(Nanowerk News) Many of the most potent anticancer agents are poorly soluble in water, presenting a challenge for medicinal chemists who must develop methods of delivering these drugs in the watery environment of the human body. Nanoparticles appear to be perfectly suited to this task, and indeed, numerous research groups are developing nanoparticles specifically for delivering water-insoluble drugs to tumors.
The investigators created these nanoparticles from two different polymers that crosslink to each other when exposed to light from an argon laser for one hour. They then added the nanoparticles to a solution of doxorubicin and evaporated the solvent used to dissolve the anticancer drug. Nearly half of the drug in solution became encapsulated within the nanoparticles. The researchers note that the resulting nanoparticles contain a protein-repelling surface coating that should result in favorable pharmacokinetic behavior.
Experiments to test the drug-release characteristics of these nanoparticles showed that maximum release occurred at approximately eight hours and then remained close to that level for a week. The data imply that release occurs through a diffusion mechanism, that is, drug travels through channels in the nanoparticle to the nanoparticle surface, as opposed to a disintegration mechanism in which the nanoparticle falls apart and releases drug.