ARS | Publication request: A COMPARISON BETWEEN DENDRITICALLY BRANCHED MACROMOLECULES AND LINEAR POLYSACCHARIDES: SEC, MS, AND COMPUTER MODELING

Submitted to: International Gel Permeation Chromatography Symposium
Publication Type: Abstract Only
Publication Acceptance Date: October 7, 1998
Publication Date: N/A

Technical Abstract: Dendritic macromolecules, or dendrimers, a relatively new class of synthetic polymers are, theoretically, the most highly branched structures achievable. Their numerous potential uses extend to being drug-delivery carriers, chromatographic support media, and NMR contrast agents. They may also serve as models for hyperbranched synthetic and natural polymers, an example of the latter being the polysaccharide amylopectin, a high- molecular weight component of many types of starches. In this initial study we compare the solution behavior of Starburst (registered trademark) polyamidoamine dendrimers, as determined utilizing size exclusion chromatography (SEC), to that of low-molecular weight linear dextrans and maltodextrins of equivalent molar mass. Contrasting intrinsic viscosities and molecular weight distributions allows observation of the much narrower polydispersities of the dendrimers with respect to their linear poly- saccharide counterparts, with the intrinsic viscosities of the former maintaining a consistently lower value throughout the range of the distribution. Where dissolution of the dendrimers proved difficult [e.g., for Astramol (registered trademark) dendrimers] mass spectrometric characterization was performed using electrospray ionization mass spectrometry (ESI-MS) with linear quadrupole and quadrupole ion trap mass analysis. Size studies were performed by comparing radii obtained by computer modeling, SEC, and literature values.