Asan Medical Center Develops “Surface-Fluidic Microneedle Patch” Capable of Delivering Drugs to Lymph Nodes

In Animal Models, Drug Reaches Target Within 10 Minutes of Patch Application — Comparable to Injection

“We Aim to Enable Not Only Delivery of Contrast Agents and Anticancer Drugs, but Also Diagnosis and Monitoring of Lymphatic Disorders”

▲(From left) Professor Jae Yong Jeon of the Department of Rehabilitation Medicine at Asan Medical Center, University of Ulsan College of Medicine, Researcher Hwayeong Cheon of the Biomedical Engineering Research Center, and Professor Hyunsik Yoon of Seoul National University of Science & Technology

As various noninvasive drug delivery technologies are being developed to ease the discomfort of patients who undergo repeated injections, a Korean research team has recently developed a technology that enables the administration of large doses of drugs using a single patch—without any injections.

A joint research team led by Professor Jae Yong Jeon of the Department of Rehabilitation Medicine at Asan Medical Center, University of Ulsan College of Medicine, Researcher Hwayeong Cheon of the Biomedical Engineering Research Center, and Professor Hyunsik Yoon of Seoul National University of Science & Technology has recently developed a Surface Fluidic Microneedle Patch (SFMNP) capable of rapidly delivering large doses of drugs without injections.

When the patch was applied to a small-animal model, the contrast agent reached the lymph nodes within 10 minutes, and the drug was successfully delivered at a level comparable to that achieved with conventional syringe injections.

The findings of this study were recently published in ‘Advanced Functional Materials’ (impact factor 19.0), a leading international journal in the field of functional and nanomaterials. The research was also featured as a ‘Back Cover Article’ and selected as a ‘Hot Topic’ by ‘Chemistry Europe’, drawing significant international attention.

Fluids in the human body flow from blood vessels through the interstitial space and lymphatic vessels to the lymph nodes, eventually returning to the veins. The interstitial space, which connects the lymphatic vessels to the lymph nodes, has recently emerged as a key target for site-specific drug delivery.

While syringes are commonly used to administer necessary medications, microneedles that can deliver drugs or contrast agents without pain are gaining increasing attention as a more convenient alternative for patients with chronic diseases or those requiring repeated monitoring.

However, conventional microneedle technologies often face limitations such as low drug-loading capacity or inadequate penetration of the drug beyond the skin surface into the interstitial space. Attempts to overcome these drawbacks have typically resulted in more complex manufacturing processes or higher production costs.

The research team developed a SFMNP that utilizes capillary action to allow high doses of drugs to spontaneously diffuse into the interstitial space beneath the skin. Capillary action refers to the ability of a liquid to move through narrow spaces without the need for external pressure.

To harness capillary action, the research team designed the microneedle patch with a continuous, hierarchical structure that connects channels of varying sizes from a large drug reservoir to 1 mm-sized holes and finally to microscopic microneedles.

In other words, the SFMNP includes a large reservoir capable of storing drugs or contrast agents. The drug moves from the reservoir through 1 mm-sized holes into the patch, and then spreads along the microchannels formed between the patch surface and the skin through capillary action, naturally reaching the microneedles.

The research team first evaluated the efficacy of the microneedle patch through basic experiments, including mechanical insertion tests and in vitro studies. The results confirmed that the drug was drawn in by capillary action and successfully reached the lymphatic capillaries through the 0.2–0.3 mm microchannels created by the microneedles, without any drug loss during delivery.

Furthermore, when the SFMNP was applied to an animal (in vivo) model to administer a contrast agent for lymphography, the researchers confirmed that the agent reached both the interstitial space and the lymph nodes within 10 minutes.

The SFMNP can be mass-produced through a simple manufacturing process. As a disposable patch, it reduces the risk of infection and significantly enhances patient convenience.

Professor Jae Yong Jeon of the Department of Rehabilitation Medicine at Asan Medical Center stated, “The SFMNP we developed offers both superior efficiency and greater patient convenience compared to conventional injections in delivering drugs targeting the interstitial and lymphatic systems, such as contrast agents and anticancer drugs. Moving forward, we aim to advance this technology into a next-generation drug delivery platform that can be expanded to the diagnosis of diseases such as lymphedema and lymph node metastasis, as well as the monitoring of treatment responses.”

Professor Hyunsik Yoon of the Department of Chemical & Biomolecular Engineering at Seoul National University of Science & Technology stated, “Because the surface-fluidic microneedles can be produced through a continuous mass-production process, this technology is expected to significantly accelerate commercialization.”