Acetazolamide-Loaded Nanoparticle Based on Modified Hyaluronic Acid as Delivery System to Target Carbonic Anhydrases in Escherichia coli

Acetazolamide (AZA) is a validated carbonic anhydrase inhibitor (CAI) that has the potential for use in various therapeutic applications. Herein, we report a novel AZA-loaded biodegradable nanodelivery system that was proven to enhance the antibacterial efficacy of the drug against Gram-negative bacteria, such as Escherichia coli. Carbonic anhydrases (CA, EC 4.2.1.1) in E. coli play a crucial role in bacterial metabolism and CO2/HCO3− balance; therefore, they represent a suitable target for antimicrobial strategies. The nanoparticles were obtained using a green synthetic protocol that allowed conjugation of a natural fatty acid to hyaluronic acid (HA) under solvent-free conditions. Full characterization of the micellar aggregates was performed (diameter of the micelles, zeta potential, and drug release study). In vitro studies demonstrated that AZA loaded in HA-based nanoparticles significantly inhibited E. coli growth at concentrations as low as 0.5 µg/mL, whereas higher concentrations of free AZA were required, as previously reported. Additionally, encapsulated AZA disrupted glucose consumption in E. coli, indicating its profound impact on bacterial metabolism. These findings suggest that the HA–palmitate nanoparticle not only enhances the delivery and efficacy of AZA but also offers a strategy to affect bacterial metabolism.