The development of simple, versatile strategies for the synthesis of metal-organic framework (MOF)-derived membranes are of increasing scientific interest, but challenges exist in understanding suitable fabrication mechanisms. Here we report a route for the complete transformation of a series of MOF membranes and particles, based on multivalent cation substitution. Through our approach, the effective pore size can be reduced through the immobilization of metal salt residues in the cavities, and appropriate MOF crystal facets can be exposed, to achieve competitive molecular sieving capabilities. The method can also be used more generally for the synthesis of a variety of MOF membranes and particles. Importantly, we design and synthesize promising MOF membranes candidates that are hard to achieve through conventional methods. For example, our CuBTC/MIL-100 membrane exhibits 89, 171, 241 and 336 times higher H2 permeance than that of CO2, O2, N2 and CH4, respectively.

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Colloidal particles with polystyrene (PS) cores and gold nanoparticle (AuNP) coronae were prepared on the basis of the self-assembly of AuNP's and PS. Citrate-stabilized AuNP's were dispersed in aqueous solution, and PS with thiol terminal groups (PS-SH) was dissolved in toluene. A stable emulsion was obtained by mixing the two solutions. Optical microscope images indicate that after grafting of PS-SH to the citrate-stabilized AuNP's at liquid-liquid interface, the interfacial tension is reduced and the average size of toluene droplets in the emulsion decreases. Transmission electron microscope (TEM) results also prove the grafting of PS-SH to AuNP's and the location of the hybrid nanoparticles at the liquid-liquid interface. Colloidal particles with PS cores and AuNP coronae were prepared by adding the emulsion to excess methanol. The weight ratio of PS-SH to AuNP exerts a significant effect on the size of colloidal particles. TEM and dynamic light scattering results both indicate that the size of colloidal particles increases with the weight ratio. The application of the core-shell-structured colloidal particles to protein separation was also investigated in this research. Colloidal particles with PS-coated magnetic nanoparticles in the cores were also prepared by this strategy.

Abstract. In order to develop a novel transdermal drug delivery system that facilitates the skin permeation of finasteride encapsulated in novel lipid-based vesicular carriers (ethosomes)finasteride ethosomes were constructed and the morphological characteristics were studied by transmission electron microscopy. The particle size, zeta potential and the entrapment capacity of ethosome were also determined. In contrast to liposomes ethosomes were of more condensed vesicular structure and they were found to be oppositely charged. Ethosomes were found to be more efficient delivery carriers with high encapsulation capacities. In vitro percutaneous permeation experiments demonstrated that the permeation of finasteride through human cadaver skin was significantly increased when ethosomes were used. The finasteride transdermal fluxes from ethosomes containing formulation (1.34±0.11 μg/cm 2 /h) were 7.4, 3.2 and 2.6 times higher than that of finasteride from aqueous solution, conventional liposomes and hydroethanolic solution respectively (P<0.01).Furthermore, ethosomes produced a significant (P<0.01) finasteride accumulation in the skin, especially in deeper layers, for instance in dermis it reached to 18.2±1.8 μg/cm 2 . In contrast, the accumulation of finasteride in the dermis was only 2.8± 1.3 μg/cm 2 with liposome formulation. The study demonstrated that ethosomes are promising vesicular carriers for enhancing percutaneous absorption of finasteride.