Synthesis of spherical and hemispherical sugar-containing poly(ornithine) dendrimers

A novel sugar-containing poly(ornithine) dendrimer is synthesized for possible antigen delivery and related applications. The dendrimer contains an ornithine dendron as interior scaffolding and oligosaccharides on the periphery, which provide an attachment site for a peptide antigen. Maltose or lactose is bound to both hemispherical and spherical poly(ornithine) dendrimer generation 3 (G3) by reductive amination between its reducing end and the peripheral amino group of the dendrimer using a borane-pyridine complex in a buffer solution at 50 degreesC. The degree of substitution of sugar is changed by varying the molar ratio of sugar to dendrimer. When the surface of spherical poly(ornithine) dendrimer G3 is modified by binding beta-alanine to the 16 amino groups, highly substituted maltose- or lactose-beta-alanine-poly(ornithine) dendrimer G3 is obtained in high yield after 7 days of reaction. The structures of these sugar-containing dendrimers are characterized by NMR and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analyses. (C) 2004 Wiley Periodicals, Inc.