CuBr-Promoted Formal Hydroacylation of 1‑Alkynes with Glyoxal Derivatives: An Unexpected Synthesis of 1,2-Dicarbonyl-3-enes

An efficient and concise protocol has been developed for the highly regio- and stereoselective synthesis of <i>E</i>-1,2-dicarbonyl-3-ene derivatives by a copper-promoted reaction of 1-alkynes with α-carbonyl aldehydes in the presence of morpholine. The products obtained are believed as the formal hydroacylation of the triple bond

Fabrication of dopamine modified polylactide-poly(ethylene glycol) scaffolds with adjustable properties

<p>Bio-based polymers have been widely used to be as scaffolds for repairing the bone defects. However, the polymer scaffolds are generally lack of bioactivity and cell recognition site. Seeking effective ways to improve the bioactivity and interaction between materials and tissue or cells is clinically important for long-term performance of bone repair materials. In this work, polylactide-<i>b</i>-poly(ethylene glycol)-<i>b</i>-polylactide (PLA-PEG-PLA, PLEL) tri-block copolymers were firstly synthesized by ring-opening polymerization of lactide using PEG with various molecular weights. Inspired by excellent adhesion of dopamine (DA), a facile and effective method was developed to fabricate polydopamine (PDA) and polydopamine/nano-hydroxyapatite (PDA/n-HA) modified PLEL scaffolds by deposition of PDA and PDA/n-HA coating. The surface structure, degradation rates and mineralization of the modified PLEL scaffolds were investigated, and obviously improved after immobilization of PDA and PDA/n-HA coatings. Moreover, the biocompatible results showed a significant increase in cells viability and adhesion. Therefore, the surface modification with PDA and PDA/n-HA could not only adjust the properties of scaffolds, but also reinforce the interfacial adhesion between the PLEL and cells.</p

PAMAM Dendrimers with an Oxyethylene Unit-Enriched Surface as Biocompatible Temperature-Sensitive Dendrimers

A novel type of temperature-sensitive dendrimer was synthesized using one-step terminal modification of polyamidoamine dendrimers (PAMAM) with various alkoxy diethylene glycols such as methoxy diethylene glycol, ethoxy diethylene glycol, and propoxy diethylene glycol. The obtained dendrimers exhibited tunable lower critical solution temperature (LCST), depending on PAMAM generation and terminal alkoxy groups. These dendrimers were shown to be taken up by HeLa cells through endocytosis and were trapped in intracellular compartments such as endosomes and lysosomes. Cellular uptake of the dendrimers was enhanced by increasing their incubation temperature above the LCST. In addition, the in vitro cytotoxicity of temperature-sensitive dendrimers at incubation temperatures below and above LCST was much lower than that of their parent PAMAM dendrimers. Results indicate that the dendrimers with oxyethylene unit-enriched surface might be promising to construct intelligent drug delivery systems

Porphyrin Derivative Conjugated with Gold Nanoparticles for Dual-Modality Photodynamic and Photothermal Therapies In Vitro

Gold nanoparticles (Au NPs) have been confirmed to show excellent photothermal conversion property for tumor theranostic applications. To improve the antitumor efficacy, a novel nanoplatform system composed of porphyrin derivative and Au NPs was fabricated to study the dual-modality photodynamic and photothermal therapy with laser irradiation. Modified chitosan was coated on the Au NPs surface via ligand exchange between thiol groups and Au. The chitosan-coated Au NPs (QCS-SH/Au NPs) were further conjugated with meso-tetrakis­(4-sulphonatophenyl)­porphyrin (TPPS) via electrostatic interaction to obtain the porphyrin-conjugated Au hybrid nanoparticles (TPPS/QCS-SH/Au NPs). Size, morphology, and properties of the prepared nanoparticles were confirmed by Zeta potential, nanoparticle size analyzer, transmission electron microscopy (TEM), and UV–vis spectroscopy. Moreover, both photothermal therapy (PTT) and photodynamic therapy (PDT) were investigated. Compared with alone Au NPs or TPPS, the hybrid TPPS/QCS-SH/Au NPs with lower cytotoxicity showed durable elevated temperature to around 56 °C and large amount of singlet oxygen (¹O₂) produced from TPPS. Thus, the hybrid nanoparticles showed a more significant synergistic therapy effect of hyperthermia from PTT as well as ¹O₂ from PDT, which has potential applications in the tumor therapy fields

Fabrication of Biobased Polyelectrolyte Capsules and Their Application for Glucose-Triggered Insulin Delivery

To enhance the glucose sensitivity and self-regulated release of insulin, biobased capsules with glucose-responsive and competitive properties were fabricated based on poly­(γ-glutamic acid) (γ-PGA) and chitosan oligosaccharide (CS) polyelectrolytes. First, poly­(γ-glutamic acid)-<i>g</i>-3-aminophenylboronic acid) (γ-PGA-<i>g</i>-APBA) and galactosylated chitosan oligosaccharide (GC) were synthesized by grafting APBA and lactobionic acid (LA) to γ-PGA and CS, respectively. The (γ-PGA<i>-<i>g</i>-</i>APBA/GC)₅ capsules were then prepared by layer-by-layer (LBL) assembly of γ-PGA-<i>g</i>-APBA and GC via electrostatic interaction. The size and morphology of the particles and capsules were investigated by DLS, SEM, and TEM. The size of the (γ-PGA<i>-<i>g</i>-</i>APBA/GC)₅ capsules increased with increasing glucose concentration due to the swelling of the capsules. The capsules could be dissociated at high glucose concentration due to the breaking of the cross-linking bonds between APBA and LA by the competitive reaction of APBA with glucose. The encapsulated insulin was able to undergo self-regulated release from the capsules depending on the glucose level and APBA composition. The amount of insulin release increased with incubation in higher glucose concentration and decreased with higher APBA composition. Moreover, the on–off regulation of insulin release from the (γ-PGA-<i>g</i>-APBA/GC)₅ capsules could be triggered with a synchronizing and variation of the external glucose concentration, whereas the capsules without the LA functional groups did not show the on–off regulated release. Furthermore, the (γ-PGA-<i>g</i>-APBA/GC)₅ capsules are biocompatible. These (γ-PGA-<i>g</i>-APBA/GC)₅ with good stability, glucose response, and controlled insulin delivery are expected to be used for future applications to glucose-triggered insulin delivery

A high-speed microscopy system based ondeep learning to detect yeast-like fungi cellsin blood: supplementary materials

Background: Blood-invasive fungal infections can cause the death of patients, while diagnosis of fungalinfections is challenging. Methods: A high-speed microscopy detection system was constructed thatincluded a microfluidic system, a microscope connected to a high-speed camera and a deep learninganalysis section. Results: For training data, the sensitivity and specificity of the convolutional neuralnetwork model were 93.5% (92.7–94.2%) and 99.5% (99.1–99.5%), respectively. For validating data, thesensitivity and specificity were 81.3% (80.0–82.5%) and 99.4% (99.2–99.6%), respectively. Cryptococcalcells were found in 22.07% of blood samples. Conclusion: This high-speed microscopy system can analyzefungal pathogens in blood samples rapidly with high sensitivity and specificity and can help dramaticallyaccelerate the diagnosis of fungal infectious diseases.</p

Facile Synthesis of Hyperbranched Polymers by Sequential Polycondensation

Hyperbranched polymers are an important class of soft nanomaterial, but the synthesis of hyperbranched polymers with well-defined dendritic structure from readily available monomers remains a challenge in polymer chemistry. We herein report a sequential polycondensation method for the one-pot synthesis of hyperbranched polymers with tunable structure and high degree of branching from commercial available monomers. Specifically, in the polycondensation process of equimolar difunctional haloalkane (A₂-type monomers) and trifunctional dihydroxybenzoic acid (CB₂-type monomers) using K₂CO₃ as the base, the aliphatic nucleophilic substitution reactivity sequence of the functional groups derived from CB₂ monomers is C > second B > first B ≫ original B, thereby producing hyperbranched poly­(ester ether)­s with high degree of branching (DB > 0.6). Moreover, the surface functionality of the hyperbranched poly­(ester ether)­s could be facilely tailored by just introducing A-type monofunctional reagents into the one-pot A₂ + CB₂ polymerization system

High-Performance PEBA2533-Functional MMT Mixed Matrix Membrane Containing High-Speed Facilitated Transport Channels for CO₂/N₂ Separation

A novel mixed matrix membrane was fabricated by establishing montmorillonite (MMT) functionalized with poly­(ethylene glycol) methyl ether (PEG) and aminosilane coupling agents in a PEBA membrane. The functional MMT played multiple roles in enhancing membrane performance. First, the MMT channels could be used as high-speed facilitated transport channels, in which the movable metal cations acted as carriers of CO₂ to increase the CO₂ permeability. Second, due to mobility of long-chain aminos and reversible reactions between CO₂ and amine groups, the functional MMT could actively catch the CO₂, not passively wait for arrival of CO₂, which can facilitate the CO₂ transport. At last, PEG consisting of EO groups had excellent affinity for CO₂ to enhance the CO₂/N₂ selectivity. Thus, the as-prepared functional MMMs exhibited good CO₂ permeability and CO₂/N₂ selectivity. The functional MMM doped with 40 wt % of MMT-HD702-PEG5000 displayed optimal gas separation with a CO₂ permeability of 448.45 Barrer and a CO₂/N₂ selectivity of 70.73, surpassing the upper bound lines of the Robeson study of 2008

Engineering a Heterophase Interface by Tailoring the Pt Coverage Density on an Amorphous Ru Surface for Ultrasensitive H₂S Detection

Amorphous/crystalline heterophase engineering is emerging as an attractive strategy to adjust the properties and functions of nanomaterials. Here, we reveal a heterophase interface role by precisely tailoring the crystalline Pt coverage density on an amorphous Ru surface (cPt/aRu) for ultrasensitive H2S detection. We found that when the atomic ratio of Pt/Ru increased from 10 to 50%, the loading modes of Pt changed from island coverage (1cPt/aRu) to cross-linkable coverage (3cPt/aRu) and further to dense coverage (5cPt/aRu). The differences in coverage models further regulate the chemical adsorption of H2S on Pt and the electronic transformation process on Ru, which can be proved by ex situ X-ray photoelectron spectroscopy experiments. Notably, a special cross-linkable coverage 3cPt/aRu on ZnO shows the best gas-sensitive performance, in which the operating temperature reduces from 240 to 160 °C compared with pristine ZnO and the selectivity coefficient for H2S gas improves from ∼1.2 to ∼4.6. This is mainly benefit from the maximized exposure of the amorphous/crystalline heterophase interface. Our work thus provides a new platform for future applications of amorphous/crystalline heterogeneous nanostructures in gas sensors and catalysis

NbSe₂ Nanosheet Supported PbBiO₂Br as a High Performance Photocatalyst for the Visible Light-driven Asymmetric Alkylation of Aldehyde

Visible light photoredox catalysis has been demonstrated to be a promising and green strategy for organic synthesis. In this study, a nanocomposite of PbBiO₂Br nanoparticles and NbSe₂ nanosheet was prepared as a high performance photocatalyst for the visible light-driven asymmetric alkylation of aldehyde. It was found that the introduction of a small amount of NbSe₂ (0.5 wt %) to the PbBiO₂Br semiconductor could result in ∼50% increase in the yield of the final product. This study shows that NbSe₂ nanosheets can be used as an efficient support to suppress the recombination of photoinduced electron–hole pairs and contribute to the enhanced photocatalytic performances of semiconductors in the visible light-driven catalysis