Tiny Rockets Race Through Blood Samples

Summary and Introduction

by the blog author

Gold and platinum microtubes use oxygen from hydrogen peroxide to zoom around in a blood sample. A special coating on the outer surface catches cancer cells rather than normal cells. The microtubes are then retrieved and the attached cells analyzed. It’s quicker and more definitive than separating the cancerous cells from the rest of the blood through chemical and biological processes.

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Tiny Rockets Zoom Into Blood
to Capture Cancer Cells

By Charles Q. Choi, InnovationNewsDaily Contributor
April 29, 2011

Blasting through blood samples like a missile roaring through the sky, a new breed of microscopic rocket searches out cancer, propelled by chemical boosters. Designed by scientists to speed up the identification of chemicals, these tiny rockets take the power of the space age down to the nanoscale.

The micro-rockets consist of tapered metal tubes 60 microns long, or about two-thirds the width of a human hair. Their interiors are lined with platinum, a metal that breaks down hydrogen peroxide, a common ingredient of bleach. This generates oxygen bubbles that naturally rush out each tube's wider end – jet propulsion for speeds of roughly 85 microns per second.

"This is the first time we showed we can propel micro-rockets in biological media like blood," said Joseph Wang, a nanoengineer at the University of California, San Diego, "In the future, we can think of putting other receptor molecules on these micro-rockets to capture other targets of interest."

An iron layer sandwiched between the platinum interior and gold exteriors of the roughly 5-micron-wide tubes lets the researchers steer the rockets using magnetic fields.

The outer surfaces of these microtubes are platforms onto which the scientists can chemically attach antibodies, the molecules our immune system employs to latch onto and tag invaders. The researchers use these antibodies to bind the microtubes onto specific targets, such as a protein known as carcinoembryonic antigen, which is found in overly large amounts in approximately 95 percent of colorectal, gastric and pancreatic cancers.

In tests with human blood serum where scientists added hydrogen peroxide, pancreatic cancer cells and noncancerous immature white blood cells, the micro-rockets latched onto their cancerous targets 70 percent of the time, zipping around even while carrying their prizes with only a slight drop in speed. The microtubes did not bind the same way to noncancerous cells when rubbed against them.

These micro-rockets could serve as a novel way to capture relatively rare circulating tumor cells for cancer diagnosis tests without the substantial preparation of blood samples needed for other techniques that exist for isolating and counting these cells.

This article was provided by InnovationNewsDaily, a sister site of TechNewsDaily.

http://www.technewsdaily.com/cancer-finding-blood-rockets-2589/


[this link has some nice graphics and microscopic photographs of he rockets in action]