A critical obstacle and challenge for cancer therapy is the limited availability of effective biocompatible delivery systems. Since many effective anticancer agents have poor water solubility, the development of novel delivery systems for these molecules without the use of organic solvents has received significant attention.
Camptothecin (CPT) and its derivatives are considered to be among the most effective anticancer drugs of the 21st century. Although studies have demonstrated their effectiveness against carcinomas of the stomach, colon, neck and bladder, as well as against breast cancer, small-cell lung cancer and leukemia in vitro, clinical application of CPT in humans has only been carried out with CPT derivatives that have improved water solubility.
In order to be used on humans, current cancer therapies such as CPT or Taxol, which are poorly water soluble, must be mixed with organic solvents in order to be delivered into the body, Tamanoi said. These elements produce toxic side effects and in fact decrease the potency of the cancer therapy.
To overcome these problems, drug delivery systems using pegylated polymers, liposomal particles or albumin-based nanoparticles have been developed.
The new research findings show that mesoporous silica nanoparticles offer great potential and a promising approach to the delivery of therapeutic agents into targeted organs or cells. The pores in the nanoparticles could be closed by constructing an appropriate cap structure. This provides the ability to control the release of anticancer drugs by external stimuli.