Encapsulation of Amoxicillin within Laponite-Doped Poly(lactic-<i>co</i>-glycolic acid) Nanofibers: Preparation, Characterization, and Antibacterial Activity

We report a facile approach to encapsulating amoxicillin (AMX) within laponite (LAP)-doped poly(lactic-co-glycolic acid) (PLGA) nanofibers for biomedical applications. In this study, a synthetic clay material, LAP nanodisks, was first used to encapsulate AMX. Then, the AMX-loaded LAP nanodisks with an optimized AMX loading efficiency of 9.76 ± 0.57% were incorporated within PLGA nanofibers through electrospinning to form hybrid PLGA/LAP/AMX nanofibers. The loading of AMX within LAP nanodisks and the loading of LAP/AMX within PLGA nanofibers were characterized via different techniques. In vitro drug release profile, antimicrobial activity, and cytocompatibility of the formed hybrid PLGA/LAP/AMX nanofibers were also investigated. We show that the loading of AMX within LAP nanodisks does not lead to the change of LAP morphology and crystalline structure and the incorporation of LAP/AMX nanodisks does not significantly change the morphology of the PLGA nanofibers. Importantly, the loading of AMX within LAP-doped PLGA nanofibers enables a sustained release of AMX, much slower than that within a single carrier of LAP nanodisks or PLGA nanofibers. Further antimicrobial activity and cytocompatibility assays demonstrate that the antimicrobial activity of AMX toward the growth inhibition of a model bacterium of Staphylococcus aureus is not compromised after being loaded into the hybrid nanofibers, and the PLGA/LAP/AMX nanofibers display good cytocompatibility, similar to pure PLGA nanofibers. With the sustained release profile and the reserved drug activity, the organic/inorganic hybrid nanofiber-based drug delivery system may find various applications in tissue engineering and pharmaceutical science.