Microneedles are only two to three times the diameter of a human hair and approximately 1 millimeter long. But the impact is significant, from enabling U.S. military personnel in the field to diagnose infectious diseases early to helping individuals monitor their health.
Sandia National Laboratories is at the forefront of microneedling research and is partnering with other companies to expand the technology.
Microneedling is a minimally invasive method for sampling interstitial fluid from beneath the skin. Although interstitial fluid has many similarities to blood, there is still much to learn about it.
Adam Bolotsky demonstrates how Sandia National Laboratories collaborated with SRI to enhance interstitial fluid extraction. Improved extraction methods yield more liquid in less time. (Photo: Craig Fritz) Click on the thumbnail to see a high-resolution image.
“When we started research in this field in 2011, our goal was to develop microneedles as a wearable sensor that could replace blood samples,” says Sandia, who has led the microneedle research. Ronen Polsky said. Microneedles can access interstitial fluid for real-time and continuous measurement of circulating biomarkers.
“People wear continuous blood glucose monitors to measure their blood sugar levels,” Polsky says. “We want to extend this to all other conditions to take advantage of this minimally invasive sampling using microneedles.”
Sandia's collaboration with external partners has resulted in increased speed of interstitial fluid extraction. This could bring microneedle sensors to market sooner for other applications such as virus detection and electrolyte levels. Sandia recently received a patent for a microneedle sensor that Polsky and his team are aiming to commercialize.
“We're basically going to give patients a diagnostic lab in the form of a wearable device,” he said.
Sandia currently partners with SRI, Adaptyx Biosciences, and the University of California, Berkeley.
Faster extraction
One project with SRI, an independent nonprofit research organization, has significantly improved interstitial fluid extraction.
“Previous methods were very variable,” Polsky said. “It took him an hour or two to collect enough fluid for analysis.”
As seen in the extraction device here, the microneedles are approximately 1 millimeter long. Researchers at Sandia National Laboratories say comfort is important when designing microneedles to extract interstitial fluid. (Photo: Craig Fritz) Click on the thumbnail to see a high-resolution image.
The technique involved using an array of four or five needles with five needles each.
“Through a new project with SRI, we have refined a technology that allows us to use a single microneedle to collect enough fluid for testing in about 10 minutes,” Polsky said. “The new technology works faster and allows you to get more fluid.”
Although the microneedles penetrate the outer layer of the skin, they do not reach the nerve endings and are hollow. Engineers at Sandia's Advanced Materials Laboratory made several changes to improve the extraction technique, including changing the shape of the 3D-printed needle holder.
“There are engineering and comfort concerns with microneedles that are impacting how they are designed,” Sandia engineer Adam Bolotsky said. “We received feedback from our participants as we updated the design, and we believe we have found the optimal depth to collect maximum fluid while minimizing discomfort.”
Is it viral or bacterial?
Will Brubaker is the principal investigator on SRI's microneedling project. He said improvements in interstitial fluid extraction could lead to expanded use of microneedles.
“If we can collect more samples in a shorter period of time, we can recruit more people to this type of study,” Brubaker said. “Improving collection methods opens many doors to other uses.”
One such application involves using microneedles to differentiate between bacterial and viral infections. This is another project in which Sandia and SRI are collaborating.
“Being able to distinguish between bacterial and viral infections allows doctors to make informed decisions faster and get treatment as early as possible,” Polsky said. Ta.
The Defense Threat Reduction Agency is funding the project.
“This could be diagnostic for service members who are feeling sick and exhibiting symptoms,” Brubaker said, adding that the test can perform continuous health monitoring using interstitial fluid. He added that this is a step toward developing a device. He said there is still much work to do before seeking FDA approval.
“It's very clear that this test could eventually be used by the general public,” Brubaker said.
Current work with SRI is scheduled to conclude in October.
Adaptix Bioscience
Sandia is also collaborating with Adaptyx Biosciences under a joint research and development agreement. Adaptyx wants to better understand what biomarkers are present in interstitial fluid.
“We want to broadly understand the components of interstitial fluid and how those components correlate with blood measurements,” said Alex Yoshikawa, co-founder of Adaptyx. “We are leveraging Sandia's existing technology for basic physiological research.”
Brittany Humphrey prepares microneedles in a fume hood at Sandia National Laboratories. (Photo: Craig Fritz) Click on the thumbnail to see a high-resolution image.
As part of this collaboration, Sandia is using an improved method developed with SRI to extract interstitial fluid from volunteers in the field.
“It's much easier to recruit volunteers because they only have to spend 15 minutes of their time compared to having to spend two hours,” says Brittany, who coordinates and oversees Sandia's extraction efforts.・Mr. Humphrey says. “Extraction essentially requires little to no work on their part.”
Yoshikawa said Adaptix is analyzing collected body fluids with the aim of developing continuous monitoring devices for the general public.
electrolyte sensor
Sandia is also partnering with the University of California, Berkeley, to develop microneedle electrolyte sensors.
“In this case, we are functionalizing the microneedles to be sensitive to electrolytes such as sodium, potassium, and calcium,” Polsky said.
Work has just begun on the second year of a three-year project. Similar to wearable blood glucose meters, continuous electrolyte monitoring may help manage cardiovascular function, hydration levels, and electrolyte imbalances in a variety of conditions.
“Studying interstitial fluid is not easy,” says Polsky. “Sandia has a strong track record in this field, and we are known as a world leader in this effort. This effort has been a cross-functional collaboration with many others.”
Sandia National Laboratories is a multi-mission laboratory operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration. With principal facilities in Albuquerque, New Mexico and Livermore, California, Sandia Laboratories has primary research and development responsibilities in nuclear deterrence, global security, defense, energy technology and economic competitiveness.
/Open to the public. This material from the original organization/author may be of a contemporary nature and has been edited for clarity, style, and length. Mirage.News does not take any institutional position or stance, and all views, positions, and conclusions expressed herein are solely those of the authors. Read the full text here.
