Functionalized phosphorylated cellulose microspheres: Design, characterization and ciprofloxacin loading and releasing properties

In this work, functionalized phosphorylated cellulose microspheres (CMP) were designed as a carrier for the ciprofloxacin (CIP) drug delivery system. The CMP has been developed from cellulose microspheres (CM) and phosphoric acid via an esterification reaction. CIP, an antibiotic drug as a model, was loaded onto CIP via hydrogen bonds and electrostatic interactions. A series of test results showed that the CIP was successfully incorporated and released from the prepared CMP without the loss of structural integrity or changing its functionality. The release kinetics and mechanism suggest that CIP release follows first-order kinetics and non-Fickian diffusion mechanism. The cytotoxicity behavior of CMP enables the material as a suitable vehicle for the safe release of CIP. The CIP loaded microspheres exhibited a significant antibacterial effect due to the CIP release and diffusion from the microspheres. This study provides insight into the design of suitable cellulose microspheres for CIP delivery.