Structure of asymmetrical peptide dendrimers : Insights given by self-consistent field theory

Structural properties of asymmetric peptide dendrimers up to the 11th generation are studied on the basis of the self-consistent field Scheutjens-Fleer numerical approach. It is demonstrated that large scale properties such as, e.g., the gyration radius, are relatively weakly affected by the asymmetry that is, by difference in the length of short and long spacers. However, the asymmetry has strong influence on the internal structure of the dendrimers and on the radial distribution of polymer density and terminal segments. In particular, symmetrical and weakly asymmetrical dendimers are characterized by quasi-uniform intramolecular concentration profiles of monomer units whereas strongly asymmetric dendrimers are characterized by sharply decreasing in a radial direction polymer density profile reminiscent to that in star-shaped polymers. This finding may have important implication for the use of peptide dendrimers as carriers for biologically active molecules