Synthesis of Water-Soluble Imidazolium Polyesters as Potential Nonviral Gene Delivery Vehicles

Abstract

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.

Effect of Poly(ethylene glycol) Crystallization on Ionic Conduction and Dielectric Response of Imidazolium-Based Copolyester Ionomers

“…In addition to these efforts, new attention has been paid to the development of PIL ionenes that possess regular IL units (e.g., ammonium, imidazolium, and phosphonium) along the main chains, not only enabling an easy control of the reactivity and total ion concentration but also allowing for uniform microphase separation, via a step growth polymerization. − Wagener and co-workers reported the synthesis of imidazolium-based ionenes with precisely functionalized imidazolium moieties in the polymer backbones via acyclic diene metathesis (ADMET) polymerization. The synthesized ionenes exhibited microphase-separated morphologies, where most of ion dipoles were immobilized or had net antiparallel arrangements in ion aggregates, yielding a strong polymer film with a rubbery plateau, but with a rather low ionic conductivity .…”

Thioimidazolium Ionic Liquids as Tunable Alkylating Agents

“…Ionic liquids (ILs) serve as a platform to design countless chemical structures with a broad range of chemical, physical, and functional properties. The designer nature of ILs is key to their implementation for specific functions or applications, including extractions, solvents, − polymers, electrolytes, therapeutics, and many more . Despite these examples, one function that has not been introduced is the ability to alkylate, where the IL can selectively transfer one of its alkyl groups under mild conditions.…”

Preparation and photochromic properties of waterborne polyurethane containing spirooxazine groups

“…Polyurethane (PU) is an organic polymer material whose structure can be designed, and it has extensive applications in various fields because of its excellent performance, such as in coatings, adhesives, foams, elastomers, and fibers . However, solvent polyurethanes with high volatile organic compound (VOC) content do not conform to the trend toward green chemistry .…”