Work

Degradable Cationic Polyesters with Tunable Anion-Induced Upper Critical Solution Temperature Coacervation

Year: 2026

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide Herein, we report degradable cationic polyesters combining pH responsiveness with tunable, anion-induced UCST phase behavior in aqueous media under mildly acidic and physiologically relevant pH conditions, accompanied by reversible self-coacervation. These main-chain polyesters feature ionizable amine side groups paired with Cl – (PE-Cys-Cl) or BF 4 – (PE-Cys-BF 4 ) counterions, enabling UCST transitions triggered by NaCl, NaBF 4, and notably by the pharmaceutically relevant anion salicylate (SAL). Cloud point temperature was tuned over a broad range of 8–91 °C by controlling anion type, pH, polymer concentration, and the anion-to-cation repeat unit ratio (A/CRU). Mechanistic studies revealed liquid–liquid phase separation into dynamic, water-rich coacervate droplets. Importantly, the hydrolytic degradation was strongly counterion-dependent, with PE-Cys-Cl exhibiting substantial degradation under physiological conditions compared to low-molecular-weight PLLA, whereas the more hydrophobic PE-Cys-BF 4 polymer remained largely unchanged. These materials provide a versatile proof-of-concept platform for anion-triggered UCST phase separation, opening opportunities in responsive coacervation, anion sensing, and drug delivery related applications.

Source: Biomacromolecules

DOI: 10.1021/acs.biomac.6c00269

Authors: Maria Kaliva, Maria Karouzou, Maria Vamvakaki

Institutions: University of Crete, Foundation for Research and Technology Hellas

Language: English

Topic: Advanced Polymer Synthesis and Characterization

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,500

Funders: Hellenic Academic Libraries Link, University of Crete, Hellenic Foundation for Research and Innovation