How a nanotechnology advance could make drug development faster

Researchers at Stanford University are using nanosensors to transform a centimeter-sized microchip into a stand-in for the human body in the drug development process. A tiny, protein-packed chip could let drug developers measure a medication's affinity for every human protein with just one test.

I spoke last week with Richard Gaster, a PhD candidate in bioengineering and medicine and first author of the paper in Nature Nanotechnology. Below are excerpts from our interview.

How could a centimeter-sized microchip with nanosensors impact the drug development process?

The advantage to using a nanosensor is we can pack many, many sensors into one small array. It's just as costly for us to have one sensor in a centimeter square as it is to have a thousand. By using nanotechnology to make these high-density sensor arrays, we are able to screen for many different interactions simultaneously. You have a unique protein on each sensor. Sensor 1 will have liver protein. Sensor 2 will have kidney protein. Sensor 3 will have brain protein and so on. We can add the drug to the sensor array to see how strong the drug binds to these different proteins. Instead of looking for interactions to each of these in separate experiments, we can look at everything [in one experiment].

Take me through the process of using this microchip during drug development.

The goal is to test once a drug is developed. If you're developing a breast cancer drug, you want to see how strongly it binds to the breast cancer target. You keep modifying it to make it stronger. But before you put it in a human, you want to know how strongly it binds to other targets as well. We're not developing the drugs. Our goal is to test them before you put them in a human.

The sensors we're using are actually used in your computer hard drive. We're using the same sensor technology to detect proteins that are labeled with a magnetic bead. As a protein comes closer to our sensor, the magnetic bead that is bound to it comes closer and can detect the presence of the protein. We'll label the drug with the magnetic bead. By employing this magnetic label, we can get much more sensitive detection and much quicker results. Part of the innovation is that people haven't used these labels for kinetic information. We have to write a new mathematical model to understand what we're seeing. We then compared the existing standard technology to ours. We got equally quantifiable data, but we can do it on a more massive scale and much quicker.

Can you explain in greater detail how this advances the current standard?

Adding a tag -- this magnetic label -- to the protein changes the binding interaction. We have to be able to understand how it changes the binding interaction to calculate the affinity without the label. By writing a new model to account for this effect, we can remove the effect in the end.

What's the next step for this work?

The next step is to put this into real practice. Doing experiments in the laboratory setting is the first step to the proof of principle. The ultimate goal is to scale it up [and] be able to test every protein in the human body. [We want] to start putting different drugs on it to see how these drugs interact with all the proteins. When these drugs are put in human patients, we want to see whether our technology is capable of predicting adverse effects.

Image: An array of 64 nanosensors appear as small dark dots in an 8 x 8 grid in the center of an illuminated part of a backlit microchip / By Sebastian Osterfeld

Photo: Richard Gaster / By Stefanie Monica

This post was originally published on Smartplanet.com