Mesoporous silica nanoparticles as potential carriers for enhanced drug solubility of paclitaxel

In this study, paclitaxel (PTX), a typical chemotherapeutic agent with poor water-solubility, was selected as the model drug to evaluate the feasibility of mesoporous silica nanoparticles (MSN) to load a hydrophobic drug in different solvents. A sol-gel method was used to synthesize MSN. Drug loading was carried out in three different solvents: dichloromethane, ethanol and dimethyl sulfoxide (DMSO) via a solvent evaporation method, and their effects on drug loading were examined. We further studied the effects of drug loading period and mass ratio of drug to carrier on drug loading capacity of MSN, as well as the in vitro drug release was analyzed. Moreover, the cytotoxic effect of PTX loaded MSN on liver carcinoma (HepG2) cells was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The related materials were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), dynamic light scattering (DLS), fourier transform infrared spectrometer (FTIR), small-angle x-ray scattering (SAXS), wide-angle x-ray diffraction (XRD) and N₂ adsorption-desorption analyses. The results demonstrated a highly improved solubility of PTX by using MSN as drug carriers compared to free PTX. In addition, drug loading content increased as the solvent polarity parameter decreased or the drug/carrier mass ratio increased. Compared with the blank MSN, the PTX loaded MSN could produce a significant cytotoxicity on HepG2 cells. Our results indicated that MSN could be very potential drug delivery carriers for poorly water soluble drugs.