Tiny gold and iron oxide particles, with antibody guides to steer them through the bloodstream toward colorectal cancer cells, quickly kill cancer cells with absorbed infrared heat, scientists report.
“It’s a simple concept. It’s colloidal chemistry. By themselves, gold and iron-oxide alloys are benign and inert, and the infrared light is low-power heating,” says Carl Batt, professor of food science at Cornell University and the senior author of the paper.
“But put these inert alloys together, attach an antibody to guide it to the right target, zap it with infrared light, and the cancer cells die. The cells only need to be heated up a few degrees to die.”
Batt and his colleagues report their findings in Nanomedicine.
For cancer therapy, current hyperthermic techniques—applying heat to the whole body—heat up cancer cells and healthy tissue alike. Thus, healthy tissue tends to get damaged.
This study shows that using gold nanoparticles, which amplify the low energy heat source efficiently, can better target cancer cells and mitigate heat damage to healthy tissues. By adding the magnetic iron oxide particles to the gold, doctors watching MRI and CT scanners can follow along the trail of this nano-sized crew to its target.
When a near-infrared laser is used, the light penetrates deep into the tissue, heating the nanoparticle to about 120 degrees Fahrenheit—an ample temperature to kill many targeted cancer cells.
This results in a threefold increase in killing cancer cells and a substantial tumor reduction within 30 days, according to first author Dickson K. Kirui, a postdoctoral fellow at Houston Methodist Research Institute.
“It’s not a complete reduction in the tumor, but doctors can employ other aggressive strategies with success. It also reduces the dosage of highly toxic chemicals and radiation—leading to a better quality of life,” he explains.
Ildar Khalidov of Weill Cornell Medical College and Yi Wang of Cornell also contributed to the study, which the Ludwig Institute for Cancer Research and Kirui’s Sloan Foundation Graduate Fellowship partially funded.
Source: Cornell University