One of the hallmarks of many nanoparticle-based anticancer therapeutics and imaging agents is that they accumulate in tumors thanks to the fact that they are small enough to escape from the bloodstream through the leaky blood vessels that surround tumors.
And although many if not most tumors are surrounded by leaky blood vessels, the extent of that leakiness varies widely among tumors. As a result, the effectiveness of a given nanoparticle-based therapeutic also might vary from patient to patient in a way that is now impossible to predict.
A research team headed by Ravi Bellamkonda, Ph.D., the Georgia Institute of Technology, appears to have hit on a solution to the problem of determining how much of a nanoparticle drug is actually making it into breast tumors. The team's approach, which is described in a paper in the journal Biomaterials, involves adding an approved x-ray contrast agent to a drug-loaded nanoparticle and then using standard mammography to quantify how much of the nanoparticle accumulates in a particular breast tumor. These results hold promise for personalizing breast cancer therapy.
To create their nanoparticle, the investigators first prepared a highly concentrated solution of the x-ray contrast agent iodixanol and then added two different lipids, one of which was linked to PEG. The resulting lipd-based nanoparticles then were mixed with the anticancer agent doxorubicin for 1 day, yielding a nanoparticle loaded with both anticancer agent and contrast agent.