Graft Polymers Derived from Pharmaceutically Active Choline-Based Ionic Liquid Monomers: Dual Incorporation of Ampicillin and Cloxacillin

This study reports the synthesis and characterization of well-defined ionic graft conjugates acting as drug delivery systems, based on monomeric ionic units derived from choline methacrylate (TMAMA) biofunctionalized with the anions of ampicillin (AMP) or cloxacillin (CLX). Using the "grafting from" technique with multifunctional macroinitiators, the density of side chains was precisely defined, and the length of side chains was well-controlled during polymerization. The resulting ionic conjugates featured the regulated content of ionic fractions with drug anions reaching up to 55% and drug content up to 48-70% for AMP, 27-65% for CLX, and 47-79% for (CLX + AMP). The drug release behavior was evaluated under physiological conditions using a dialysis method. The ionic conjugates demonstrated release efficiencies of 70-93% for CLX (5-16 µg/mL), 69-98% for AMP (12-13 µg/mL) in single systems, and 61-73% for CLX + AMP (10-15 µg/mL) in dual systems. Additionally, polymer surface properties were evaluated via water contact angle measurements (WCA = 30-54°). In an aqueous solution, the polymer self-assemblies appeared to be nanosized particles (90-360 nm). The results demonstrate that the synthesized TMAMA-based graft copolymers act as effective ionic conjugates and dual drug systems, offering a promising platform for controlled and multi-drug delivery applications.