Clindamycin Hydrochloride-loaded Composite Hydrogel of Poly((ethylene glycol) dimethacrylate-glycidyl methacrylate) and Mesoporous Silica Nanoparticles for Bacterial Infection Treatment

Abstract

Two different porous hydrogels with and without mesoporous silica nanoparticles (MSNs) were developed and comparatively evaluated for their potential use in drug delivery applications. The hydrogels were fabricated from the MSNs-mixed and MSNs-free mixtures of poly(ethylene glycol) dimethacrylate, glycidyl methacrylate, poly(vinyl alcohol) (PVA) (porogen), and irgacure-819 (initiator). After UV curing, PVA was leached out with DI water. Then, individual hydrogels were immersed in 0.5 mL of aqueous clindamycin hydrochloride (CDM, 20 mg/mL), mixed with or without simulated body fluid (SBF) used at different ion concentrations, at 37oC for 3 days. The amounts of CDM loaded into and released from each specimen were analyzed by HPLC analysis. The SEM images of the hydrogels revealed porous structures with an average pore size in the range of 148-158 μm. The incorporation of MSNs into the hydrogel slightly increased the amounts of CDM loaded into and released from the specimen, when water was used as drug loading medium. The contents of CDM loaded and released were, however, considerably raised as a function of ion concentration of SBF used, indicating the ionic interactions among CDM, MSNs, and SBF. Furthermore, a more prolonged release of CDM was observed in these composite hydrogels, compared with that of the composite hydrogel loaded with CDM in DI water. Surprisingly, the similar in vitro antibacterial activity up to 7 days was yielded from the composite hydrogels loaded with CDM in DI water and SBF solution, even though the release profiles of CDM observed in these two hydrogels were different, implying that there might be some unreleased CDM left in the hydrogels, which could kill the bacteria. These findings strongly suggested the great potential use of this composite material in antibiotic delivery systems.