Development and evaluation of hollow mesoporous silica microspheres bearing on enhanced oral delivery of curcumin

The aim of this work is to develop curcumin-loaded hollow mesoporous silica microspheres (HMSMs@curcumin) to improve the poor oral bioavailability of curcumin. Hollow mesoporous silica microspheres (HMSMs) were synthesized in facile route using a hard template. HMSMs and HMSMs@curcumin were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption/desorption measurements, differential scanning calorimetry (DSC), Fourier transform infrared (FTIR), and X-ray diffraction (XRD). In addition, to demonstrate the potential application of the HMSMs@curcumin, cytotoxicity, in vitro release behavior and in vivo pharmacokinetics of curcumin loaded in these HMSMs were investigated by using of Caco-2 cells and Sprague-Dawley (SD) rats, respectively. These mono-dispersed HMSMs exhibited high drug loading ratio and encapsulation efficiency due to the mesoporous shell and hollow core. The excellent characteristics of HMSMs such as mono-dispersed morphology, smooth surface, uniform, ordered and size-narrowing mesopores resulted in a good in vitro release profile of curcumin from HMSMs@curcumin. Moreover, an impressive improvement in the oral absorption of curcumin and prolonged systemic circulation time were achieved in the in vivo animal studies. In addition, the good biocompatibility of developed HMSMs with Caco-2 cells was confirmed based on the in vitro cytotoxicity assay. In conclusion, this system demonstrated a great potential for efficient delivery of curcumin in vitro and in vivo, suggesting a good prospect for its application in clinic for therapeutic drug delivery in future.