Synthesis and characterization of hyperbranched polyesters from polyethylene glycol and citric acid: structural insights and antibiotic resistance mitigation against drug-resistant bacterial strains†

Abstract

The escalating global threat of microbial diseases and antibiotic resistance has spurred research into innovative polymeric materials with potent antimicrobial properties, driven by the impact on healthcare systems worldwide and the increasing resistance of conventional drugs. Multidrug-resistant (MDR) bacteria pose a significant challenge to global health, endangering vulnerable patients and critical medical procedures, with profound economic implications. Addressing antibiotic resistance requires a multifaceted approach, including exploring new drug formulations like natural and hyperbranched polymers. A promising strategy involves combining synthetic hyperbranched polymers with existing drugs to eliminate resistant cells and impede biofilm formation more effectively within a shorter timeframe, offering a cost-effective alternative for treating antibiotic-resistant infections. Innovative polyesters derived from polyethylene glycol and citric acid show potential as nanoscale antibiotics due to their biocompatibility, biodegradability, and antibacterial activity. With this as the context, our study aims to synthesize hyperbranched polyesters by controlling gelation and optimizing branching with strategic adjustments of citric acid mole composition relative to PEG. It was also found that antimicrobial studies revealed the efficacy of these polyesters against Gram-positive and Gram-negative bacteria, particularly in specific formulations. We envision that combining sublethal doses of these polyesters with conventional antibiotics resulted in synergistic effects, enhancing antimicrobial activity and biofilm eradication without promoting resistance development.