Researchers Make Strides in Developing Safe Nano Cancer Detector

Bright red-orange photoluminescence observed from porous silicon nanoparticles with human HeLa cells, magnified 1000x and viewed in the reflection from a silicon wafer. Image courtesy of Luo Gu, Ji-Ho Park, UCSD

The US National Science Foundation has announced that the first biodegradable fluorescent nanoparticle to safely image tumors and organs in live mice has been developed. The nanoparticle potentially could be used for cancer detection and treatment in humans. Developed by researchers at the University of California, San Diego (UCSD), nanoscale “quantum dot” particle can glow brightly enough to allow physicians to examine internal organs. “There are a lot of nanomaterials that have an ability to do fluorescence imaging,” explains chemistry professor Michael Sailor who was instrumental in the research. “But they’re generally toxic and not appropriate for putting into people.” Quantum dots, for instance, can release potentially harmful heavy metals when they break down.

The UCSD researchers designed the new nanoparticle made from silicon wafers, taking thin wafers and running electric current through to construct billions of pores. They then used ultrasound waves to break the wafer into bits as small as 100 nanometers. The resulting silicon particles contained nano-scale features capable of displaying quantum confinement effects, or the so-called “quantum dots.” The ones in the UCSD experiment glowed a reddish color when exposed to red, blue, or ultraviolet light. The new nanoparticle also has the benefit of lasting  long enough before it degrades to release cancer treatment drugs. Ultimately, the material could be used to reduce drug toxicity and treatment costs while improving drug delivery and diagnosis. The researchers believe the material to be safe to use in humans but plan on studying it further to confirm its nontoxicity. “Very high doses of any substance can be harmful,” says Sailor. “The important conclusion from this work is that the materials are nontoxic at the concentrations we need to use to see tumors.”

Tags: nanotechnology