Original scientific paper

Microscopic Protonation Mechanism of Branched Polyamines: Poly(amidoamine) versus Poly(propyleneimine) Dendrimers*

Duško Čakara ; Laboratory of Physical Chemistry, Department of Chemistry, Faculty of Science, University of Zagreb, Zagreb, Croatia
Michal Borkovec ; Department of Inorganic, Analytical, and Applied Chemistry, University of Geneva, Geneva, Switzerland

Abstract

The protonation mechanisms of the poly(amidoamine) (PAMAM) andpoly(propyleneimine) (PPI)
dendrimers are clarified and related to their molecular structure. The overall proton binding
isotherms can be interpreted in terms of a site binding model, which involves a limited number
of parameters, and can be used to gain detailed insight in both macroscopic and microscopic
protonation mechanisms. The protonation of the PAMAM dendrimers is dominated by the
chemical environment of the amine sites, and the sites protonate almost independently leading
to protonation mechanism with a characteristic intermediate core-shell structure. In the case of
PPI, the protonation is dominated by the electrostatic nearest-neighbor repulsions between the
protonated sites, and leads to an intermediate »onion-like« structure where all the odd shells
are protonated.

Keywords

dendrimer; polyamine; protonation; mechanism; PAMAM; PPI; hyperbranched; polyelectrolyte; gene vector; transfection

Hrčak ID:

18665

URI

https://hrcak.srce.hr/18665

Publication date:

30.11.2007.

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