The inherent hydrolytic reactivity of polyesters renders them excellent candidates for a variety of biomedical applications. Incorporating ionic groups further expands their potential impact, encompassing charge-dependent function such as deoxyribonucleic acid (DNA) binding, antibacterial properties, and pH-responsiveness. Catalyst-free and solvent-free polycondensation of a bromomethyl imidazolium-containing (BrMeIm) diol with neopentylglycol (NPG) and adipic acid (AA) afforded novel charged copolyesters with pendant imidazolium sites. Varying ionic content influenced thermal properties and offered a wide-range, -41 to 40 °C, of composition-dependent glass transition temperatures (Ts). In addition to desirable melt and thermal stability, polyesters with ionic concentrations ≥15 mol % readily dispersed in water, suggesting potential as nonviral gene delivery vectors. An electrophoretic gel shift assay confirmed the novel cationic copolyesters successfully bound DNA at an N/P ratio of 4 for 50 mol % and 75 mol % charged copolyesters (P(NA-co-ImA) and P(NA-co-ImA)), and an N/P ratio of 5 for 100 mol % Im (PImA). Polyplexes exhibited insignificant cytotoxicity even at high concentrations (200 μg/mL), and a Luciferase transfection assay revealed the ionic (co)polyesters transfected DNA significantly better than the untreated controls. The successful transfection of these novel (co)polyesters inspires future imidazolium-containing polyester design.

Antibodies and antigen binding fragments (FABs) are widely used as therapeutics and conjugated polymers can enhance the properties of these important biomolecules. However, limitations to the selectivity and stability of...