Nanoparticle drug formulations for cancer diagnosis and treatment

Over the past ten years, more than a billion dollars in U.S. government funding has been awarded to the development of nanomaterials for clinical diagnosis and therapy. In this article we will focus on one subset of nanotechnology: nanoparticle formulations of drugs intended to diagnose or treat cancer. Several nanoparticle drug preparations are now in widespread clinical use, and dozens are in the pipeline. In some cases the nanoparticles are simply passive drug carriers or contrast agents; in others, the nanoparticles have active therapeutic properties. Cancer, particularly solid tumors, is one of nanotechnology's key targets. The specific challenges involved in cancer treatment are those addressed by multifunctional materials, in particular, inaccessibility, widespread metastasis, low oxygen concentrations, and resistance to drugs and radiation. Nonetheless, major barriers still remain to effective nanoparticle design and approval.