In an international study, Type 1 diabetes patients reported the bulkiness of insulin pumps, their interference with activity, embarrassment, injection site pain, and inconvenience to be their top reasons for not adhering to prescribed insulin regimens.

An interdisciplinary team of researchers at Virginia Tech and Georgia Tech is after better solutions for patients with wearable drug delivery devices.

Anne Staples, associate professor in the Department of Mechanical Engineering, is the primary investigator of a Trailblazer Award funded through the National Institutes of Health that will tackle these patient concerns. The award will deliver $550,000 over three years to develop bio-inspired microfluidic pumps with applications in vaccinations, hormone treatment, chemotherapy, and diabetes maintenance. As the leader of the project, Staples aims to make drug delivery less painful and more convenient in collaboration with two colleagues:

  • Leanna House, associate professor in the Department of Statistics, Virginia Tech College of Science
  • Rafael Davalos, Margaret P. and John H. Weitnauer Jr. Chaired Professor, Wallace H. Coulter Department of Biomedical Engineering, Georgia Tech

The team is exploring how to lighten the load of drug delivery technologies by reducing their size and finding new ways to power them. The small size of these instruments and their use of tiny components classifies them by a name that sums up the package: micropumps. The basic operational principle for a micropump is inspired by the mechanisms through which insects transport respiratory gases in their naturally occurring systems.

Specifically, the project will investigate new options for ambulatory infusion pumps, which are portable drug delivery devices allowing a patient to receive liquid IV or transdermal drugs, hormones, vaccines, and biologics, while remaining mobile. 

“The way our research comes together in this project seems obvious, once you see it,” said Staples. "Putting our bioinspired pump technology together with previous research we have conducted will lead to a new platform technology for liquid infusion that could improve the quality of life for people requiring various therapies, and that’s exciting.”

The goal is to create an initial set of six wearable infusion patch pump designs. Staples expects that the result will be a featherweight pulse-driven pump similar to a nicotine patch. There is also the possibility of developing sophisticated, closed-loop or implantable pump systems that have a smaller footprint than current devices.

Lightweight, small-scale pump developed by Anne Staples' team. Photo by Alex Parrish for Virginia Tech.
A lightweight, small-scale pump developed by Anne Staples' team. Photo by Alex Parrish for Virginia Tech.

Meeting a pumped-up demand

The use of portable drug-delivery machines spiked during the COVID-19 pandemic when the convenience of IV treatment without a trip to the doctor’s office was an effective tool for treating chronic illness. By carrying their treatments with them, IV-on-the-go patients have been able to administer their own drugs for cancer, diabetes, post-operative pain management, and more.

Before receiving the Trailblazer Award, the team produced a prototype micropump. It was small and lightweight, powered by the patient’s pulse instead of electricity, and used the micro-sized needles the team previously developed for drug delivery. 

“This work is more than an intellectual exercise advancing scientific theories,” said House, whose statistical modeling expertise equips the team with the ability to simulate, compare, and optimize prototypes. “It also presents opportunities to make the lives of people, such as those with diabetes, easier.” 

Teaming up with specialists

Staples has a decade of research experience in microfluidics. This expertise helps her scale down the physical size of medical devices and develop innovative approaches to drug delivery. Her pursuits have produced publications on arrays of micro-sized needles, new tools for the treatment of diabetes, and wearable drug delivery patches powered by a person’s pulse. With that strong collection of separate tools, her team turned its attention toward bringing the pieces together into a device that might improve the lives of those who rely on drug treatment regularly.

Before putting the device into clinical testing with human subjects, Staples recognized the benefit of experimenting with the device’s functionality through mathematical modeling. Led by House, such modeling creates a virtual environment to simulate treatment and test hypothetical mechanisms, giving a better idea of how the whole device might work for individual patients. Does the pulse provide enough power to consistently deliver the needed drugs? How could that change for someone with a weaker pulse? Are the micro-sized needles suitable for the job? 

“We’re thrilled to collaborate with Dr. House on this project,” Staples said. “Statistical analyses will help the team sort through the noise and quickly identify which design factors and tests to focus on going forward, accelerating our efforts. We’ve also assembled an amazing team of six talented undergraduate researchers from several College of Engineering and College of Science programs at Virginia Tech.”

For a strong background in medical device development, Staples called on Davalos. He has been part of multiple collaborations in the production of microfluidic prototypes and also directs lab facilities that offer state-of-the-art testing in advance of clinical trials. 

Together the team will collect findings from Staples’ past and ongoing research in this area and deliver the data to House. The team will build mathematical representations of those findings and also build the framework for comparison. Some data comparisons will include the following:

  • The rate at which fluids flow through the pump for different heart rates and blood pressures
  • Device design and the way it uses the energy of a person’s pulse
  • How pumping across the skin barrier will affect the pump flow rate, using existing biological models like porcine skin

The Trailblazer Award is given to faculty who have completed their final degree within the last 10 years, defining them as an “early stage investigator,” or to established investigators from the physical sciences who are new to the National Institute of Health. Funds from this award enable a researcher to pursue programs that tackle high risk, high impact research of interest to the National Institute of Biomedical Imaging and Bioengineering.

 

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