Nanotech News

September 26, 2005

Self-Assembling Nanoparticles Deliver Poorly Soluble Drugs to Tumor Cells

Many important anticancer drugs, such as paclitaxel, do not dissolve well in water, which makes it difficult to deliver them to tumors given that blood and bodily fluids are mostly water. Nanotechnology has already shown its potential for encapsulating such drugs – the recently-approved nanoparticle drug Abraxane™ is a case in point – and investigators are actively developing a host of nanoparticles with various chemical properties in order to give drug developers a choice of materials for drug formulation efforts.

Adding to that nanoparticle toolbox is a team of investigators at Rutgers University, which has developed a biocompatible polymer system that entraps poorly soluble drugs as it self-assembles into nanoparticles. The polymer, comprising both water-soluble segments and water-insoluble segments, forms compact nanoparticles 40 – 70 nanometers in diameter when added to water. The research team, led by Joachim Kohn, Ph.D., also developed a simple “one-pot” chemical method to create the polymer, an important consideration for future commercial development.

Working with the anticancer drug paclitaxel, the researchers examined the effect that changes in the chemical composition of the polymer had on how much drug the nanoparticles could contain. The researchers found that they could fine-tune drug loading levels with slight changes in the polymer. The tunable nature of this system could give pharmaceutical chemists more flexibility in drug formulation efforts.

The researchers then demonstrated that nanoparticles containing paclitaxel were able to deliver the drug to tumor cells. The nanoparticle-paclitaxel combination was as toxic to cultured tumor cells as was a comparable amount of paclitaxel alone. The investigators also showed that the nanoparticles themselves, minus any drug, were not toxic to the cells.

This work is detailed in a paper titled, “Hydrophobic drug delivery by self-assembling triblock copolymer-derived nanospheres.” An abstract is available through PubMed.
View abstract.