Ten years from now targeted therapies that selectively deliver cell-killing mechanisms to cancer cells will be the dominant method of treating cancer. This sort of technology offers the prospect of removing cancer cells even after metastasis, and with few side effects:
Nanomedicine started creating its own footprint in the sands of cancer research back in the mid-1970s when a group of European researchers discovered what would eventually become known as the liposome. These nano-sized, spherical structures form spontaneously when naturally occurring or synthetic lipids are exposed to water. Although they were identified by accident, these same researchers soon realized the potential of liposomes to carry drugs to diseased cells and tissues.
Around the same time, Massachusetts Institute of Technology research engineer Robert Langer also developed nanoparticles as chains of hydrocarbons known as polymers. Decades later, researchers have shown that such targeted nanoparticle therapies can effectively deliver drug cargo to tumors, while sparing the rest of the body's cells from the drug's toxic effects. Indeed, both types of nanoparticles are in clinical development as cancer-drug delivery vehicles, and some liposome-based have even made it to the market. There are now a total of three nanoparticles on the market as cancer therapies, and at least a dozen more are currently making their way through clinical trials.
The liposome platform is limited, however, in that it cannot release the drug into the tumor in a regulated way. The mechanism of drug release from liposomes is not well-understood, and may involve complex processes such as disruption of the liposome membrane or fusion with cellular membranes. In contrast, the polymer-based nanoparticles [allow] researchers to design treatments that release the chosen drug at a predictable rate controlled by diffusion. "While the first generation of drugs using [lipid] nanotechnology were considered pioneering at the time and became successful blockbuster cancer drugs, they were essentially reformulations of older drugs. Now, the next generation [using polymers] is taking nanotechnology to a whole new level with the ability to fundamentally change the efficacy and safety of drugs. The properties of these advanced compounds are well suited to target rapidly proliferating cells such as cancer cells, and several are already in the clinic."