POS8-1196
Influence of Branched Molecular Architecture on Polyion Complex Stability under Reduced Net Charge Conditions
Topic
S8. Frontiers of Functional Polymers in Biology and Medicine
When and Where
Sep 30, 2026
08:30 - 09:30
Room 301 (Grand Ballroom)
Session Chairs
Heesuk KIM
Jinhye BAE
Presenter(s)
Masayuki Nakashoya (Graduate School of Medical Science, Kyoto Prefectural University of Medicine)
Co-Author(s)
Abstract
Branched polyelectrolytes are likely to make more stable polyion complexes (PICs) than linear polyelectrolytes. However, branched structures often accompany larger molecular weights and greater overall charges leading to stronger electrostatic interaction with the oppositely charged counterparts. Consequently, the intrinsic contribution of molecular architecture to PIC stability has not been well understood. In addition, polyelectrolytes are typically strongly charged, so that the subtle effects of architecture may be obscured by the dominant contribution of electrostatic interactions.
To address this issue, we designed a series of polyelectrolytes derived from a diamine-based polyzwitterion [PGlu(DET-Car)], in which the number of arms is systematically varied whereas the overall charge and chemical composition are identical. The stepwise protonation behavior of the diamine moiety enables the weakly net cationic charges in the zwitterionic side chains at pH 6.0–7.0. Therefore, the contribution of net charge is minimized, permitting the subtle effects of molecular architecture to be resolved. This experimental design enabled us to examine how molecular architecture governs PIC formation independently of overall charge.
Through a combination of physicochemical and biological characterization, we demonstrate that branched PGlu(DET-Car)s markedly enhance interactions with flexible polyanions and anionic cell surfaces, regardless of the molecular weights and overall charges comparable to those of the linear analogue. Moreover, branched architecture formed PICs even in the presence of elevated salt concentrations, whereas PICs prepared from linear PGlu(DET-Car) were dissociated under the same conditions, further confirming the essential role of the branched architectures for stable PIC formation. Altogether, these results suggest that molecular architecture serves as a design rationale to tune the PIC stability independent of overall charges.
To address this issue, we designed a series of polyelectrolytes derived from a diamine-based polyzwitterion [PGlu(DET-Car)], in which the number of arms is systematically varied whereas the overall charge and chemical composition are identical. The stepwise protonation behavior of the diamine moiety enables the weakly net cationic charges in the zwitterionic side chains at pH 6.0–7.0. Therefore, the contribution of net charge is minimized, permitting the subtle effects of molecular architecture to be resolved. This experimental design enabled us to examine how molecular architecture governs PIC formation independently of overall charge.
Through a combination of physicochemical and biological characterization, we demonstrate that branched PGlu(DET-Car)s markedly enhance interactions with flexible polyanions and anionic cell surfaces, regardless of the molecular weights and overall charges comparable to those of the linear analogue. Moreover, branched architecture formed PICs even in the presence of elevated salt concentrations, whereas PICs prepared from linear PGlu(DET-Car) were dissociated under the same conditions, further confirming the essential role of the branched architectures for stable PIC formation. Altogether, these results suggest that molecular architecture serves as a design rationale to tune the PIC stability independent of overall charges.
