Zirconium-based MOFs as pH-responsive drug delivery systems: encapsulation and release profiles of ciprofloxacin

As antimicrobial resistance (AMR) continues to rise, the need for improved antibiotic delivery systems is urgent to prevent overexposure from systemic administration. To address this clinical trial, metal-organic frameworks have developed as promising contender for regulated drug release. In this study, ciprofloxacin (CIP) was encapsulated into two zirconium-based MOFs (ZrMOF-1 and Zr-MOF-2), synthesized via a previously reported solvothermal method. Comprehensive characterization was performed using FTIR, PXRD, SEM, and BET analysis confirming their crystallinity and porosity. The MOFs structure integrity was maintained even after drug loading, ensuring stability. Ciprofloxacin release profiles were monitored via UV-Vis spectroscopy, revealing that MOF-2 exhibited more controlled and sustained release over seven days in a basic medium (pH 9.2). A pH-responsive release behavior was observed, with accelerated drug release in basic conditions, suggesting a tunable release mechanism. These findings confirm that Zr-MOF@CIP is a potential biocompatible material for drug delivery systems, warranting further in vivo studies for applications in medical science and pharmaceutics. © 2025 Elsevier B.V., All rights reserved.