We reportt he synthesis of thioether with high regioselectivity.T he reaction proceeds through regioselective brominationf ollowed by ac opper/oxalicd iamide-catalyzed CÀSb ond cross-coupling reaction. Functional groups, such as fluoro, chloro, trifluoromethyl, nitro, unprotecteda mine and pyridine, are tolerated by the reaction conditions. Scheme2.Scope of thiols with anisole.Scheme3.Scopeo fa reneswith thiols.Scheme4.Scopeo fp henol and aniline with thiols.Scheme5.Plausible mechanism for para-selectiveC ÀHt hioetherification.

The main issue of transdermal drug delivery is that macromolecular drugs cannot diffuse through the stratum corneum of skin. Many studies have pursued micro-sized needles encapsulated with drugs to overcome this problem, as these needles can pierce the stratum corneum and allow drugs to enter the circulatory system of the human body. However, most microneedle fabrication processes are time-consuming and require expensive equipment. In this study, we demonstrate a rapid method for fabricating a microneedle mold using drawing lithography and a UV-cured resin. The mold was filled with a water-soluble material, polyvinylpyrrolidone (PVP), which was then demolded to produce a water-soluble microneedle array. The results of an in vitro skin insertion test using PVP microneedles and pig ear skin demonstrated the feasibility of the microneedle mold. In addition, by controlling the viscosity of the UV-cured resin through various heat treatments, microneedles with different heights and aspect ratios were produced. Compared with other methods, this technology significantly simplifies and accelerates the mold fabrication process. In addition, the required equipment is relatively simple and inexpensive. Through this technology, we can rapidly fabricate microneedle molds with controllable dimensions for various applications.

In this study, a nanocomposite coating composed of polydopamine, functionalized poly­(3,4-ethylene­dioxythiophene) (PEDOT), and silver nanoparticles (AgNPs) was synthesized through layer-by-layer deposition. Biomimitic polydopamine and hydroxyl-functionalized PEDOT were used to enhance the adhesion strength. The deposition of PEDOT functionalized with zwitterionic phosphorylcholine can contribute to the antifouling property. After immersion in the AgNO3 solution, Ag+ ions were adsorbed on PEDOT films and further reduced to form AgNPs spontaneously, which conferred antibacterial properties on these nanocomposite films. Escherichia coli and Streptococcus mutans were chosen to represent two common Gram-negative and Gram-positive oral pathogens. We further conducted inductively coupled plasma mass spectrometry to confirm that the Ag+ ions released from these nanocomposite films did not exert adverse effects on the human body. These results suggested that, when applied to stainless steel orthodontic appliances, these durable antifouling and antibacterial coatings may be useful for avoiding bacterial infection.

The new class of multiwalled carbon nanotube (MWCNT)/titania nanocomposites was prepared using a sol-gel technique. The addition of titania to MWCNTs has the potential to provide new capability for the development of electrical devices by taking advantage of the favorable electric characteristics of MWCNTs. MWCNTs were first functionalized with carboxyl, acyl chloride, amine, and hydroxyl groups and were then dispersed in a tetraisopropyl titanate (TIPT) solution via ultrasonic processing. After gelation, well-dispersed titania in the MWCNT/titania nanocomposites was obtained. Functionalized MWCNTs with varied functional groups were proved by Fourier transform infrared spectroscopy (FT-IR). For the nanocomposites, the degree of the sol-gel process were proved by Raman spectroscopy and wide-angle X-ray diffraction (WAXD). Furthermore, the morphology of the MWCNT/titania nanocomposites was observed using transmission electron microscopy (TEM). In the sol-gel process, the functionalized MWCNTs with carboxyl, acyl chloride, amine, and hydroxyl groups have resulted in the carbon nanotube-graft-titania nanocomposites with a network structure of titania between the carbon nanotubes.

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