JACS Au最新文献

Cell surface engineering is a rapidly advancing field, pivotal for understanding cellular physiology and driving innovations in biomedical applications. In this regard, DNA nanotechnology offers unprecedented potential for precisely manipulating and functionalizing cell surfaces by virtue of its inherent programmability and versatile functionalities. Herein, this Perspective provides a comprehensive overview of emerging trends in DNA nanotechnology for cell surface engineering, focusing on key DNA nanostructure-based tools, their roles in regulating cellular physiological processes, and their biomedical applications. We first discuss the strategies for integrating DNA molecules onto cell surfaces, including the attachment of oligonucleotides and the higher-order DNA nanostructure. Second, we summarize the impact of DNA-based surface engineering on various cellular processes, such as membrane protein degradation, signaling transduction, intercellular communication, and the construction of artificial cell membrane components. Third, we highlight the biomedical applications of DNA-engineered cell surfaces, including targeted therapies for cancer and inflammation, as well as applications in cell capture/protection and diagnostic detection. Finally, we address the challenges and future directions in DNA nanotechnology-based cell surface engineering. This Perspective aims to provide valuable insights for the rational design of DNA nanotechnology in cell surface engineering, contributing to the development of precise and personalized medicine.

Cell surface engineering is a rapidly advancing field, pivotal for understanding cellular physiology and driving innovations in biomedical applications. In this regard, DNA nanotechnology offers unprecedented potential for precisely manipulating and functionalizing cell surfaces by virtue of its inherent programmability and versatile functionalities. Herein, this Perspective provides a comprehensive overview of emerging trends in DNA nanotechnology for cell surface engineering, focusing on key DNA nanostructure-based tools, their roles in regulating cellular physiological processes, and their biomedical applications. We first discuss the strategies for integrating DNA molecules onto cell surfaces, including the attachment of oligonucleotides and the higher-order DNA nanostructure. Second, we summarize the impact of DNA-based surface engineering on various cellular processes, such as membrane protein degradation, signaling transduction, intercellular communication, and the construction of artificial cell membrane components. Third, we highlight the biomedical applications of DNA-engineered cell surfaces, including targeted therapies for cancer and inflammation, as well as applications in cell capture/protection and diagnostic detection. Finally, we address the challenges and future directions in DNA nanotechnology-based cell surface engineering. This Perspective aims to provide valuable insights for the rational design of DNA nanotechnology in cell surface engineering, contributing to the development of precise and personalized medicine.

Electrocatalysis, which leverages renewable electricity, has emerged as a cornerstone technology in the transition toward sustainable energy and chemical production. However, traditional electrocatalytic systems often produce mixed, impure products, necessitating costly purification. Solid-state electrolyte (SSE) reactors represent a transformative advancement by enabling the direct production of high-purity chemicals, significantly reducing purification costs and energy consumption. The versatility of SSE reactors extends to applications such as CO₂ capture and tandem reactions, aligning with the green and decentralized production paradigm. This Perspective provides a comprehensive overview of SSE reactors, discussing their principles, design innovations, and applications in producing pure chemicals─such as liquid carbon fuels, hydrogen peroxide, and ammonia─directly from CO₂ and other sources. We further explore the potential of SSE reactors in applications such as CO₂ capture and tandem reactions, highlighting their compatibility with versatile production systems. Finally, we outline future research directions for SSE reactors, underscoring their role in advancing sustainable chemical manufacturing.

The fascinating magnetic and catalytic properties of coordinatively unsaturated 3d metal complexes are a manifestation of their electronic structures, in particular their nearly doubly or triply degenerate orbital ground levels. Here, we propose a criterion to determine the degree of degeneracy of this class of complexes based on their experimentally accessible magnetic anisotropy (parametrized by the electron spin g- and zero-field splitting (ZFS)-tensors). The criterion is derived from a comprehensive spectroscopic and theoretical study in the trigonal planar iron(0) complex, [(IMes)Fe(dvtms)] (IMes = 1,3-di(2',4',6'-trimethylphenyl)imidazol-2-ylidene, dvtms = divinyltetramethyldisiloxane, 1). Accurate ZFS-values (D = +33.54 cm^-1, E/D = 0.09) and g-values (g _∥ = 1.96, g _⊥ = 2.45) of the triplet (S = 1) ground level of complex 1 were determined by complementary THz-EPR spectroscopy and SQUID magnetometry. In-depth effective Hamiltonian (EH) analyses coupled to wave-function-based ab initio calculations show that 1 features a ground level with three energetically close-lying orbital states with a "two-above-one" energy pattern. The observed magnetic anisotropy results from mixing of the two excited electronic states with the ground state by spin-orbit coupling (SOC). EH investigations on 1 and related complexes allowed us to generalize this finding and establish the anisotropy of the g - and ZFS-tensors as spectroscopic markers for assigning two- or three-fold orbital near-degeneracy.

The fascinating magnetic and catalytic properties of coordinatively unsaturated 3d metal complexes are a manifestation of their electronic structures, in particular their nearly doubly or triply degenerate orbital ground levels. Here, we propose a criterion to determine the degree of degeneracy of this class of complexes based on their experimentally accessible magnetic anisotropy (parametrized by the electron spin g- and zero-field splitting (ZFS)-tensors). The criterion is derived from a comprehensive spectroscopic and theoretical study in the trigonal planar iron(0) complex, [(IMes)Fe(dvtms)] (IMes = 1,3-di(2′,4′,6′-trimethylphenyl)imidazol-2-ylidene, dvtms = divinyltetramethyldisiloxane, 1). Accurate ZFS-values (D = +33.54 cm^–1, E/D = 0.09) and g-values (g_∥ = 1.96, g_⊥ = 2.45) of the triplet (S = 1) ground level of complex 1 were determined by complementary THz-EPR spectroscopy and SQUID magnetometry. In-depth effective Hamiltonian (EH) analyses coupled to wave-function-based ab initio calculations show that 1 features a ground level with three energetically close-lying orbital states with a “two-above-one” energy pattern. The observed magnetic anisotropy results from mixing of the two excited electronic states with the ground state by spin–orbit coupling (SOC). EH investigations on 1 and related complexes allowed us to generalize this finding and establish the anisotropy of the g- and ZFS-tensors as spectroscopic markers for assigning two- or three-fold orbital near-degeneracy.

The positron emission tomography (PET) tracer 2-deoxy-2-[¹⁸F]fluoroglucose ([¹⁸F]FDG) is widely used to study diseases where glucose metabolism is dysregulated, including cancer and neurodegenerative disorders. Here we investigate the hypothesis that the 2-position deuterium-enriched analogue 2-deoxy-2-[²H₂]-d-glucose (2-DG-d2) can also map glucose uptake using deuterium metabolic imaging (DMI) without ionizing radiation. To accomplish this, we used a spectrally selective multiband radiofrequency pulse and balanced steady-state free procession (bSSFP) technique, enabling rapid ²H imaging with high specificity and sensitivity to 2-DG-d2. Both in vitro and in vivo validations demonstrated the sequence's ability to suppress endogenous water signal. Mapping of 2-DG-d2 with high spatial resolution was achieved in healthy mouse brains, comparable to what might be obtained using [¹⁸F]FDG PET. The numerous applications of [¹⁸F]FDG PET, as well as recent clinical translation of the natural abundance 2-deoxy-d-glucose (2-DG) parent sugar, suggest that DMI using 2-DG-d2 may be applied to patients in the future.

The Mislow–Braverman–Evans rearrangement, the reversible [2,3]-sigmatropic rearrangement of allylic sulfoxides to allylic sulfenate esters, finds widespread applications in organic synthesis and medicinal chemistry. However, the products of this powerful strategy have primarily been limited to derivatives of allylic alcohols. In contrast, access to structurally similar benzylic alcohols has not yet been established. Described herein is an unprecedented dearomative Mislow–Braverman–Evans rearrangement of aryl sulfoxides to afford benzylic alcohols. A variety of heteroaryl sulfoxides as well as α-naphthyl sulfoxides could be tolerated, and a diverse range of primary, secondary, and tertiary alcohols possessing either alkyl or aryl substituents can be prepared by our protocol with broad functional group tolerance. A patented bioactive molecule could be prepared using our protocol as the key step with exclusive diastereoselectivity, highlighting its potential utility in organic synthesis. Key to the success of the transformation is the dearomative tautomerization to shift the reactive alkene to the exocyclic position enabled by the reversible deprotonation of the benzylic C–H bond, setting the stage for the subsequent [2,3]-sigmatropic rearrangement. Density functional theory (DFT) calculations reveal that protonation of the α-carbon of the sulfoxide is the stereocontrolling step, generating the intermediate that undergoes [2,3]-sigmatropic rearrangement. The full reaction profile is outlined, showing the reversible nature of each step, which causes the observed erosion of the enantiopurity.

Soil-release polymers (SRPs) are important components of fabric care formulations, performing important roles in the cleaning of synthetic fabrics. SRPs modify the surface of textiles and render materials resistant to staining, while offering environmental benefits by enabling effective cleaning using shorter, cooler wash cycles. Most SRPs used in formulations contain petroleum-sourced terephthalic acid, limiting the environmental benefits presented by the use of these key additives. Here, we have prepared SRPs using a selection of pyridine dicarboxylate monomers that can be accessed from biomass and assessed their ability to modify polyester surfaces. Interestingly, a wide range of surface deposition behavior was observed, with soil-release performance significantly impacted by the pyridine dicarboxylate component in use. The performance of polymers containing 2,5-pyridine dicarboxylate units exceeded or was comparable to that of current industry-standard SRPs, while polymers constructed using 2,4- or 2,6-pyridine dicarboxylate units displayed poor performance. Through a range of studies including dynamic light scattering, contact angle analysis, scanning electron microscopy, and molecular modeling we have explored the solution and interfacial behavior of SRPs and propose the observed changes in performance to arise from a combination of differences in solution self-assembly and variation in affinities for polyester surfaces. Our work highlights the potential of using biosourced starting materials in the replacement of petroleum-derived polymers within formulated consumer products and presents a rationale for the design of SRPs.

The Mislow-Braverman-Evans rearrangement, the reversible [2,3]-sigmatropic rearrangement of allylic sulfoxides to allylic sulfenate esters, finds widespread applications in organic synthesis and medicinal chemistry. However, the products of this powerful strategy have primarily been limited to derivatives of allylic alcohols. In contrast, access to structurally similar benzylic alcohols has not yet been established. Described herein is an unprecedented dearomative Mislow-Braverman-Evans rearrangement of aryl sulfoxides to afford benzylic alcohols. A variety of heteroaryl sulfoxides as well as α-naphthyl sulfoxides could be tolerated, and a diverse range of primary, secondary, and tertiary alcohols possessing either alkyl or aryl substituents can be prepared by our protocol with broad functional group tolerance. A patented bioactive molecule could be prepared using our protocol as the key step with exclusive diastereoselectivity, highlighting its potential utility in organic synthesis. Key to the success of the transformation is the dearomative tautomerization to shift the reactive alkene to the exocyclic position enabled by the reversible deprotonation of the benzylic C-H bond, setting the stage for the subsequent [2,3]-sigmatropic rearrangement. Density functional theory (DFT) calculations reveal that protonation of the α-carbon of the sulfoxide is the stereocontrolling step, generating the intermediate that undergoes [2,3]-sigmatropic rearrangement. The full reaction profile is outlined, showing the reversible nature of each step, which causes the observed erosion of the enantiopurity.

The external control of catalytic activity and substrate specificity of enzymes by light has aroused great interest in the fields of biocatalysis and pharmacology. Going beyond, we have attempted to photocontrol enzyme stereoselectivity on the example of phosphotriesterase (PTE), which is capable of hydrolyzing a wide variety of racemic organophosphorus substrates where one of two enantiomers is often highly toxic. To pursue this goal, the photocaged unnatural amino acid o-nitrobenzyl-l-tyrosine (ONBY) was incorporated by genetic code expansion at the large subsite of the active center, together with additional mutations at the small subsite. The stereoselectivities of the resulting PTE variants were tested with the achiral control substrate paraoxon and four different racemic substrates, which contained a p-nitrophenol leaving group in combination with either methyl-phenyl, ethyl-phenyl, methyl-cyclohexyl, or ethyl-cyclohexyl substituents. Comparison of the enantioselectivities (k _cat/K _M for S_p divided by k _cat/K _M for R_p) before and after decaging of ONBY using irradiation revealed the desired photoinduced inversion of enantioselectivity for three of the variants: PTE_I106A-H257ONBY exhibited a 43-fold stereoselectivity switch for the methyl-phenyl substrate, PTE_I106A-F132A-H257ONBY a 184-fold stereoselectivity switch for the methyl-cyclohexyl substrate, and PTE_I106A-F132A-S308A-H257ONBY a 52-fold and a 57-fold stereoselectivity switch for the methyl-cyclohexyl and the ethyl-cyclohexyl substrates. A computational analysis including molecular dynamics simulations and docking showed that a complicated interplay between steric constraints and specific enzyme-substrate interactions is responsible for the observed effects. Our findings significantly broaden the scope of possibilities for the spatiotemporal control of enantioselective transformations using light in biocatalytic systems.