A multifunctional mitochondria-protective gene delivery platform promote intervertebral disc regeneration.

Intervertebral disc degeneration (IDD) is a deleterious condition driven by localized inflammation and the associated disruption of the normal homeostatic balance between anabolism and catabolism, contributing to progressive functional abnormalities within the nucleus pulposus (NP). Despite our prior evidence demonstrating that a miR-21 inhibitor can have regenerative effects that counteract the progression of IDD, its application for IDD treatment remains limited by the inadequacy of current local delivery systems. Here, an injectable tannic acid (TA)-loaded hydrogel gene delivery system was developed and used for the encapsulation of a multifunctional mitochondria-protecting gene nanocarrier (PHs).

Biocompatible Hydrogel Coating on Silicone Rubber with Improved Antifouling and Durable Lubricious Properties.

Silicone rubber is widely used in various medical applications. However, silicone rubber is prone to biofouling due to their affinity for lipids and has a high friction coefficient, which can significantly impact their efficacy and performance used as medical devices. Thus, the development of hydrogels with antifouling and lubricious abilities for the modification of silicone rubber is in high demand.

Development of an injectable oxidized dextran/gelatin hydrogel capable of promoting the healing of alkali burn-associated corneal wounds.

The cornea serves as an essential shield that protects the underlying eye from external conditions, yet it remains highly vulnerable to injuries that could lead to blindness and scarring if not promptly and effectively treated. Excessive inflammatory response constitute the primary cause of pathological corneal injury. This study aimed to develop effective approaches for enabling the functional repair of corneal injuries by combining nanoparticles loaded with anti-inflammatory agents and an injectable oxidized dextran/gelatin/borax hydrogel.

Dual single atomic Ni sites constructing Janus hollow graphene for boosting electrochemical sensing of glucose.

Single atom catalysts (SACs) have attracted attention due to their excellent catalysis activity under specific reactions and conditions. However, the low density of SACs greatly limits catalytic performance. The three-dimensional graphene hollow nanospheres (GHSs) with very thin shell structure can be used as excellent carrier materials.

Radical-Smiles Rearrangement by a Vitamin B2-Derived Photocatalyst in Water.

Herein, we report a catalytic radical-Smiles rearrangement system of arene migration from ether to carboxylic acid with riboflavin tetraacetate (RFT), a readily available ester of natural vitamin B2, as the photocatalyst and water as a green solvent, being free of external oxidant, base, metal, inert gas protection, and lengthy reaction time. Not only the known substituted 2-phenyloxybenzoic acids substrates but also a group of naphthalene- and heterocycle-based analogues was converted to the corresponding aryl salicylates for the first time. Mechanistic studies, especially a couple of kinetic isotope effect (KIE) experiments, suggested a sequential electron transfer-proton transfer processes enabled by the bifunctional flavin photocatalyst.

Alkyne Oxidation by a Vitamin B2-Based Photocatalytic System with Both HO and O as the Oxygen Source.

The employment of readily available photocatalysts and green oxygen atom sources is recognized as a promising strategy to develop sustainable catalysis for oxidation reactions. We herein reported a sacrificial reagent-free system consisting of riboflavin tetraacetate (RFT), an ester of natural vitamin B2 as the photocatalyst, and Sc(OTf) and NaCl as the cocatalysts for alkyne oxidation under blue light or even sunlight irradiation to produce 1,2-diketone in which the oxygen atoms were from both water and molecular oxygen, respectively. A major Cl/Cl• cycle was proposed to be involved and achieved by the excited [RFT-2Sc]* complex via single electron transfer for the first time, distinguished from the OCl active species by a two-electron process in previous flavin-halide photo-oxidation systems.

Photo-Controlled Nano-Supramolecular Size and Reversible Luminescent Behaviors Based on Cucurbit[7]uril Cascaded Assembly.

Supramolecular luminescent material with switchable behavior and photo-induced aggregation with emission enhancement is a current research hot spot. Herein, a size-tunable nano-supramolecular assembly with reversible photoluminescent behavior was constructed by noncovalent polymerization of diarylethene-bridged bis(coumarin) derivative (DAE-CO), cucurbit[7]uril (CB[7]), and β-cyclodextrin-grafted hyaluronic acid (HACD). Benefiting from the macrocyclic confinement effect, the guest molecule DAE-CO was included into the cavity of CB[7] to give enhanced fluorescence emission of the resulting DAE-CO⊂CB[7] with longer lifetime at 432 nm to 1.

Drug-Embedded Nanovesicles Assembled from Peptide-Decorated Hyaluronic Acid for Rheumatoid Arthritis Synergistic Therapy.

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that causes endless pain and poor quality of life in patients. Usage of a lubricant combined with anti-inflammatory therapy is considered a reasonable and effective approach for the treatment of RA. Herein, inspired by glycopeptides, a peptide-decorated hyaluronic acid was synthesized, and the grafted Fmoc-phenylalanine-phenylalanine-COOH (FmocFF) peptide self-assembled with β-sheet conformations could induce the folding of polymer molecular chains to form a vesicle structure in aqueous solution.

Surface Engineering of Central Venous Catheters via Combination of Antibacterial Endothelium-Mimicking Function and Fibrinolytic Activity for Combating Blood Stream Infection and Thrombosis.

Long-term blood-contacting devices (e.g., central venous catheters, CVCs) still face the highest incidence of blood stream infection and thrombosis in clinical application.

Low-Valent Tungsten-Catalyzed Controllable Oxidative Dehydrogenative Coupling of Anilines.

Herein, we have developed an efficient tungsten-catalyzed homogeneous system for oxidative dehydrogenative coupling of anilines to selectively produce various azoaromatics and azoxyaromatics as well as 2-substituted indolone -oxides by simply regulating the reaction solvent with peroxide as a terminal oxidant under additive-free conditions. These findings provide an experimental framework for exploring tungsten catalysis in organic synthesis and offer an efficient and convenient tactic for the selective oxidation of anilines.

A fully degradable transcatheter ventricular septal defect occluder: Towards rapid occlusion and post-regeneration absorption.

Degradable heart occluders are a promising replacement for currently clinically used non-degradable ones without concerns about the complications caused by the persistent residue of a foreign implant. However, the inherent mechanical properties of degradable occluders are poor and decline with material degradation, leading to a preference for a long degradation period upon designing a degradable heart occluder. This configuration can lower the risk of occluder dislodgement but reduce the benefits of degradable implants over their non-degradable counterparts due to a longer retention of foreign materials in the human body.

Hemocompatibility Multi-in-One Hydrogel Coating with ROS-Triggered Inflammation Suppression and Anti-Infection Properties for Blood-Contacting Device.

In traditional blood-contacting medical devices, infection and thrombosis are easily formed on the surface of the materials. In addition, inflammation is also a clinical complication that cannot be ignored. More importantly, there is a mutually promoting relationship between the inflammatory response and the infection as well as thrombosis.

-Arylimidazoliums as Highly Selective Biomimetic Antimicrobial Agents.

Antibiotic resistance has become one of the greatest health threats in the world. In this study, a charge-dispersed dimerization strategy is described for the antimicrobial peptide (AMP) mimics via a tunable cationic charge to improve the selectivity between prokaryotic microbes and eukaryotic cells. This strategy is demonstrated with a series of charge-dispersed AMP mimics based on -arylimidazolium skeletons.

Hydrophosphorylation of electron-deficient alkenes and alkynes mediated by convergent paired electrolysis.

A straightforward and practical strategy for hydrophosphorylation of electron-deficient alkenes and alkynes to access γ-ketophosphine oxides, enabled by a convergent paired electrolysis (CPE) in the absence of a metal, base, and redox reagent, has been described. Mechanistic studies have revealed that the diarylphosphane oxides play the dual role of a phosphorus radical precursor and hydrogen donor in this transformation.

Formation of Iridium(III) and Rhodium(III) Amine, Imine, and Amido Complexes Based on Pyridine-Amine Ligands: Structural Diversity Arising from Reaction Conditions, Substituent Variation, and Metal Centers.

Herein, we present the different coordination modes of half-sandwich iridium(III) and rhodium(III) complexes based on pyridine-amine ligands. The pyridyl-amine iridium(III) and rhodium(III) complexes, the corresponding oxidation pyridyl-imine products, and 16-electron pyridyl-amido complexes can be obtained through the change in reaction conditions (nitrogen/adventitious oxygen atmosphere, reaction time, and solvents) and structural variations in the metal and ligand. Overall, the reaction of pyridine-amine ligands with [(η-C(CH))MCl] (M = Ir or Rh) in the presence of adventitious oxygen afforded the oxidized pyridyl-imine complexes.

Inhibition of [FeFe]-hydrogenase by formaldehyde: proposed mechanism and reactivity of FeFe alkyl complexes.

The mechanism for inhibition of [FeFe]-hydrogenases by formaldehyde is examined with model complexes. Key findings: (i) CH donated by formaldehyde covalently link Fe and the amine cofactor, blocking the active site and (ii) the resulting Fe-alkyl is a versatile electrophilic alkylating agent. Solutions of Fe[(μ-SCH)NH](CO)(PMe) (1) react with a mixture of HBF and CHO to give three isomers of [Fe[(μ-SCH)NCH](CO)(PMe)] ([2]).

A Uniform and Robust Bioinspired Zwitterion Coating for Use in Blood-Contacting Catheters with Improved Anti-Inflammatory and Antithrombotic Properties.

Inflammation and thrombosis are two major complications of blood-contacting catheters that are used as extracorporeal circuits for hemodialysis and life-support systems. In clinical applications, complications can lead to increased mortality and morbidity rates. In this work, a biomimetic erythrocyte membrane zwitterion coating based on poly(2-methacryloyloxyethyl phosphorylcholine-co-dopamine methacrylate) (pMPCDA) copolymers is uniformly and robustly modified onto a polyvinyl chloride (PVC) catheter via mussel-inspired surface chemistry.

Microneedle-mediated vascular endothelial growth factor delivery promotes angiogenesis and functional recovery after stroke.

Ischemic stroke is still the major cause of disability worldwide. Although vascular endothelial growth factor (VEGF) is able to promote both angiogenesis and functional recovery, its use is limited by needle-induced injury, nonhomogenous VEGF distribution, and limited VEGF retention in the brain after intracranial or intravenous injection. Here, we first present a gelatin methacryloyl (GelMA) microneedle (MN)-based platform for the sustained and controlled local delivery of an adeno-associated virus (AAV) expressing human VEGF (AAV-VEGF) that achieves homogenous distribution and high transfection efficiency in ischemic brains.

Dressing Blood-Contacting Materials by a Stable Hydrogel Coating with Embedded Antimicrobial Peptides for Robust Antibacterial and Antithrombus Properties.

Although dressing blood-contacting devices with robust and synergistic antibacterial and antithrombus properties has been explored for several decades, it still remains a great challenge. In order to endow materials with remarkable antibacterial and antithrombus abilities, a stable and antifouling hydrogel coating was developed via surface-initiated polymerization of sulfobetaine methacrylate and acrylic acid on a polymeric substrate followed by embedding of antimicrobial peptides (AMPs), including WR (sequence: WRWRWR-NH) or Bac2A (sequence: RLARIVVIRVAR-NH) AMPs. The chemical composition of the AMP-embedded hydrogel coating was determined through XPS, zeta potential, and SEM-EDS measurements.

Surprising Condensation Reactions of the Azadithiolate Cofactor.

Azadithiolate, a cofactor found in all [FeFe]-hydrogenases, is shown to undergo acid-catalyzed rearrangement. Fe [(SCH ) NH](CO) self-condenses to give Fe [(SCH ) N] (CO) . The reaction, which is driven by loss of NH , illustrates the exchange of the amine group.

CO substitution by PPh in FeS(CO) proceeds via a novel FeS intermediate.

The reaction of FeS(CO) and PPh affords FeS(CO)(PPh) by an unprecedented mechanism involving the intermediacy of SPPh and FeS(CO)(PPh).

A conformally adapted all-in-one hydrogel coating: towards robust hemocompatibility and bactericidal activity.

Hospital-acquired infections and thrombosis caused by bacteria attached to the device surface, or fibrin crosslinking owing to platelet accumulation/activation, are major healthcare challenges that cause morbidity and mortality. To prevent these, surface coating technologies are considered an efficient tool that can combine hemocompatibility and bactericidal activity. In this study, surface-initiated polymerization was conducted to form an all-in-one hydrogel coating that could adapt to diverse medical devices.

Computational and Experimental Investigations of the Fe(μ-S)/Fe(μ-S) Equilibrium.

Density functional theory (DFT) calculations on FeS(CO)(PMe) for = 0, 1, and 2 reveal that the most electron-rich derivatives ( = 2) exist as diferrous disulfides lacking an S-S bond. The thermal interconversion of the Fe(S) and Fe(S) valence isomers is symmetry-forbidden. Related electron-rich diiron complexes [FeS(CN)(CO)] of an uncertain structure are implicated in the biosynthesis of [FeFe]-hydrogenases.