Study points way to precisely targeted cancer treatments
UC Irvine researchers have created a new approach that vastly improves the targeting of chemotherapeutic drugs to specific cells and organs.
Kenneth Longmuir, associate professor of physiology & biophysics, and Richard Robertson, professor of anatomy & neurobiology, used liposomes, small spheres (less-than 100 nanometer in diameter) of naturally-occurring lipid molecules, as "packages" for the cancer chemotherapeutic agent doxorubicin, and a small peptide molecule to "address" the package to the targeted tissue.
Using this technology, the research team demonstrated that the doxorubicin was directed almost entirely to the targeted site with virtually no uptake by other organs, including lung, kidney and heart.
Their study appears online in the International Journal of Pharmaceutics.
Their approach is based on the fact that all tissues and organs, including all tumors, are surrounded by a dense region of sugar-containing molecules called polysaccharides. Most importantly, the particular chemical composition of the polysaccharides is different in each tissue and organ of the body. The chemical compositions of the polysaccharides of tumor regions are also different from normal tissue.
The research team developed a nanocarrier system that can recognize specific types of polysaccharide, and has demonstrated effective, organ-specific delivery of nanocarriers, and their therapeutic contents, based upon this polysaccharide-targeting approach.
In their study, the researchers used a peptide derived from a protein found in the microorganism Plasmodium, which is an organism well-known for its exceptional ability to exclusively target the polysaccharides of liver following entry into the bloodstream.