Shuangling Zhong

Effect of fiber alignment in electrospun scaffolds on keratocytes and corneal epithelial cells behavior

The contribution of fiber alignment of scaffold on cellular mechanisms was evaluated by a comparative study of two different cells sourced from cornea. Electrospun scaffolds with similar composition and comparable fiber size were fabricated into randomly oriented and aligned scaffolds, which bear paralleled degradation of gelatin. Tensile test of wet scaffolds indicated that fiber alignment could influence its mechanical properties. Due to the unidirectional fiber orientation, aligned scaffold exhibited higher tensile modulus, higher break strength, and lower elongation at break than randomly oriented scaffold. The effect of fiber alignment on cells behavior was evaluated by cell morphology, specific protein expression, adhesion, and proliferation. Different corneal cells responded uniquely to fiber alignment of scaffold, keratocytes interacting more favorably on alignment scaffold and corneal epithelial cells more favorably on randomly oriented scaffold. These results confirmed that fiber alignment of scaffold would be benefit for cell proliferation if its contact guidance coincided with the cell shape and cytoskeletal tension. This finding is important to envisage an advanced composite scaffold that incorporates randomly oriented and aligned fibers for the growth and control of different cell types required for the successful development of corneal grafts by tissue engineering.

A Facile Sonochemical Route for the Fabrication of Magnetic Protein Microcapsules for Targeted Delivery

Protein microcapsules have received considerable attention as effective drug delivery carriers for the treatment of deadly diseases, such as cancer, in the biomedical field. Up to now, extensive efforts have been devoted to fabricate the protein microcapsules and several approaches have been developed. Suslick and co-workers used high-intensity ultrasound to make aqueous suspensions of proteinaceous microcapsules filled with water-insoluble liquids and demonstrated the chemical mechanism of their formation. Lu et al. fabricated protein capsules through protein adsorption at the surface of the organic droplets followed by evaporation of the organic solvent. Balabushevich et al. produced stable polyelectrolyte capsules by the layer-by-layer (LbL) assembling of biodegradable polyelectrolytes, dextran sulfate, and protamine on melamine formaldehyde (MF) microcores followed by core decomposition at low pH. Among the various routes, the sonochemical method has proved to be a simple and effective technique for fabricating protein microcapsules due to the convenient processing and experimental setup, significant saving in time, and excellent products. In addition, the hydrophobic drugs could be directly loaded into protein microcapsules by dissolving drugs in the oil phase before sonication. Magnetic nanoparticles (MNPs), especially iron oxide (Fe3O4) MNPs, also have shown great prospect in biomedical application due to their good biocompatibility, strong superparamagnetism, nontoxicity, and easy preparation proACHTUNGTRENNUNGcess.[20–28] Introducing Fe3O4 MNPs into the biocompatible protein microcapsules are of particular interest, because protein microcapsules functionalized with Fe3O4 MNPs would possess several attractive advantages from a pharmaceutical standpoint:

Preparation of protein microcapsules with narrow size distribution by sonochemical method

Protein microcapsules with narrow size distribution have been prepared by sonochemical method which is a simple, fast, environmental friendly and cost-effective method. The prepared microcapsules are composed of a water-insoluble core and an outer protein shell. The hydrophobic drugs could be encapsulated into protein microcapsules directly via sonochemical method by dissolving drugs in the nontoxic and edible vegetable oil before ultrasonication, which is a potential solution for drug resistance by hiding cytotoxic drugs in the carrier and allows for the delivery of high doses in relatively small volume. The size and size distribution of protein microcapsules are very important for their practical application. In this paper, the factors affecting the size and size distribution of protein microcapsules are investigated in detail. Moreover, confocal laser scanning microscopy and transmission electron microscopy confirmed that the protein microcapsules with narrow size distribution were obtained.

Pd-catalyzed desulfitative and denitrogenative Suzuki-type reaction of arylsulfonyl hydrazides

A palladium-catalyzed desulfitative–denitrogenative coupling of arylsulfonyl hydrazides and arylboronic acids with the assistance of catalytic ligands is described. The reaction showed very good selectivity and tolerated a wide range of functionalities without the aid of expensive copper- or silver-based stoichiometric co-oxidants. We have successfully applied this new cross-coupling reaction to the synthesis of terphenyls and OTBN.

Effects of temperature and concentration on the structure of ethylene oxide–propylene oxide–ethylene oxide triblock copolymer (Pluronic P65) in aqueous solution: a molecular dynamics simulation study

The effects of temperature and solution concentration on the structure of triblock polymeric surfactant (ethylene oxide)19(propylene oxide)29(ethylene oxide)19 (Pluronic P65) have been investigated by fully atomistic molecular dynamics simulations. The Flory–Huggins interaction parameter χ, hydrogen bonding and molecular mobility in the aqueous solution of P65 were investigated covering a composition range of 0.1–0.73 (water weight fraction) and a temperature range of 273–373 K. The Flory–Huggins parameters indicated that propylene oxide (PO) segments became hydrophobic with the increase in temperature, whereas ethylene oxide (EO) segments remained hydrophilic, which caused the increase in repulsion between EO and PO segments. The intermolecular hydrogen bonds in P65 solution including water–water hydrogen bonds and water–P65 hydrogen bonds increased with the increase in solution concentration and decreased with the increase in temperature. The critical micellar temperature of Pluronic P65 predicted by Flory–Huggins interaction parameter χ and hydrogen bonding was in good agreement with experimental data.

Synthesis and surface properties of semi-interpenetrating fluorine-containing polyacrylate and epoxy resin networks

Semi-interpenetrating polymer networks (Semi-IPNs) based on fluorine-containing polyacrylate and epoxy resin were synthesized by the simultaneous polymerization of fluorine-containing acrylate and epoxy resin. Fourier transform infrared (FTIR) spectrometry and X-ray photoelectron spectroscopy (XPS) analyses proved that the fluorine-containing groups have been introduced into Semi-IPNs successfully. In addition, XPS analysis intuitively showed that the fluorine content of the film-air interface of the interpenetrating fluorine-containing polyacrylate and epoxy resin networks (FPAER-SIPNs) film was much higher than that of the film-glass interface. It is noted that the introduction of fluorine-containing groups significantly improved the hydrophobic property of polymer networks. Moreover, when the fluorine content increased, the contact angle of water on FPAER-SIPNs film was increased obviously and the water uptake was decreased gradually. These results indicated that introducing fluorine-containing groups to SIPNs has potential advantage for improving the surface properties of epoxy resin.

Assembly of SnO2 quantum dots on RGO to form SnO2/N doped RGO as a high-capacity anode material for lithium ion batteries

We demonstrate a fast and facile ultrasound-assisted method for the synthesis of ultrasmall SnO2 quantum dots with an average particle size of 3 nm followed by a self-assembly process on reduced graphene oxide nanosheets (RGO) to build a high-capacity anode material for lithium ion batteries (LIB). The bifunctional aminocaproic acid (AHA) plays a key role in our synthesis. It not only protected the ultrasmall SnO2 nanocrystals but also changed the SnO2 surface potential to +41.4 eV. More importantly, AHA was also used as a nitrogen source. It opens a new window to use this simple and low-cost method to fabricate complex graphene-based hybrid nanomaterials.

Multi-functional Au/CdS/Fe3O4/RGO hybrid nanomaterials with enhanced photocatalytic activity

A facile and low-cost layer-by-layer technology has been developed to synthesize a multi-functional Au/CdS/Fe3O4/reduced graphene oxide (RGO) hybrid nanomaterial. The RGO nanosheets are indispensable, as they act not only as a supporter to hold the multiple components together, but also as an electron acceptor and transporter to efficiently hinder the recombination of the photogenerated electron–hole pairs.

Aqueous synthesis of Pt supported 3D flower-like Co3O4 nanostructures with thin nanosheets as building blocks

Uniform and monodisperse Pt supported Co3O4 nanoflowers with thin nanosheets as building blocks are successfully synthesized via a simple hydrothermal strategy followed by a morphology-kept calcining treatment. The growth mechanism has been studied in-depth. The result has shown that such synthesis is highly sensitive to the concentration of urea, and more importantly, PVP and L-lysine which are also indispensable in that they are beneficial to the formation of sheet-like building blocks. In the following catalytic test for the CO oxidation reaction, the as-obtained Pt–Co3O4 nanoflower sample has shown much higher catalytic performance compared with a Pt-commercial Co3O4 sample.