Cover Picture: Biomimetic Fluorapatite–Gelatine Nanocomposites: Pre‐Structuring of Gelatine Matrices by Ion Impregnation and Its Effect on Form Development / Intrinsic Electric Dipole Fields and the Induction of Hierarchical Form Developments in Fluorapatite–Gelatine Nanocomposites: A General Principle for Morphogenesis of Biominerals? (Angew. Chem. Int. Ed. 12/2006)

Abstract

Form development during growth of fluorapatite-gelatine nanocomposites is effected by pre-structuring of gelatine matrices by ion impregnation. The cover picture shows the hierarchical fractal aggregate (background), structural details of a fanlike aggregate, and a simulation of the "stiffening" effect on a protein molecule of Ca 2þ ion incorporation. This effect is discussed by R. Kniep and co-workers in their Communication on page 1905 ff. A second paper on page 1911 ff. deals with the effect of intrinsic electric dipole fields on the form development of the nanocomposite materials. Reactivity and SelectivityIn their Minireview on page 1844 ff., H. Mayr and A. R. Ofial challenge the widely accepted reactivity-selectivity principle for organic reactions: Reactivity and selectivity of a species should exhibit opposite behavior-but its not as easy as it sounds! Nanoscience DNA molecules are excellent building blocks for the construction of complex superstructures. Construction principles as well as possible applications of such assemblies are described by U. Feldkamp and C. M. Niemeyer in their Review on page 1856 ff. Photoresponsive MaterialsA first step towards the design of intelligent delivery vehicles is presented by S. Hecht and co-workers in their communication on page 1878 ff., which describes the unfolding of the hollow helical secondary structure of a foldamer upon irradiation.