Adam de la Zerda, PhD, lights up tumors with lasers, sound, and nanoparticles

“The first question most graduate students are asked when they want to join a lab is ‘Are you funded?’ That’s the wrong question. It should be ‘What really excites you?’”
- Adam de la Zerda, PhD

One million cancer cells. Once a tumor grows beyond this size (about a millimeter), it gets aggressive. It starts attracting blood vessels, growing faster, and spreading to other parts of the body. Unfortunately, MRIs and CT scans are limited to a resolution of several millimeters, or about 10 million cells, which means clinicians can only “see” tumors that have grown past this critical threshold.

But not for long. Adam de la Zerda and his team have figured out a way to detect tumors a tenth that size. Called photoacoustic molecular imaging, it works like this: first, gold nanoparticles are coated with antibodies keyed to bind to specific molecules (called biomarkers) produced by a patient’s tumor. Then these coated nanoparticles are injected into the bloodstream. As they encounter cells displaying the biomarkers, these tiny antibody-covered nuggets glom on, sticking to tumor cells like magnets while passing normal cells by.

Next, the area is illuminated with laser pulses while an ultrasound is conducted. The laser light is absorbed by the gold cores of the nanoparticles, causing them to heat up and expand. This pushes on the tissues around the tumor, and the resulting tiny shock waves produce ultrasound signals from which a 3-D image of the tumor can be computed. It’s a quantum leap forward. With the precision guidance of antibodies and 10 times the resolution of the current standard, Adam’s method promises to revolutionize oncology.

When he first came to Stanford, Adam wanted to pursue a PhD in electrical engineering. But soon after he arrived, a close friend died of cancer. Deeply affected, he decided to devote his skills to helping patients. Encouraged by advisors, he shadowed Stanford physicians for inspiration. It struck as he watched a breast cancer surgery: he would build more accurate imaging tools.

Thanks to a Bio-X fellowship funded by philanthropy, Adam had the freedom to drastically alter his focus and join the lab of Sam Gambhir, MD, PhD, chair of radiology and director of Stanford’s molecular imaging program. With Sam as his mentor and guide, he took off in a bold new direction that ultimately led him to develop photoacoustic molecular imaging.

That initial investment in Adam paid off immensely. Now he has his own lab and is collaborating with industry and Silicon Valley to make this technology widely available. He’s also pursuing new ideas. “From 10 million cells to one million,” he muses. “Not bad. But I want to get it down to just one cell.”