A new cell membrane stationary phase (CMSP) consisting of porous silica coated with active cell membranes is presented for affinity chromatography. By immersing silica into a suspension of cell membranes, the whole surface of silica was covered by the cell membranes due to the irreversible adsorption of silanol groups (Si-OH) on the silica surface and the self-fusion of the cell membranes. CMSP can be used directly as a chromatographic packing material without any additional chemical modification. The surface characteristics, enzymatic activity, and chromatographic behavior of CMSP were investigated. The results obtained from scanning electron microscope, surface energy spectrometer, enzyme assay, and liquid chromatography showed that the surface characteristics of CMSP were very different from that of normal and reversed stationary phases. CMSP was found to have the characteristics of both cell membrane activity and chromatographic separation. Moreover, CMSP, as a chiral stationary phase, could be used for the enantiomeric separation of (• Bay-K8644. The capacity factor of some calcium antagonists on CMSP was found to have a good correlation with their pharmacological actions. It is concluded that CMSP may be used not only as a kind of packing material in bio-affinity chromatography, but also as a tool for studying the interactions bef,,veen a drug and its receptor.Original 0009-5893/00/02

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Crystallization behavior of calcium carbonate (CaCO 3 ) in water/ethanol mixed solutions under ambient conditions using polystyrene sulfonate (PSS) as a crystal growth modifier has been systematically investigated. The results have demonstrated that a switch from thermodynamic control to kinetic control in the crystallization process of CaCO 3 can be easily realized by adding ethanol, which can have a significant influence on the polymorphs and morphologies of CaCO 3 crystals. Calcite mesocrystals and vaterite complex aggregates with increasingly developed shapes can be obtained with an increase of the ethanol content in the solution. The polymorph change of CaCO 3 crystals from pure calcite to a calcite dominated mixture and finally to a vaterite dominated mixture has also been nicely captured. Both CaCO 3 crystals with different evolving phases and the polymorph change of CaCO 3 from calcite to vaterite can be attributed to the balance between thermodynamic control and kinetic control in this special crystallization media. This work sheds light on the possibility of adding ethanol to control the kinetic/thermodynamic balance and thus to possibly control the morphologies and polymorphs of a wide range of inorganic materials.