Release behavior, kinetic and antimicrobial study of nalidixic acid from [Zn2(bdc)2(dabco)] metal-organic frameworks

In the present study, a hydrothermal method was developed to prepare nalidixic acid-loaded [Zn₂(bdc)₂(dabco)] metal–organic frameworks. The self-assembly of primary building blocks was used for synthesis of [Zn₂(bdc)₂(dabco)] at room temperature. The zinc metal ion was used as a connector, 1,4-benzenedicarboxylate (bdc) as a chelating ligand, and 1,4-diazabicyclo[2.2.2]octane (dabco) as a bridging ligand. The metal organic frameworks were used as the carriers for drug delivery system, where it could entrap nalidixic acid as a model drug. X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), ultraviolet-visible spectroscopy (UV–vis), BET nitrogen adsorption–desorption method, and scanning electron microscopy (SEM) were used for characterization of samples. The drug release was also monitored, and 96 and 62% of the loaded drug were released over 120 h at pH values of 5.0 and 7.4, respectively. The antimicrobial activities of [Zn₂(bdc)₂(dabco)] and nalidixic acid-loaded [Zn₂(bdc)₂(dabco)] were tested against Gram-positive and Gram-negative species. The results revealed that this nanoscale metal organic framework may be regarded as a simple and stable platform for drug release in the treatment of infectious diseases.