In the last decade, noteworthy advancements in medical applications of nanotechnology have become more prevalent. As SingularityHub points out, researchers are developing nanoscale patterns on medical implants that can stimulate bone cell growth and positive gene expression. Others are working to make guided nanoparticles that detect (and even destroy) cancer cells.
Multiple groups, like the Center for Cancer Nanotechnology Excellence at Stanford, are altering various nanoparticles to get behaviors useful to medical professionals. For example, nanoparticles are being created that give off a detectable color signal when a cancer cell is found or that hold onto a cancer cell until it can be studied.
More unique reactions have been developed in the lab. For instance, some nanoparticles absorb light and then produce very low-power acoustic vibrations when a tumor is located or even release heat to kill a cancer cell.
At the University of Chicago, scientists are testing a way to spur checkpoint blockade into more potent action using nanoparticles. Checkpoint blockade therapy works by interfering with cancer’s ability to turn off the body’s immune reaction. When cancer cells first develop, the body is able to recognize them as foreign, triggering T-cells to attack and eliminate them.
As malignant cells multiply and form tumors, they release biochemical signals that suppress the immune system, and the T-cells no longer function properly. Checkpoint blockade therapy obstructs those signals, makes T-cells see the cancer cells as invaders again and allows the immune system to do its job. The problem, says chemistry professor Wenbin Lin, is that if a tumor has been growing for years there are no longer any T-cells inside it to activate. This causes the therapy to fail.
“So, what we’re trying to do is to come up with ways to recruit T-cells to the tumor,” he says, “and if you have a way to make the T-cells recognize cancer cells, the T-cell will be able to kill the cancer cells.”
The treatment Lin and collaborators invented is a drug cocktail contained in nanoparticles. The nanoparticles assemble themselves from zinc and a drug called oxaliplatin, which is widely used against advanced-stage metastatic colon cancer. A photosensitizing agent called pyrolipid forms the outer layer.
When light is shined on the pyrolipid, it generates molecules that can kill cancer. It also activates T-cells that can recognize cancer cells thereby enabling the nanoparticles to pack a triple punch.
Used in concert, the nanoparticles and a checkpoint blockade agent eliminated tumors in a mouse, even when the tumors were widely separated and one tumor had received no treatment. This ability to activate T-cells in one place and have them travel to disease sites in the body could be a powerful tool for treating cancer.
Most patients that struggle in their battle with cancer do so because of metastatic disease, not their primary tumor. When patients have surgery, doctors don’t know if there are other, smaller lesions elsewhere in the body.
“You cannot treat them because you don’t know where to look for them,” Lin says. “If you activate immune cells, they can home in to cancer cells selectively. So, you have a better chance of getting rid of these small metastatic tumors throughout the body.”
Although ongoing research is still needed to ensure the safety and success of nanotechnology medical applications, recent discoveries definitely make you think about what is to come. Treatments, such as those for cancer, could look very different in the near future.
(Photo: Nanotechnology Book Cover by jurvetson)