Lubricant skin on diverse biomaterials with complex shapes via polydopamine-mediated surface functionalization for biomedical applications.

Implantable biomedical devices require an anti-biofouling, mechanically robust, low friction surface for a prolonged lifespan and improved performance. However, there exist no methods that could provide uniform and effective coatings for medical devices with complex shapes and materials to prevent immune-related side effects and thrombosis when they encounter biological tissues. Here, we report a lubricant skin (L-skin), a coating method based on the application of thin layers of bio-adhesive and lubricant-swellable perfluoropolymer that impart anti-biofouling, frictionless, robust, and heat-mediated self-healing properties. We demonstrate biocompatible, mechanically robust, and sterilization-safe L-skin in applications of bioprinting, microfluidics, catheter, and long and narrow medical tubing. We envision that diverse applications of L-skin improve device longevity, as well as anti-biofouling attributes in biomedical devices with complex shapes and material compositions.

Heterogeneous electrochemical immunoassay of hippuric acid on the electrodeposited organic films.

By directly coordinating hippuric acid (HA) to the ferrate (Fe) as an electron transfer mediator, we synthesized a Fe-HA complex, which shows a good electrochemical signal and thus enables the electrochemical immunoanalysis for HA. We electrodeposited organic films containing imidazole groups on the electrode surface and then bonded Ni ion (positive charge) to induce immobilization of Fe-HA (negative charge) through the electrostatic interaction. The heterogeneous competitive immunoassay system relies on the interaction between immobilized Fe-HA antigen conjugate and free HA antigen to its antibody (anti-HA). The electric signal becomes weaker due to the hindered electron transfer reaction when a large-sized HA antibody is bound onto the Fe-HA. However, in the presence of HA, the electric signal increases because free HA competitively reacts with the HA antibody prior to actual reaction and thus prevents the HA antibody from interacting with Fe-HA at the electrode surface. This competition reaction enabled an electrochemical quantitative analysis of HA concentration with a detection limit of 0.5 µg mL(-1), and thus allowed us to develop a simple and rapid electrochemical immunosensor.

5-Substituted-2-furaldehydes: a synthetic protocol utilizing an organozinc route.

Facile synthetic routes for the preparation of a wide range of 5-substituted 2-furaldehydes have been revealed. They were accomplished through either Pd-catalyzed cross-coupling reaction of various aryl- and heteroarylzinc halides with 5-bromo-2-furaldehyde or utilization of a new organozinc reagent, 5-(1,3-dioxolan-2-yl)-2-furanylzinc bromide, which was easily prepared by the direct insertion of highly active zinc to 2-(5-bromofuran-2-yl-1,3-dioxolane. Of special note is the uniqueness of using a new organozinc reagent, representing a first example of the direct synthesis of the corresponding organozinc halide. The subsequent coupling reactions in various types of reaction conditions led to the formation of somewhat different furan derivatives. It is also of significance that all of the cross-coupling reactions were carried out under mild conditions.

Recent advance in heterocyclic organozinc and organomanganese compounds; direct synthetic routes and application in organic synthesis.

A practical synthetic route for the preparation of 2-pyridyl and 3-pyridyl derivatives has been accomplished by utilizing a simple coupling reaction of stable 2-pyridylzinc bromides and 3-pyridylzinc bromides. The organozincs used in this study were easily prepared via the direct insertion of active zinc into the corresponding bromopyridines. The subsequent coupling reactions with a variety of different electrophiles have afforded the corresponding coupling products. Using highly active manganese, a variety of Grignard-type organomanganese reagents have been obtained. The subsequent coupling reactions of the resulting organomanganese reagents with several electrophiles have also been accomplished under mild conditions.