Triethylamine-mediated protonation-deprotonation unlocks dual-drug self assembly to suppress breast cancer progression and metastasis.

Carrier-free nanomedicines exhibited significant potential in elevating drug efficacy and safety for tumor management, yet their self assembly typically relied on chemical modifications of drugs or the incorporation of surfactants, thereby compromising the drug's inherent pharmacological activity. To address this challenge, we proposed a triethylamine (TEA)-mediated protonation-deprotonation strategy that enabled the adjustable-proportion self assembly of dual drugs without chemical modification, achieving nearly 100% drug loading capacity. Molecular dynamic simulations, supported by experiment evidence, elucidated the underlying self-assembly mechanism.

A planar-sheet nongraphitic zero-bandgap sp carbon phase made by the low-temperature reaction of γ-graphyne.

The highest sheet symmetry form of graphyne, with one triple bond between each neighboring hexagon in graphene, irreversibly transforms exothermically at ambient pressure and low temperatures into a nongraphitic, planar-sheet, zero-bandgap phase consisting of intrasheet-bonded sp carbons. The synthesis of this sp carbon phase is demonstrated, and other carbon phases are described for possible future synthesis from graphyne without breaking graphyne bonds. While measurements and theory indicate that the reacting graphyne becomes nonplanar because of sheet wrinkling produced by dimensional mismatch between reacted and nonreacted sheet regions, sheet planarity is regained when the reaction is complete.

Improving Bond Dissociations of Reactive Machine Learning Potentials through Physics-Constrained Data Augmentation.

In the field of computational chemistry, predicting bond dissociation energies (BDEs) presents well-known challenges, particularly due to the multireference character of reactive systems. Many chemical reactions involve configurations where single-reference methods fall short, as the electronic structure can significantly change during bond breaking. As generating training data for partially broken bonds is a challenging task, even state-of-the-art reactive machine learning interatomic potentials (MLIPs) often fail to predict reliable BDEs and smooth dissociation curves.

Fentanyl and Fentanyl Analog Screening Using ASAP-MS With LiveID Confirmation.

Rationale: Fentanyl and fentanyl analogs continue to pose a serious threat to the public health. The vast number of fentanyl analogs emerging on the black-market call for optimized analytical methods for the detection, analysis, and characterization of these extremely dangerous drugs.

Methods: Atmospheric pressure solids analysis probe (ASAP) mass spectrometry was used for the rapid analysis of 250 synthetic opioid standards, including 211 fentanyl analogs, 32 non-fentanyl related opioids, and 8 fentanyl precursors.

Facet-controlled electrosynthesis of nanoparticles by combinatorial screening in scanning electrochemical cell microscopy.

Controlled synthesis of faceted nanoparticles on surfaces without explicit use of ligands has gained attention due to their promising applications in electrocatalysis and chemical sensing. Electrodeposition is a desirable method; however, precise control over their size, spatial distribution, and morphology requires extensive optimization. Here, we report the spatially resolved synthesis of shape-controlled Pt nanoparticles and fast screening of synthesis conditions in scanning electrochemical cell microscopy (SECCM) with pulse potentials.

P-P Coupling and Terminal Metal-Phosphorus Intermediates.

Terminal metal-phosphorus (M-P) complexes are of significant contemporary interest as potential platforms for P-atom transfer (PAT) chemistry. Decarbonylation of metal-phosphaethynolate (M-PCO) complexes has emerged as a general synthetic approach to terminal M-P complexes. M-P complexes that are stabilized by strong M-P multiple bonds are kinetically persistent and isolable.

Vitamin B2 Operates by Dual Thermodynamic and Kinetic Mechanisms to Selectively Tailor Urate Crystallization.

Here we demonstrate how a biologically relevant molecule, riboflavin (vitamin B2), operates by a dual mode of action to effectively control crystallization of ammonium urate (NHHU), which is associated with cetacean kidney stones. In situ microfluidics and atomic force microscopy experiments confirm a strong interaction between riboflavin and NHHU crystal surfaces that substantially inhibits layer nucleation and spreading by kinetic mechanisms of step pinning and kink blocking. Riboflavin does not alter the distribution of tautomeric urate isomers, but its adsorption on NHHU crystal surfaces does interfere with the effects of minor urate tautomer by limiting its ability to induce NHHU crystal defects while also suppressing NHHU nucleation and inhibiting crystal growth by 80% at an uncharacteristically low modifier concentration.

Dual-Ligand Assisted Anisotropic Assembly for the Construction of NIR-II Light-Propelled Mesoporous Nanomotors.

The advent of autonomous nanomotors presents exciting opportunities for nanodrug delivery. However, significant potential remains for enhancing the asymmetry of nanomotors and advancing the development of second near-infrared (NIR-II) light-propelled nanomotors capable of operating within deep tissues. Herein, we developed a dual-ligand assisted anisotropic assembly strategy that enables precise regulation of the interfacial energy between selenium (Se) nanoparticle and periodic mesoporous organosilica (PMO).

Enantioselective Total Syntheses of Vallesamidine and Schizozygane Alkaloids.

A general streamlined strategy for the enantioselective total syntheses of the schizozygane family of natural products and related alkaloid vallesamidine is described. Specifically, a catalytic enantioconvergent cross-coupling sets the quaternary stereogenic center in a pluripotent intermediate adorned with an olefin and three orthogonal carboxylate groups, upon which the modularity of the synthesis relies. A late-stage catalytic oxidative lactamization of an alkyne is instrumental in the first-generation synthesis of the schizozygane alkaloids.

Insights into Chemical and Structural Order at Planar Defects in PbMgWO Using Multislice Electron Ptychography.

Switchable order parameters in ferroic materials are essential for functional electronic devices, yet disruptions of the ordering can take the form of planar boundaries or defects that exhibit distinct properties from the bulk, such as electrical (polar) or magnetic (spin) response. Characterizing the structure of these boundaries is challenging due to their confined size and three-dimensional (3D) nature. Here, a chemical antiphase boundary in the highly ordered double perovskite PbMgWO is investigated using multislice electron ptychography.

Lipidome disruption in Alzheimer's disease brain: detection, pathological mechanisms, and therapeutic implications.

Alzheimer's disease (AD) is among the most devastating neurodegenerative disorders with limited treatment options. Emerging evidence points to the involvement of lipid dysregulation in the development of AD. Nevertheless, the precise lipidomic landscape and the mechanistic roles of lipids in disease pathology remain poorly understood.

Understanding the effects of adduct functionalization on C nanocages for the hydrogen evolution reaction.

In this work, we use experimental and theoretical techniques to study the origin of the boosted hydrogen evolution reaction (HER) catalytic activity of two pyridyl-pyrrolidine functionalized C fullerenes. Notably, the mono-(pyridyl-pyrrolidine) penta-adduct of C has exhibited a remarkable HER catalytic activity as a metal-free catalyst, delivering an overpotential () of 75 mV RHE and a very low onset potential of -45 mV RHE. This work addresses fundamental questions about how functionalization on C changes the electron density on fullerene cages for high-performance HER electrocatalysis.

Phytochemical-Based Drug Discovery for Breast Cancer: Combining Virtual Screening and Molecular Dynamics to Identify Novel Therapeutics.

Maternal Embryonic Leucine Zipper Kinase (MELK), a pivotal signaling protein, plays a crucial role in various physiological processes such as cell growth, survival, and differentiation. There is currently a growing interest in MELK as a promising therapeutic target for multiple cancers, including triple-negative breast cancer (TNBC). Exploring MELK as a target offers a prospective strategy to impede cancer progression and enhance the efficacy of conventional anticancer therapies.

Insights into the flexibility of the domain-linking loop in actinobacterial coproheme decarboxylase through structures and molecular dynamics simulations.

Prokaryotic heme biosynthesis in Gram-positive bacteria follows the coproporphyrin-dependent heme biosynthesis pathway. The last step in this pathway is catalyzed by the enzyme coproheme decarboxylase, which oxidatively transforms two propionate groups into vinyl groups yielding heme b. The catalytic reaction cycle of coproheme decarboxylases exhibits four different states: the apo-form, the substrate (coproheme)-bound form, a transient three-propionate intermediate form (monovinyl, monopropionate deuteroheme; MMD), and the product (heme b)-bound form.

A novel method for expressing and purifying large quantities of functional and stable human voltage-gated proton channel (hH1).

Purifying membrane proteins has been the limiting step for studying their structure and function. The challenges of the process include the low expression levels in heterologous systems and the requirement for their biochemical stabilization in solution. The human voltage-gated proton channel (hH1) is a good example of that: the published protocols to express and purify hH1 produce low protein quantities at high costs, which is an issue for systematically characterizing its structure and function.

CaML: Chemistry-informed machine learning explains mutual changes between protein conformations and calcium ions in calcium-binding proteins using structural and topological features.

Proteins' flexibility is a feature in communicating changes in cell signaling instigated by binding with secondary messengers, such as calcium ions, associated with the coordination of muscle contraction, neurotransmitter release, and gene expression. When binding with the disordered parts of a protein, calcium ions must balance their charge states with the shape of calcium-binding proteins and their versatile pool of partners depending on the circumstances they transmit. Accurately determining the ionic charges of those ions is essential for understanding their role in such processes.

Cryo-EM SPR structures of Salmonella typhimurium ArnC; the key enzyme in lipid-A modification conferring polymyxin resistance.

Polymyxins are last-resort antimicrobial peptides administered clinically against multi-drug resistant bacteria, specifically in the case of Gram-negative species. However, an increasing number of these pathogens employ a defense strategy that involves a relay of enzymes encoded by the pmrE (ugd) loci and the arnBCDTEF operon. The pathway modifies the lipid-A component of the outer membrane (OM) lipopolysaccharide (LPS) by adding a 4-amino-4-deoxy-l-arabinose (L-Ara4N) headgroup, which renders polymyxins ineffective.

Global metabolomic alterations associated with endocrine-disrupting chemicals among pregnant individuals and newborns.

Background: Gestational exposure to non-persistent endocrine-disrupting chemicals (EDCs) may be associated with adverse pregnancy outcomes. While many EDCs affect the endocrine system, their effects on endocrine-related metabolic pathways remain unclear. This study aims to explore the global metabolome changes associated with EDC biomarkers at delivery.

Multidimensional library for the improved identification of per- and polyfluoroalkyl substances (PFAS).

As the occurrence of human diseases and conditions increase, questions continue to arise about their linkages to chemical exposure, especially for per-and polyfluoroalkyl substances (PFAS). Currently, many chemicals of concern have limited experimental information available for their use in analytical assessments. Here, we aim to increase this knowledge by providing the scientific community with multidimensional characteristics for 175 PFAS and their resulting 281 ion types.

Urine proteomics defines an immune checkpoint-associated nephritis signature.

Immune checkpoint inhibitor (ICI) therapy is a cornerstone treatment for many cancers, but it can induce severe immunotoxicity, including acute interstitial nephritis (AIN). Currently, kidney biopsy is required to differentiate ICI-AIN from other causes of acute kidney injury (AKI). However, this invasive approach can lead to morbidity, delayed glucocorticoid treatment for patients with AIN, and unnecessarily prolonged suspension of ICI therapy in non-AIN patients.

Binding a C-appended rhenium-(Bispyridine) carbonyl complex to β-Lactoglobulin: Effects of pH & cysteine modification on calyx affinity.

Due to its commercial availability and well-defined structure, the interaction between bovine protein β-lactoglobulin (βLG) and a wide variety of non-native ligands - including transition metal complexes - has been explored, but its application as an artificial metalloenzyme scaffold is limited. This protein is hypothesized to transport fatty acids and other nutrients during juvenile development, and it binds hydrophobic ligands inside a binding pocket constructed upon an 8-stranded β-barrel, called the 'calyx'. Herein, we compare the binding behavior of two rhenium(anthracene-bispyridine) ('Anth-py') tricarbonyl complexes, one with a 12‑carbon chain appended to the ligand scaffold ('Anth-py') to βLG.

Coarse-Graining Chemical Networks by Trimming to Preserve Energy Dissipation.

Continuous production of entropy and the corresponding energy dissipation is a defining characteristic of nonequilibrium systems. When a system's full chemical kinetic description is known, its entropy production rate can be computed from the microscopic rate constants. However, such a calculation typically underestimates energy dissipation when the states of the underlying system are mesoscopic, i.

EPR Characterization of the BlsE Substrate Radical Offers Insight into the Determinants of Reaction Outcome that Distinguish Radical SAM Dioldehydratases from Dehydrogenases.

A small but growing set of radical SAM (-adenosyl-l-methionine) enzymes catalyze the radical mediated dehydration or dehydrogenation of 1,2-diol substrates. In some cases, these activities can be interchanged via minor structural perturbations to the reacting components raising questions regarding the relative importance of hyperconjugation, proton circulation and leaving group stability in determining the reaction outcome. The present work describes trapping and electron paramagnetic resonance (EPR) characterization of an α-hydroxyalkyl radical intermediate during dehydration and dehydrogenation of cytosylglucuronic acid and its derivatives catalyzed by the radical SAM enzyme BlsE and its Glu189Ala mutant from the blasticidin S biosynthetic pathway.

Dietary Interventions, Supplements, and Plant-Derived Compounds for Adjunct Vitiligo Management: A Review of the Literature.

Vitiligo is a chronic autoimmune pigmentation disorder shaped by a complex interplay of genetic predispositions and environmental triggers. While conventional therapies-phototherapy, corticosteroids, and immunosuppressants-can be effective, their benefits are often partial and temporary, with recurrence common once treatment stops. As such, there is increasing interest in exploring complementary approaches that may offer a more sustainable impact.

Targeting Cytokine-Mediated Inflammation in Brain Disorders: Developing New Treatment Strategies.

Cytokine-mediated inflammation is increasingly recognized for playing a vital role in the pathophysiology of a wide range of brain disorders, including neurodegenerative, psychiatric, and neurodevelopmental problems. Pro-inflammatory cytokines such as interleukin-1 (IL-1), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) cause neuroinflammation, alter brain function, and accelerate disease development. Despite progress in understanding these pathways, effective medicines targeting brain inflammation are still limited.