Researchers at the University of California in Irving have managed to discover a way to greatly improve the way chemotherapy is used to target specific organs and even specific cells.

The researchers used liposomes, which are small spheres less than 100 nanometers in diameter, of naturally occurring lipid molecules as packages for the chemotherapeutic agent doxorubicin and additionally a small peptide molecule to “address” the delivery of said package to the tissue being targeted.

Using this technology the team, led by Kenneth Longmuir, associate professor of physiology & biophysics, and Richard Robertson, professor of anatomy & neurobiology at UCI, were able to show that the doxorubicin was almost completely directed to the intended target region, with very little uptake by other organs such as the lung, heart and kidneys.

The researchers based their new approach upon the fact that all tissues and organs in the human body, including cancer tumors, are naturally surrounded by s dense region of sugar-containing molecules called polysaccharides, the chemical composition of which differs in various regions of the body. This chemical makeup is also very different in tumor cells than it is in healthy ones.

The team developed a nanocarrier system that can distinguish between the different types of polysaccharides and were able to demonstrate that via this method the nanocarriers and their chemotherapeutic contents could be accurately delivered to specified organs and other targets.

Their results are especially important because although doxorubin is an efficient drug against cancer tumors its use has previously been accompanied by the serious side effect of damage to healthy surrounding tissues. When it is administered in a more traditional manner it has been shown to distribute widely through the system, damaging organs that are distant from the tumor location.

This potential for damage, especially for serious heart damage, has in the past limited the number of doxorubin treatments that doctors administer to their patients. In their work Longmuir, Robertson and their colleagues were able to demonstrate by using the nanocarrier pacakages the drug could be effectively delivered to say the liver without it reaching the heart with an accuracy level of better than 100:1. The clinical result of this is that in the future patients who need it could receive more doxorubin treatments than previously thought advisable.

The research team will now continue their work, which is supported by the National Institute of Biomedical Imaging and Bioengineering (NIBIB) of the National Institutes of Health, by using their drug delivery system in various different cancer models.