Development of a Bi₂O₃-Modified Chitosan@ZIF-8 Nanocomposite for Optimized Loading and Sustained Release of Antibiotics

Abstract

Chitosan, ZIF-8, a metal-organic framework, and bismuth oxide (Bi2O3) were used to make a new hybrid mesoporous nanocomposite for the study. It was made green and tested to see if it could be used to deliver antibiotics [1]. Electric forces, hydrogen bonds, and π-π interactions were used to show that this Bi2O3-modified chitosan@ZIF-8 nanocomposite could hold and release tetracycline and doxycycline in water [2]. To get a good look at the samples' structure and shape, we used X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) surface analysis, and thermogravimetric analysis (TGA). Key parameters influencing the loading process, including pH, nanocomposite dosage, and contact time, were optimized. Non-linear optimization results indicated that the loading efficiency for both tetracycline and doxycycline exceeded 90% at an initial concentration of 100 mg/L. Optimal loading conditions were identified as pH 4.7, a nanocomposite dose of 1.5 mg/mL, and a contact time of 25 minutes. The nanocomposite with tetracycline and doxycycline released more than 90% of its total amount in phosphate-buffered saline (pH 7.4, T = 37 °C) over 72 hours. These results show it could be a valuable platform for controlled antibiotic delivery.