Rattle-Type Mesoporous Silica Nanoparticles Could Enhance the Delivery of Cancer Drugs

Advancing the use of silica nanomaterials for in vivo cancer therapy, a team of scientists headed by Fangqiong Tang, a chemistry professor at the Technical Institute of Physics and Chemistry, Chinese Academy of Sciences (Beijing), has shown that silica nanorattles can enhance the effectiveness of in vivo drug-delivery therapy while reducing the toxicity of antitumor drugs.

As detailed in ACS Nano, the researchers chose elaborately designed silica nanorattles with a mesoporous and hollow structure as the carrier of an antitumor drug for liver cancer therapy. In addition to their mesoporous and hollow structure, the nanoparticles can enhance cancer drug-delivery therapies because they include amino groups on their surface, facilitating surface functionalization and bioconjugation with biomolecules; have a controllable size and narrow size distribution; and have the ability for large-scale synthesis.

The team loaded the hydrophobic antitumor drug docetaxel into synthesized 125-nm silica nanorattles up to a concentration of 32%. Investigating the cumulative drug release, the scientists discovered that the delivery system exhibited a low initial burst release within 60 minutes followed by rapid release in 0 to 20 hours--attributed to the drug's weak interaction on the outside of the silica nanorattles--and lower release from 20 hours to five days--attributed to the drug's electrostatic absorbtion into the mesopores and its location in the hollow spaces of the silica nanorattles.

The researchers also found that even with a tested concentration range as high as 1 mg/mL, the nanorattles had no obvious adverse effect on cell viability, demonstrating their noncytotoxic properties.

The nanorattles, according to Tang, have the potential to act as a versatile and robust drug-delivery platform for accommodating a variety of drugs. The team intends to experiment with silica nanorattles as nanocarriers for other drugs. They are also planning to research the nanorattles' intracellular transport capabilities and biological effects, in addition to designing strategies for using the nanorattles for multistage drug-delivery and drug/drug or drug/gene codelivery applications.

More information on this research can be obtained from Nanowerk.