• Enemark Jordan posted an update 2 days, 10 hours ago

    Immunotherapy has transformed the field of oncology and patient care. By leveraging the immune system of the host, immunostimulatory compounds exert a durable, personalized response against the patient’s own tumor. Despite the clinical success, the overall response rate from current therapies (e.g., immune checkpoint inhibitors) remains low (∼20%) because tumors develop multiple resistance pathways at molecular, cellular, and microenvironmental levels. Unlike other oncologic therapies, harnessing antitumor immunity requires precise activation of a complex immunological system with multiple levels of regulation over its function. This requires the ability to exert control over immune cells in both intracellular compartments and various extracellular sites, such as the tumor microenvironment, in a spatiotemporally coordinated fashion.The immune system has evolved to sense and respond to nano- and microparticulates (e.g., viruses, bacteria) as foreign pathogens. Through the versatile control of composition, sizeand tumor pathophysiological processes for therapy. These efforts include T cell activation in lymph nodes by coordinating cytosolic delivery of tumor antigens to dendritic cells with simultaneous activation of stimulator of interferon genes (STING), or tumor-targeted delivery of acidotic inhibitors to reprogram the tumor microenvironment and overcome T cell retardation. Each treatment strategy represents a nodal intervention in the cancer-immunity cycle, featuring the versatility of UPS nanoparticles. Overall, this Account aims to highlight nanoimmunology, an emerging cross field that exploits nanotechnology’s unique synergy with immunology through nano-immune-engineering, for advancing cancer immunotherapy.SmI2 was introduced to organic chemistry as a single electron transfer agent in 1977. After ca. 15 years of latency, the scientific community has realized the high potential of this reagent, and its chemistry has started blooming. This versatile reagent has mediated a myriad of new bond formations, cyclizations, and other reactions. Its popularity stems largely from the fact that three different intermediates, radical anions, radicals, and anions, depending on the ligand or additive used, could be obtained. Each of these intermediates could in principle lead to a different product. While these options vastly enrich the repertoire of SmI2, they necessitate a thorough mechanistic understanding, especially concerning how appropriate ligands direct the SmI2 to the desired intermediate. Our first paper on this subject dealt with the reduction of an activated double bond. The results were puzzling, especially the H/D isotope effect, which depended on the order of the reagents addition. This seminal paper was fundamd to directly derive essential information on the binding constants of ligands and substrates to SmI2.In the last few decades, growing numbers of fluorescent probes have been developed to detect intracellular GSH. However, the majority of probes for GSH were irreversible without monitoring the changes of intracellular GSH concentration. Therefore, recently, fluorescent probes for monitoring concentrations of GSH in real-time in living cells have come into being to address this challenge. ACBI1 in vitro This Perspective aimed at the development of reversible probes for GSH was organized by structural features, chemical reactions, and physicochemical properties. The reversible probes designed by a coumarin skeleton as a read-out fluorophore and the Michael addition reaction as a response mechanism accounted for most of the reported reversible probes. The performances of reversible fluorescent probes based on Michael addition could be roughly predicted by fundamental laws of kinetics and thermodynamics in physical chemistry. Essentially, the design principles included a highly reactive site for GSH, a small thermodynamic driving force, a desirable Kd of 1-10 mM, and excellent cell membrane permeability. Prospectively, the development of various mechanisms and fluorophores will be effective measures to enrich the types of reversible probes for GSH.A novel and efficient visible-light-induced decarboxylative cyclization/hydrogenation cascade reaction of α-oxocarboxylic acids and 2-isocyanobiaryls has been developed. Without the need of any external photosensitizer, oxidant, and reductant, this method offers a mild and green approach for the synthesis of diverse alcohols in moderate to good yields. A mechanism indicated that an electron donor-acceptor complex-driven decarboxylation, radical addition/cyclization, and in situ photochemical reduction of ketones to alcohols could be involved in the reaction.Despite the limited direct anthropogenic mercury (Hg) inputs in the circumpolar Arctic, elevated concentrations of methylmercury (MeHg) are accumulated in Arctic marine biota. However, the MeHg production and bioaccumulation pathways in these ecosystems have not been completely unraveled. We measured Hg concentrations and stable isotope ratios of Hg, carbon, and nitrogen in the feathers and blood of geolocator-tracked little auk Alle alle from five Arctic breeding colonies. The wide-range spatial mobility and tissue-specific Hg integration times of this planktivorous seabird allowed the exploration of their spatial (wintering quarters/breeding grounds) and seasonal (nonbreeding/breeding periods) MeHg exposures. An east-to-west increase of head feather Hg concentrations (1.74-3.48 μg·g-1) was accompanied by significant spatial trends of Hg isotope (particularly Δ199Hg 0.96-1.13‰) and carbon isotope (δ13C -20.6 to -19.4‰) ratios. These trends suggest a distinct mixing/proportion of MeHg sources between western North Atlantic and eastern Arctic regions. Higher Δ199Hg values (+0.4‰) in northern colonies indicate an accumulation of more photochemically impacted MeHg, supporting shallow MeHg production and bioaccumulation in high Arctic waters. The combination of seabird tissue isotopic analysis and spatial tracking helps in tracing the MeHg sources at various spatio-temporal scales.Direct irradiation of para-substituted phenols under N2 atmosphere in homogeneous (cyclohexane, acetonitrile, and methanol) and micellar (SDS) solution was investigated by means of time-resolved spectroscopy. After a laser pulse (266 nm), two transient species were formed, viz. the para-substituted phenol radical-cations and the corresponding phenoxy radicals. The radical-cations showed a broad absorption band located between 390 and 460 nm, while the phenoxy radicals showed two characteristic bands centered at 320 nm and 400-410 nm. The deprotonation rate constant of radical-cations (kH) of 105 s-1 and the reaction rate constant of the phenoxy radicals (kR) in the order of 109-1010 M-1·s-1 have been derived. The kH rate constants gave good linear Hammett correlation with positive slope indicating that electron-withdrawing substituents enhance the radical-cation acidity. The binding constants (Kb) of the para-substituted phenols with the surfactant were also measured, and NOESY experiments showed that phenols were located in the hydrophobic core of the micelle.