UIC professor developing finger-prick blood test for toxic metals
Annamarie Garza’s kids like to play soccer at the park near their Southeast Side home. But on especially windy days, she fears there could be a higher risk for exposure to brain-damaging manganese dust from nearby industrial facilities.
“Those are days when we just don’t go outside,” said Garza, a longtime resident of the area who has four children.
Like most of her neighbors – if not all of them – Garza has no idea exactly how much of the neurotoxin she or her family are being exposed to, as current testing methods are costly and generally inaccessible.
University of Illinois Chicago bioengineering professor Ian Papautsky wants to change that. He’s spearheading an effort to develop a portable, smartphone-sized sensor that measures human exposure to lead, manganese and possibly other toxic metals using a single finger prick of blood – and that delivers results in minutes.
The project began about eight years ago, when Papautsky was still at the University of Cincinnati, and will continue thanks to a three-year, $1.8 million grant finalized Aug. 31 by the National Institutes of Health. Since the project’s start, the federal government has spent nearly $3.5 million to fund Papautsky’s research.
If development of the sensor is successful, experts say it will provide public health officials and patients with a faster, cheaper method to detect neurotoxins that can cause learning disabilities, behavioral problems and Parkinson’s disease-like symptoms including tremors and difficulty moving.
Such health risks are of serious concern for Garza and hundreds of thousands of people in and around Chicago, which has more lead service lines for water than any other city in the U.S., and where residents continue to fight industrial sources of pollution.
The latest battle for Garza and other Southeast Side residents involves manganese, a heavy metal used in the steelmaking process that has been linked to declines in IQ, mental processing speed and working memory in children with high exposures.
“[The sensor] could be a real game-changer as far as figuring out where exposures are occurring and doing things to prevent these exposures in the first place,” said Nicholas Newman, director of the University of Cincinnati’s Pediatric Environmental Health and Lead Clinic. “Just to be able to test for things that we think are there and find out whether they are or not, that’s just huge.”
Currently, conducting blood tests for exposure to metals such as manganese is both expensive and time-consuming, costing up to $60 per sample with a wait time of up to six to nine months before a set of samples can be processed and results confirmed. That’s in large part because researchers often have to wait until they collect a larger batch of samples to send them in for testing in order to keep costs down.
Existing methods also require collecting a standard blood draw of about 7.5 milliliters, including when testing kids.
“[Drawing] a tube of blood from a child is not practical,” said Papautsky, the Richard and Loan Hill Professor of Bioengineering in UIC’s College of Engineering. “Just thinking about how my kids react to flu shots – they always try to be brave until they see the needle, and then brave goes out the window. And it doesn’t matter how many princess [bandages] you put on afterward.”
Papautsky’s sensor currently requires a 1-milliliter blood sample to test for metals, but his goal is to be able to conduct testing using a single drop of blood, like a glucometer, which is used by diabetics to monitor blood sugar levels.
During preliminary testing, the sensor has detected levels of manganese with an accuracy of about 90 percent and in just a few hours, though Papautsky hopes to get the wait time down to 10 to 20 minutes.
Papautsky estimates the sensors could cost $10 or less each, not including the hardware or software, which would need to be purchased just once. He said the technology could be ready to hit the market in about five years if it attracts sufficient investment.
“We want to make this process as simple as possible so that it can be done in the field and with low enough limits of detection,” he said.
The last point is key when it comes to lead, Papautsky said, because existing technology for measuring lead levels was developed in the 1980s, when higher levels of exposure were deemed acceptable.
Today, no amount of exposure to lead is considered safe, especially in children – yet the system used to test for lead is unable to detect levels below a certain threshold, Papautsky said. That makes it difficult if not impossible to accurately measure exposure levels in those who live near pollution-emitting factories or other types of industry, he said.
“There have been a lot of concerns from the [National Institutes of Health] that the system is not quite capable of doing these measurements,” Papautsky said.
Papautsky and his colleagues are developing a number of parts needed for the sensors: the chip on which a blood sample is placed; the device that sends an electric current through the chip to separate out the metal contained in the blood; the software to process the results; and the user interface that displays them.
The technology applies the processes of electrochemistry on a micro scale, a first for tests involving blood, Papautsky said.
“We’ll learn so much from this device,” said Erin Haynes, an associate professor in the University of Cincinnati’s Department of Environmental Health. Haynes is a co-investigator on the sensor project, along with University of Cincinnati chemistry professor William Heineman.
Haynes approached Papautsky about developing the metals sensor years ago after becoming frustrated with long wait times to obtain results for a study she was conducting of children in a southeastern Ohio community with high exposures to manganese.
Months after collecting blood samples, Haynes would receive calls from parents wanting to know the results from their children’s tests.
“It could take three to six months, and that was not satisfactory to the participants; they wanted their data,” said Haynes, who said Papautsky’s sensor could “revolutionize” public health efforts to test and treat those exposed to toxic metals.
Next year, Papautsky and his team will seek to validate their sensor by comparing results of blood tests from 150 children in Chicago neighborhoods with heightened exposures to manganese dust. Researchers will test the samples using both existing methods and the new sensor.
Garza said she plans for her children to participate in the study.
“Without having those results, there’s no way we’re going to stop this,” she said. “We have to have proof that people are getting contaminated and it’s making people sick. Without that information, our fight is really difficult.”