Sulfoxide-Containing Polyacrylamides Prepared by PICAR ATRP for Biohybrid Materials.

Water-soluble and biocompatible polymers are of interest in biomedicine as the search for alternatives to PEG-based materials becomes more important. In this work, the synthesis of a new sulfoxide-containing monomer, 2-(methylsulfinyl)ethyl acrylamide (MSEAM), is reported. Well-defined polymers were prepared by photoinduced initiators for continuous activator regeneration atom transfer radical polymerization (PICAR ATRP).

Diverse Proton-Conducting Nanotubes via a Tandem Macrocyclization and Assembly Strategy.

Macrocycles that assemble into nanotubes exhibit emergent properties stemming from their low dimensionality, structural regularity, and distinct interior environments. We report a versatile strategy to synthesize diverse nanotube structures in a single, efficient reaction by using a conserved building block bearing a pyridine ring. Imine condensation of a 2,4,6-triphenylpyridine-based diamine with various aromatic dialdehydes yields chemically distinct pentagonal [5 + 5], hexagonal [3 + 3], and diamond-shaped [2 + 2] macrocycles depending on the substitution pattern of the aromatic dialdehyde monomer.

Photon Upconversion in a Glowing Metal-Organic Framework.

The interaction of low-energy light with matter that leads to the production of high-energy light is known as photon upconversion. This phenomenon is of importance because of its potential applications in optoelectronics, energy harvesting, and the biomedical arena. Herein, we report a pillared-paddlewheel metal-organic framework (MOF), constructed from a tetrakis(4-carboxyphenyl)porphyrin sensitizer and a dipyridyl thiazolothiazole annihilator, designed for efficient triplet-triplet annihilation upconversion (TTA-UC).

Supramolecular Porous Organic Nanocomposites for Heterogeneous Photocatalysis of a Sulfur Mustard Simulant.

Efficient heterogeneous photosensitizing materials require both large accessible surface areas and excitons of suitable energies and with well-defined spin structures. Confinement of the tetracationic cyclophane (ExBox ) within a nonporous anionic polystyrene sulfonate (PSS) matrix leads to a surface area increase of up to 225 m g in ExBox•PSS. Efficient intersystem crossing is achieved by combining the spin-orbit coupling associated to Br heavy atoms in 1,3,5,8-tetrabromopyrene (TBP), and the photoinduced electron transfer in a TBP⊂ExBox supramolecular dyad.

p-Substituted Tris(2-pyridylmethyl)amines as Ligands for Highly Active ATRP Catalysts: Facile Synthesis and Characterization.

A facile and efficient two-step synthesis of p-substituted tris(2-pyridylmethyl)amine (TPMA) ligands to form Cu complexes with the highest activity to date in atom transfer radical polymerization (ATRP) is presented. In the divergent synthesis, p-Cl substituents in tris(4-chloro-2-pyridylmethyl)amine (TPMA ) were replaced in one step and high yield by electron-donating cyclic amines (pyrrolidine (TPMA ), piperidine (TPMA ), and morpholine (TPMA )) by nucleophilic aromatic substitution. The [Cu (TPMA )Br] complexes exhibited larger energy gaps between frontier molecular orbitals and >0.

XCage: A Tricyclic Octacationic Receptor for Perylene Diimide with Picomolar Affinity in Water.

The rational design of wholly synthetic receptors that bind active substrates with ultrahigh affinities is a challenging goal, especially in water. Here, we report the synthesis of a tricyclic octacationic cyclophane, which exhibits complementary stereoelectronic binding toward a widely used fluorescent dye, perylene diimide, with picomolar affinity in water. The ultrahigh binding affinity is sustained by a large and rigid hydrophobic binding surface, which provides a highly favorable enthalpy and a slightly positive entropy of complexation.

Preparation of Well-Defined Polymers and DNA-Polymer Bioconjugates via Small-Volume eATRP in the Presence of Air.

An aqueous electrochemically mediated atom transfer radical polymerization (eATRP) was performed in a small volume solution (75 μL) deposited on a screen-printed electrode (SPE). The reaction was open to air, thanks to the use of glucose oxidase (GOx) as an oxygen scavenger. Well-defined poly(2-(methylsulfinyl)ethyl acrylate) (PMSEA), poly(oligo(ethylene oxide) methyl ether methacrylate) (POEOMA), and corresponding DNA-polymer biohybrids were synthesized by the small-volume eATRP at room temperature.

Nanoparticle physicochemical properties determine the activation of intracellular complement.

The complement system plays an essential role in both innate and adaptive immunity. The traditional understanding of this system comes from studies investigating complement proteins produced by the liver and present in plasma to "complement" the immune cell-mediated response to invading pathogens. Recently, it has been reported that immune cells including, but not limited to, T-cells and monocytes, express complement proteins.

Enzymatically Degassed Surface-Initiated Atom Transfer Radical Polymerization with Real-Time Monitoring.

Polymer brush coatings are frequently prepared by radical polymerization, a notoriously oxygen sensitive process. Glucose oxidase (GOx) can inexpensively enable radical polymerization in solution by enzymatically consuming oxygen as it oxidizes glucose. Here, we report the growth of polymeric brushes using GOx-assisted atom transfer radical polymerization (ATRP) from a surface while open to air.

Biocatalytic "Oxygen-Fueled" Atom Transfer Radical Polymerization.

Atom transfer radical polymerization (ATRP) can be carried out in a flask completely open to air using a biocatalytic system composed of glucose oxidase (GOx) and horseradish peroxidase (HRP) with an active copper catalyst complex. Nanomolar concentrations of the enzymes and ppm amounts of Cu provided excellent control over the polymerization of oligo(ethylene oxide) methyl ether methacrylate (OEOMA ), generating polymers with high molecular weight (M >70 000) and low dispersities (1.13≤Đ≤1.

Ultrasonication-Induced Aqueous Atom Transfer Radical Polymerization.

A new procedure for ultrasonication-induced atom transfer radical polymerization (sono-ATRP) in aqueous media was developed. Polymerizations of oligo(ethylene oxide) methyl ether methacrylate (OEOMA) and 2-hydroxyethyl acrylate (HEA) in water were successfully carried out in the presence of ppm amounts of CuBr catalyst and tris(2-pyridylmethyl)amine ligand when exposed to ultrasonication (40 kHz, 110 W) at room temperature. Aqueous sono-ATRP enabled polymerization of water-soluble monomers with excellent control over the molecular weight, dispersity, and high retention of chain-end functionality.

Synthesis of Polymer Bioconjugates via Photoinduced Atom Transfer Radical Polymerization under Blue Light Irradiation.

A rapid blue-light-induced atom transfer radical polymerization (ATRP) was conducted in a biologically friendly environment. Well-controlled polymerization of oligo(ethylene oxide) methyl ether methacrylate (OEOMA) was successfully performed in aqueous media (1X PBS) under irradiation by blue LED strips. With 10.

A Breathing Atom-Transfer Radical Polymerization: Fully Oxygen-Tolerant Polymerization Inspired by Aerobic Respiration of Cells.

The first well-controlled aqueous atom-transfer radical polymerization (ATRP) conducted in the open air is reported. This air-tolerant ATRP was enabled by the continuous conversion of oxygen to carbon dioxide catalyzed by glucose oxidase (GOx), in the presence of glucose and sodium pyruvate as sequential sacrificial substrates. Controlled polymerization using initiators for continuous activator regeneration (ICAR) ATRP of oligo(ethylene oxide) methyl ether methacrylate (OEOMA, M =500) yielded polymers with low dispersity (1.

Correction: Facile synthesis of stable, water soluble, dendron-coated gold nanoparticles.

Correction for 'Facile synthesis of stable, water soluble, dendron-coated gold nanoparticles' by Alan E. Enciso, et al., Nanoscale, 2017, 9, 3128-3132.

Facile synthesis of stable, water soluble, dendron-coated gold nanoparticles.

Upon reduction with sodium borohydride, diazonium tetrachloroaurate salts of triazine dendrons yield dendron-coated gold nanoparticles connected by a gold-carbon bond. These robust nanoparticles are stable in water and toluene solutions for longer than one year and present surface groups that can be reacted to change surface chemistry and manipulate solubility. Molecular modeling was used to provide insight on the hydration of the nanoparticles and their observed solubilties.

Thermoregulated Coacervation, Metal-Encapsulation and Nanoparticle Synthesis in Novel Triazine Dendrimers.

The synthesis and solubility behaviors of four generation five (G5) triazine dendrimers are studied. While the underivatized cationic dendrimer is soluble in water, the acetylated and propanoylated derivatives undergo coacervation in water upon increasing temperature. Occurring around room temperature, this behavior is related to a liquid-liquid phase transition with a lower critical solution temperature (LCST) and is explained by differences in composition, notably, the hydrophobic nature of the terminal groups.

Nanoparticle Effects on Human Platelets in Vitro: A Comparison between PAMAM and Triazine Dendrimers.

Triazine and PAMAM dendrimers of similar size and number of cationic surface groups were compared for their ability to promote platelet aggregation. Triazine dendrimers (G3, G5 and G7) varied in molecular weight from 8 kDa-130 kDa and in surface groups 16-256. PAMAM dendrimers selected for comparison included G3 (7 kDa, 32 surface groups) and G6 (58 kDa, 256 surface groups).

Dendrimers terminated with dichlorotriazine groups provide a route to compositional diversity.

Triazine dendrimers terminated with either four or eight dichlorotriazines can be prepared in high yields by reacting an amine-terminated dendrimer with cyanuric chloride. These materials exist as white powders and are stable to storage at room temperature. Sequential nucleophilic aromatic substitution with two different amine nucleophiles yields compounds that display the desired compositional diversity.

Computational design principles for the discovery of bioactive dendrimers: [s]-triazines and other examples.

Introduction: Chemistry yields dendrimers of many classes and compositions. Translating this synthetic success to bioactivity is significantly aided by the use of computational modeling and our knowledge of the three-dimensional shapes of these macromolecules.

Areas Covered: This review discusses the lessons learned during the investigations of [s]-triazine dendrimers.