Preparation Of Mesoporous Silica Microspheres With Multi-Hollow Cores And Applications

Mesoporous silica microspheres with multi-hollow cores (MSMMCs) were prepared by an O1/W/O2 double emulsion technique. When TEOS was hydrolyzed in an O1/W/O2 double emulsion with polymer P123 dissolved in the aqueous phase, the internal oil droplets would serve as templates for the empty hollow cores, P123 would function as templates for the mesopores in the shell, and the aqueous phase would act as space-limiting micro-reactors for the hydrolysis process, thus forming MSMMCs with controllable size and hollow cores. The prepared MSMMCs had a diameter of 2-10μm, macro multi-hollow cores with a size of 200-1200 nm, mesopores in the shell with a size of 3.8-4.4 nm, and a surface area of 232-351.7 m2/g. For application, MSMMCs were used as carriers to load avermectin through an immersing and evaporating process, and the loaded avermectin showed a well sustained release behavior from the MSMMCs matrix. In addition, oil-soluble ibuprofen and water-soluble vitamin C were loaded in-situ in MSMMCs simultaneously during the synthesis process of MSMMCs, and the release of both drugs could last for thousands of minutes.This study demonstrated a promising and simple method for preparing silica micro-particles with porous multi-hollow core structure for sustained release applications.