin (SF) has gained significant attention in various fields, such as biomedicine, tissue engineering, food processing, photochemistry, and biosensing, owing to its remarkable biocompatibility, machinability, and chemical modifiability. The process of obtaining regenerated silk fibroin (RSF) involves degumming, dissolving, dialysis, and centrifugation. RSF can be further fabricated into films, sponges, microspheres, gels, nanofibers, and other forms. It is now understood that the dissolution method selected greatly impacts the molecular weight distribution and structure of RSF, consequently influencing its subsequent processing and application. This study comprehensively explores and summarizes different dissolution methods of SF while examining their effects on the structure and performance of RSF. The findings presented herein aim to provide valuable insights and references for researchers and practitioners interested in utilizing RSF in diverse fields.
Topics: Fibroins; Renal Dialysis; Centrifugation; Food Handling; Microspheres
PubMed: 37685960
DOI: 10.3390/ijms241713153