Ultrasonic Preparation of Nano-CaCO Templates and Hollow Mesoporous SiO Nanoparticles for Voriconazole Loading.

CaCO nanoparticles (nano-CaCO) as nano-templates were prepared using CaCl and NaCO solutions under controlled sonication (19.5 kHz). Using the same ultrasonic device, subsequently, hollow mesoporous silica nanoparticles (HMSNs) were obtained by the hard template of nano-CaCO. HMSNs were selected as carriers for the antifungal drug voriconazole (VOR) loading to overcome poor water solubility. Three-dimensional CaCO nanosheets HMSNs were obtained under gentle sonication. Three-dimensional CaCO nanosheets of 24.5 nm (hydrodynamic diameter) were obtained under 17.6 W for 3 min. HMSNs were synthesized by double-template method with nano-CaCO as the hard template. Transmission electron microscopy measurements showed that the prepared HMSNs possess hollow structures with particle size between 110 and 120 nm. Nitrogen physisorption at -196 °C revealed that the HMSNs had high surface area (401.57 m/g), high pore volume (0.11 cm/g), and uniform pore size (2.22 nm) that facilitated the effective encapsulation of VOR in the HMSNs. The loading capacity of VOR (wt%) on the HMSNs was 7.96%, and the total VOR release amount of VOR-HMSNs material was 71.40% at 480 min. The kinetic model confirmed that the release mechanism of HMSNs nanoparticles followed Fickian diffusion at pH = 7.4 and 37 °C. Moreover, the cumulative VOR release at 42 °C (86.05%) was higher than that at 37 °C (71.40%). The cumulative release amount of VOR from the VOR-HMSNs material was 92.37% at pH = 5.8 at the same temperature. Both nano-CaCO templates and HMSNs were prepared by sonication at 19.5 kHz. The as-prepared HMSNs can effectively encapsulate VOR and released drug by Fickian diffusion.