Chiral mesoporous silica based LOFL delivery systems using achiral alcohols as co-structure-directing agents: Construction, characterization, sustained release and antibacterial activity

Abstract

The present work reported two synthesized chiral mesoporous silicas (CMSs) with opposite chirality for loading, release, and antibacterial activities of levofloxacin (LOFL). Herein, helical CMS nanorods were prepared by the sol-gel method using CTAB as a template and either n-heptanol or n-nonanol as a co-structure-directing agent (CSDA). The synthesized CMSs were characterised by transmission electron microscopy (TEM), small-angle X-ray scattering (SAXS), induced circular dichroism (ICD), and nitrogen adsorption/desorption. X-ray diffraction (XRD) was applied to confirm amorphous state transformation after drug loading, and thermal gravimetric analysis (TGA) was used to quantify the LOFL loading capacity. In vitro drug release studies from the loaded CMSs showed significant differences in the release behaviour for LOFL. Moreover, LOFL-loaded CMSs significantly sustained LOFL release with Fickian diffusion mechanism. Both the drug-loaded CMSs inhibited bacterial growth successfully when tested with strains of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Therefore, the prepared CMSs could find application as suitable vehicles for drug delivery systems to exert the therapeutic effects of LOFL and achieve different release behaviours.