Historically, conventional needle injections have been the standard for delivering a wide range of therapeutics, but their invasive nature often results in patient discomfort, pain, and poor compliance, especially during long-term treatments. Microneedles, typically micron-scale needles capable of penetrating the skin’s surface without reaching pain receptors, have emerged as a promising alternative. However, existing microneedle systems are frequently rigid and lack the flexibility needed for extended use, potentially causing irritation, discomfort, and detachment issues when worn over long periods.

The team led by Professor Wonku Kang and Dr. Sohee Jeon of the College of Pharmacy, along with Dr. Jun-Ho Jeong from the College of Medicine at Chung-Ang University, sought to address these critical limitations by drawing inspiration from the barbed and anchoring properties of a bee’s sting. The researchers devised a wearable microneedle patch called Electrospun Web Microneedles (EW-MNs), designed to mimic the unique structural characteristics of a bee sting, which naturally anchors into the skin to deliver venom efficiently and persistently.

The fabrication process of EW-MNs involves an advanced electrospinning technique that deposits ultrafine polymeric nanofibers onto conventional metal microneedles. Electrospinning, a method utilizing a high-voltage electric field to draw charged threads of polymer solutions into fibers with diameters at the nanoscale, produces a dense, interwoven fibrous scaffold around the microneedle tips. This fibrous web forms barbs akin to those found on a bee’s sting, enhancing the microneedle’s grip within the skin tissue and preventing premature detachment during prolonged wear.

These electrospun fibers are not just structural; they impart softness and breathability to the otherwise rigid metal microneedles, reducing skin irritation and improving wearer comfort. The microneedles are mounted onto a flexible adhesive patch with a backing layer, creating an ergonomic design that conforms seamlessly to the patient’s skin. This architecture ensures a stable, continuous, and minimally invasive drug delivery platform, especially critical for chronic neurological conditions where steady medication levels must be maintained without disrupting daily activities.

To validate their design, the research team loaded the EW-MNs with rivastigmine, a cholinesterase inhibitor commonly prescribed for managing Alzheimer’s and Parkinson’s diseases. Animal trials conducted on guinea pigs demonstrated remarkable enhancements in drug absorption compared to conventional transdermal delivery methods. The patches delivered over twice the amount of rivastigmine across a fivefold larger skin surface area, without causing significant discomfort or lasting skin damage. Mild skin irritation observed was transient and resolved promptly after removal, signaling a favorable safety profile.

The sustained and stable drug release from the EW-MN patches owes much to the barbed web structure, which firmly anchors the microneedles within the skin’s outer layers, securing intimate contact between the drug-loaded microneedles and interstitial fluid. This enhanced interface facilitates effective diffusion and absorption of rivastigmine into systemic circulation. Such steady pharmacokinetics mitigate the peaks and troughs commonly associated with oral or standard transdermal administration, potentially improving therapeutic outcomes.

Professor Kang emphasizes the transformative potential of this biomimetic approach, stating that these microneedle patches could redefine patient experiences by rendering needle-related anxieties obsolete. The design encapsulates a synergy between natural mechanisms and engineering prowess, yielding a patient-centric solution that is not only effective but also comfortable and user-friendly. The potential for self-administration further lifts the burden on healthcare systems and caregivers.

Looking beyond neurological disorders, the research team envisions broadening the applicability of EW-MNs to a variety of chronic ailments ranging from diabetes to cardiovascular diseases, where long-term, controlled drug delivery is paramount. Additionally, the technology’s gentle profile is particularly suited for vulnerable populations such as the elderly and children, for whom conventional injection methods pose difficulties. This expanded use could herald a new era of personalized, wearable therapeutics tailored to individual patient needs.

The concept of drawing inspiration from nature’s evolutionary designs is a recurring theme in biomedical engineering, and this study exemplifies how such biomimicry can spark innovations that address clinical shortcomings. By harnessing the bee sting’s anchoring mechanism, the EW-MNs achieve mechanical stability without sacrificing softness or flexibility—traits difficult to reconcile in previous microneedle platforms. This highlights an important direction for future research integrating materials science, nanotechnology, and biology.

Moreover, the incorporation of electrospinning technology underscores the versatility and precision achievable in fabricating therapeutic devices at the nanoscale. The ability to engineer intricate fibrous networks opens pathways to customizing microneedle interfaces to optimize drug release kinetics, skin compatibility, and mechanical adherence. As electrospinning methods advance, future microneedle devices may offer multifunctional platforms capable of delivering vaccines, hormones, or even gene therapies.

This pioneering research, publicly accessible via its DOI link, stands as an inspiring testament to interdisciplinary collaboration, uniting experts in pharmacy, medicine, and engineering at Chung-Ang University. By addressing a common impediment in patient care—the discomfort and inconvenience of injections—this technology brings us closer to a future where therapeutics are seamlessly integrated into daily life. In doing so, it promises to enhance adherence, therapeutic efficiency, and overall quality of life for millions suffering from chronic neurological and other systemic diseases.

In conclusion, the bee sting-inspired EW-MNs developed by Professor Kang and his team represent a significant leap forward in microneedle drug delivery systems. Their innovative design, utilizing electrospun nanofibrous webs to anchor soft microneedles securely in the skin, overcomes previous limitations by combining comfort, efficacy, and longevity. As this platform moves towards clinical applications, it holds the promise of revolutionizing patient-friendly, sustained drug administration, ultimately transforming the landscape of modern therapeutics.

Subject of Research: Animals

Article Title: Bee Stinger-Like Wearable Electrospun Web Microneedles for Sustained CNS Drug

News Publication Date: 31-Jul-2025

References: DOI: 10.1002/adhm.202501371

Image Credits: Professor Wonku Kang from Chung-Ang University

Keywords: Drug delivery, Medical equipment, Pharmaceuticals, Health and medicine, Microfabrication, Biomedical engineering, Disease control, Wearable devices, Biotechnology, Medical technology

The microneedle patch, which utilizes microneedles engineered to penetrate the top layers of skin, collects interstitial fluid – the fluid that surrounds cells in the dermal and epidermal layers. This interstitial fluid contains a wealth of biomarkers that correspond to those typically found in blood samples. Michael Daniele, a professor at NC State and a lead author of the study, emphasizes that utilizing interstitial fluid can streamline the biomarker testing process by eliminating the complexities associated with blood sample preparation.

During their proof-of-concept experiments, the researchers tested the patch on synthetic skin, demonstrating its ability to collect significant amounts of biomarkers within just 15 minutes. Moreover, the patch has been shown to store these samples for up to 24 hours, making it a versatile tool for patients and healthcare providers alike. An important biomarker monitored during testing was cortisol, a hormone that fluctuates with stress levels. The convenience of multiple readings without the pain and inconvenience of blood draws could revolutionize how individuals manage their stress and overall health.

The microneedle patch is made up of four distinct layers: a visible polymer housing, a gel layer, a paper layer for absorption, and the microneedles themselves. Designed to be completely passive, the patch harnesses the properties of the materials used to facilitate fluid transfer. The microneedles contain a material that swells upon contact with interstitial fluid, allowing the fluid to be drawn through the needle and into the paper layer. As the paper becomes saturated, it interfaces with the gel on the opposite side, which contains high concentrations of glycerol. This creates an osmotic pressure differential that facilitates further fluid movement, ultimately enhancing sample collection efficiency.

Dr. Daniele explains that the sample collected in the paper strip can be easily accessed for analysis once the patch is removed, further simplifying testing procedures. The researchers are not only leveraging this technology for cortisol tracking but also envision its application for a broader range of biomarkers found in interstitial fluid. The prospect of easy, pain-free monitoring opens significant avenues for conditions that require frequent testing and evaluation.

Additionally, the microneedle patch can be produced using affordable materials that are readily accessible, making the technology potentially cost-effective compared to traditional blood sample collection methods. Daniele notes, “The highest cost of the patches would be manufacturing the microneedles, but we think the price would be competitive with the costs associated with blood testing.” The elimination of needles, vials, and the need for trained professionals to draw blood presents a strong case for the widespread adoption of this innovative testing method.

The current phase of research includes human testing, with researchers ambitiously developing electronic devices capable of analyzing the samples collected by the microneedle patches. Thus far, a device has been successfully created to read cortisol levels directly from the patch’s paper strip, and efforts are underway to develop technologies for evaluating other biomarkers as well. The future holds promising potential for partnerships within the diagnostic industry to broaden the applications of this technology.

This self-powered microneedle patch represents a significant leap forward in health monitoring technology—a field that has often been stifled by reliance on invasive techniques. By providing a non-invasive alternative that is both efficient and accessible, this innovation could cater to an extensive range of health applications including stress management, chronic disease monitoring, and preventive healthcare measures.

While this technology is still in its infancy, the potential impact on personal health management could be profound. As researchers continue to refine the microneedle patch and explore its capabilities, it paves the way for a future where health monitoring is both comfortable and continuous, fostering an era of smarter, patient-centered healthcare solutions. This approach aligns with the future direction of medical technology, which increasingly emphasizes minimally invasive procedures aimed at enhancing patient comfort and accessibility.

The implications of this technology stretch beyond mere convenience; as health literacy and personal health monitoring become increasingly valued in contemporary society, the microneedle patch can empower individuals to take charge of their health by providing them with the ability to track important biometrics in a seamless fashion. This newfound autonomy could help trigger widespread changes in preventive healthcare and enhance overall public health outcomes over time.

As researchers in this field look for industry partners to bring their innovation to market, the global health community is poised to benefit from advancements like this, which can facilitate timely interventions and informed health decisions. The microneedle patch signifies a move toward the integration of technology in personal health, making monitoring easier and more attainable than ever before.

With continued support from funding agencies and a focus on exploration and development, the researchers at NC State are setting the stage for a technological revolution in health monitoring, one that could reshape our understanding of wellness and disease management. As they engage in human trials and refine the technology for broader applications, the microneedle patch holds the promise of a future where health monitoring can be performed effortlessly, delivering insights that can change lives.

This innovative research has been documented in the open-access paper titled “Design and Characterization of a Self-Powered Microneedle Microfluidic System for Interstitial Fluid Sampling,” published in the journal Lab on a Chip. The collaborative efforts of the researchers, combined with their entrepreneurial aspirations, suggest a future rich with potential for transformative health technologies that enhance the way we monitor and manage health.

Subject of Research: The development and testing of a self-powered microneedle patch for biomarker monitoring through interstitial fluid sampling.
Article Title: Design and Characterization of a Self-Powered Microneedle Microfluidic System for Interstitial Fluid Sampling
News Publication Date: August 1, 2025
Web References: Lab on a Chip Article
References: Not applicable
Image Credits: Michael Daniele, NC State University

Keywords

Non-invasive monitoring, microneedle patch, biomarkers, interstitial fluid, healthcare innovation, cortisol monitoring, chronic disease management, patient-centered technology.