Research Foundation News

September 16, 2021

Purdue microneedles pierce biofilm for more effective topical delivery of antibiotics to infected wounds

WEST LAFAYETTE, Ind. – A Purdue University engineer's patent-pending invention could improve the quality of life for millions of people suffering from diabetic foot ulcers.

Rahim Rahimi, an assistant professor in the School of Materials Engineering, has developed a flexible polymer composite microneedle array that can overcome the physicochemical bacterial biofilm present in chronic, nonhealing wounds and deliver both oxygen and bactericidal agents simultaneously. The results have been published in ACS Applied Bio Materials. A video about the invention is available on the Purdue Engineering YouTube channel.

"The biofilm acts as a shield, hindering antibiotics from reaching infected cells and tissues," Rahimi said. "When these microneedles pierce through the shield, they absorb the fluid underneath and dissolve, which delivers the antibiotic directly to the ulcerated cells and tissues."

rahimi-rahim Rahim Rahimi, assistant professor of Materials Engineering, College of Engineering, Purdue University (Purdue University photo/Vincent Walter) Download image

Rahimi said the traditional method to bypass biofilm is for physicians to peel it off, which is painful to patients and doesn't discriminate unhealthy tissue from healthy tissue.

"The microneedles don't cause pain because they are not long enough to touch nerve endings in the foot," he said. "In this published study, the team assessed the microneedles on ex vivo porcine wound models. In fewer than five minutes, the microneedles dissolved, the antibiotic was delivered and the patch was removed."

The lack of proper treatment of infected ulcers can lead to bacteremia and sepsis. As a result, chronic wounds are one of the key causes of limb amputations.

The next step to developing the microneedles beyond the proof-of-concept stage is to find partners to conduct human tests. Rahimi has disclosed the innovation to the Purdue Research Foundation Office of Technology Commercialization. OTC has filed a patent application on the intellectual property. The innovation is available for licensing.

About Purdue Research Foundation Office of Technology Commercialization

The Purdue Research Foundation Office of Technology Commercialization operates one of the most comprehensive technology transfer programs among leading research universities in the U.S. Services provided by this office support the economic development initiatives of Purdue University and benefit the university's academic activities through commercializing, licensing and protecting Purdue intellectual property. The office recently moved into the Convergence Center for Innovation and Collaboration in Discovery Park District, adjacent to the Purdue campus. In fiscal year 2020, the office reported 148 deals finalized with 225 technologies signed, 408 disclosures received and 180 issued U.S. patents. The office is managed by the Purdue Research Foundation, which received the 2019 Innovation and Economic Prosperity Universities Award for Place from the Association of Public and Land-grant Universities. In 2020, IPWatchdog Institute ranked Purdue third nationally in startup creation and in the top 20 for patents. The Purdue Research Foundation is a private, nonprofit foundation created to advance the mission of Purdue University. Contact for more information.

About Purdue University

Purdue University is a top public research institution developing practical solutions to today’s toughest challenges. Ranked in each of the last four years as one of the 10 Most Innovative universities in the United States by U.S. News & World Report, Purdue delivers world-changing research and out-of-this-world discovery. Committed to hands-on and online, real-world learning, Purdue offers a transformative education to all. Committed to affordability and accessibility, Purdue has frozen tuition and most fees at 2012-13 levels, enabling more students than ever to graduate debt-free. See how Purdue never stops in the persistent pursuit of the next giant leap at

Writer: Steve Martin,

Source: Rahim Rahimi,

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