Zein nanospheres assisting inorganic and organic drug combination to overcome stent implantation-induced thrombosis and infection.

The complication of stent implantation is the biggest obstacle to the success of its clinical application. In this study, we developed a combination way of 3D printing and the coating technique for preparation of functional polyurethane stents against stent implantation-induced thrombosis and postoperative infection. SEM, XPS, static water contact angle, and XRD demonstrated that the functional polyurethane stent had a 37 µm-thickness membrane composed of zein nanospheres (250-350 nm). Meanwhile, ZnO nanoparticles were encapsulated in zein nanospheres while heparin was adsorbed on the surface, causing 97.1 ± 6.4 % release of heparin in 120 min (first-order kinetic model) and 62.7 ± 5.6 % release of Zn2+ in 9 days (Korsmeyer-Peppas model). The mechanical analysis revealed that the functional polyurethane stents had about 8.61 MPa and 2.5 MPa tensile strength and bending strength, respectively. The in vitro biological analysis showed that the functional polyurethane stents had good EA.hy926 cells compatibility (97.9 ± 3.8 %), anti-coagulation response (comparable plasma protein, platelet adhesion and suppressed clotting) and sustained antibacterial activities by comparison with the bare polyurethane stent. The preliminary evaluation by rabbit ex vivo carotid artery intervention experiment demonstrated that the functional polyurethane stents could maintain blood circulation under the continuous stresses of blood flow. Meanwhile, the detailed data from the simulated implant infection experiment in vivo showed the functional polyurethane stents could effectively reduce microbial infection by 3-6 times lower and improve fibrosis and macrophage infiltration.

Photoinduced Copper-Catalyzed Site-Selective C(sp2)-C(sp) Cross-Coupling via Aryl Sulfonium Salts.

The classical Sonogashira reaction of aryl electrophiles in the presence of Pd catalysts has been well established as a potent method for arylalkyne synthesis. However, the site-selective C(sp2)-C(sp) cross-coupling strategy using a non-noble-metal catalyst is rare. An efficient alternative approach for the synthesis of arylalkynes via a Cu-catalyzed Sonogashira-type reaction promoted by visible light is described. This method enables site-selective alkynylation from aryl sulfonium salts derived from diverse arenes to a set of arylalkynes with high selectivity and high functional-group compatibility. Moreover, rapid alkynylation of drug molecules is demonstrated.

Sorting Liquid Droplets by Surface Tension Using Devices with Quasi-Superamphiphobic Coatings.

Any solid surface with homogenous or varying surface energy can spontaneously show variable wettability to liquid droplets with different or identical surface tensions. Here, we studied a glass slide sprayed with a quasi-superamphiphobic coating consisting of a hexane suspension of perfluorosilane-coated nanoparticles. Four areas on the glass slide with a total length of 7.5 cm were precisely tuned via ultraviolet (UV) irradiation, and droplets with surface tensions of 72.1-33.9 mN m-1 were categorized at a tilting angle of 3°. Then, we fabricated a U-shaped device sprayed with the same coating and used it to sort the droplets more finely by rolling them in the guide groove of the device to measure their total rolling time and distance. We found a correlation between ethanol content/surface tension and rolling time/distance, so we used the same device to estimate the alcoholic strength of Chinese liquors and to predict the surface tension of ethanol aqueous solutions.

Copper-catalyzed intramolecular cyclization of N-propargyl-adenine: synthesis of purine-fused tricyclics.

A novel protocol to construct fluorescent purine-fused tricyclic products via intramolecular cyclization of N-propargyl-adenine has been developed. With CuBr as the catalyst, a series of purine-fused tricyclic products were obtained in good to excellent yields (19 examples, 75-89% yields). When R2 was a hydrogen atom in N-propargyl-adenines, the reactions only afforded the endocyclic double bond products. When R2 was an aryl group, the electron-donating groups favored the endocyclic double bond products, while the electron-withdrawing groups favored the exocyclic double bond products.