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Restenosis, the re-narrowing of a blood vessel after removal of atherosclerotic plaque, is a major limitation of surgical treatments for atherosclerosis. Various attempts to prevent or treat restenosis by pharmacological or mechanical approaches have had limited success in clinical trials. Hence, there is wide interest in developing new strategies to prevent or treat restenosis. This review discusses ‘a new-generation therapy’ that uses functional nanoparticles to effectively deliver active drug molecules. The potential platforms for nanoparticle-based solutions to restenosis include organic (e.g. polymers, liposomes, and proteins) and inorganic nanoparticles (e.g. layered double hydroxides, titanium oxide nanotubes, and magnetic nanoparticles,). Many in vitro and in vivo studies based on these platforms demonstrate the feasibility and potential of using nanoparticle drug delivery systems for preventing or treating restenosis, but as yet few have reached clinical trials. It is suggested that using inorganic nanoparticles to target deliver multi-functional drugs will be a promising approach to preventing or treating restenosis.

Ru−Mg−Al hydrotalcite-like anionic clay (Mg/Al/Ru 90:29:1) was successfully prepared with a constant-pH coprecipitation method. Calcination of a hydrotalcite-like precursor at 600 °C in the air gave rise to the well-mixed oxide Ru−Mg−Al−O that possesses a good dispersion of Ru species. Ru−Mg−Al−O catalyst after suitable pretreatment exhibits quite high NOxstorage capability in the temperature range of 250−400 °C, and the highest NOxstorage capability of about 220 mol g-1is obtained at 350 °C with flowing 790 ppm NO and 8% O2in N2stream. Meanwhile, the decomposition of 25−60% NO to N2as well as N2O is clearly observed on the catalyst at 300−400 °C. In situ diffuse reflectance Fourier transform (DRIFT) spectra indicate that NOxis adsorbed and stored on a catalyst mainly in the form of various coordinated nitrites/nitrates. On the basis of the NOxadsorption−desorption profiles as well as the in situ DRIFTS spectra, we have proposed a schematic outline for NOxstorage and NO decomposition. Finally, the reduction of stored NOxspecies on the catalyst by H2was carried out at 350 °C, indicating that all adsorbed NOxspecies can be readily reduced by hydrogen.

Layered double hydroxides (LDHs) Mg:Al 2:1 intercalated with straight-chain hydrocarbon sulfonates have been synthesized by anion exchange and characterized by powder XRD, FTIR, and elemental (C,H and metals) analysis. We find that the interlayer spacing of these LDHs can be explained by an interpenetrating packing model with the hydrocarbon chain tilting at an angle of ∼55° to the metal hydroxide layers. When two such sulfonate anions differ by only one methylene group, their simultaneous intercalation results in a single uniform LDH phase, in which the interlayer spacing varies linearly with the ratio between the two anions. In competitive intercalation experiments, the longer-chain sulfonate is preferentially or even exclusively intercalated. Semiquantitative analysis shows that the affinity of C8H17SO3-(or C7H15SO3-) for LDH is ∼6 kJ mol-1stronger than that of C7H15SO3-(or C6H13SO3-). We attribute this increase to an increase in hydrophobic interactions between hydrocarbon chains. Hence, we estimate that the total contribution of hydrophobic interactions between hydrocarbon chains to the affinity of C8H17SO3-for Mg2Al−LDH is around 40−50 kJ mol-1.

The interconversion and decomposition of furan-2(3H )- and -2(5H )-one and their methylated derivatives were studied by following the changes in their photoelectron spectra during pyrolysis. Interconversion occurred at 300–400 4;°C and decomposition at around 600 4;°C giving CO and acrolein as the only products for the unsubstituted furanones. The experimental results suggest that decarbonylation takes place through the 2(3H ) form as the common precursor.