Removing Nanoparticles from your Blood
Nanoparticles — tiny objects 1,000 times smaller than the width of a human hair — are gaining popularity as vehicles for delivering drugs to targeted sites in the body. However, removing these nanoparticles from the bloodstream for further study is a time-con-suming and challenging task. Nanoengineers at the Jacobs School have developed an electric chip that separates drug-delivery nanoparticles from blood within minutes.
The new technology will enable research-ers to study what happens to drug-delivery nanoparticles circulating in a patient’s blood-stream and determine whether these parti-cles are compatible with a patient’s blood.
“We were interested in a fast and easy way to take these nanoparticles out of blood plasma so we could find out what’s going on at their surfaces and redesign them to work more effectively in blood,” said Michael Heller, a nanoengineering professor at UC San Diego and senior researcher on the project.
The electric chip used to isolate drug-de-livery nanoparticles was manufactured by Biological Dynamics, a Jacobs School spin-
Nanoparticle removal from blood
out which licensed the original technology from Heller’s lab. The chip is the size of a dime and contains hundreds of tiny electrodes that generate a rapidly oscillating electric field that selectively pulls nanoparticles out of a plasma sample. After inserting a drop of blood plas-ma spiked with nanoparticles into the electric chip, researchers demonstrated nanoparticle recovery within seven minutes.
The technology works on different types of drug-delivery nanoparticles. Moreover, the technique doesn’t require any modifications to the nanoparticles or plasma samples — an advantage over other nanoparticle separation methods.
The chip’s ability to pull nanoparticles out of plasma is based on differences in material properties between the nanoparticles and plasma components. When the chip’s elec-trodes apply an oscillating electric field, the nanoparticles’ positive and negative charges re-orient at a speed different from the charges in the surrounding plasma. This mo-mentary charge imbalance creates an attrac-tive force between the nanoparticles and the electrodes. As the electric field oscillates, the nanoparticles gravitate toward the electrodes while plasma stays behind. The electric field is designed to oscillate at just the right frequen-cy to do this: 15,000 times per second.