Baroreceptor-inspired microneedle skin patch for pressure-controlled drug release

In the field of biomedical engineering, the pursuit of innovative solutions for precise and controlled drug delivery has been a significant research focus. Traditional methods of transdermal drug administration often lack spatiotemporal control, leading to skin irritation, drug resistance, and inefficiencies. However, recent advancements in microneedle (MN) technology have paved the way for more effective and user-friendly drug delivery systems. Recently, researchers from the City University of Hong Kong have developed a groundbreaking baroreceptor-inspired microneedle (MN) skin patch that revolutionizes pressure-controlled drug delivery. This innovative device, published in BME Frontiers, promises to significantly improve the treatment of chronic skin diseases and other conditions requiring precise and timely transdermal medication.

Inspiration
The new MN skin patch is inspired by the skin baroreceptors, mechanosensitive elements of the peripheral nervous system that trigger unconscious responses to stress or temperature changes. By mimicking these receptors, the researchers have created a device that responds to finger touching, providing a fast, user-friendly, and potentially minimally invasive drug administration method.

Dual-Layer Design for Precision

The baroreceptor-inspired MN skin patch features a unique dual-layer design, consisting of drug-containing microneedles and a stretchable electrode array. The electrode array, integrated with a piezoconductive switch and a flexible battery, delivers a mild electric current only at the spot that is pressed. This allows for spatially and temporally controlled drug release, significantly enhancing the precision and effectiveness of treatment.

Efficient Drug Delivery

The device's efficacy has been demonstrated through experiments using Cy3 dye and insulin as model drugs. In tests on pig skin, the MN skin patch delivered Cy3 dye with a fluorescence intensity approximately eight times higher than passive delivery methods. Similarly, in mouse models, the device successfully delivered insulin, resulting in a reduction in blood glucose levels. Compared to passive delivery without pressing, the dosage of drugs released by the device was 2.83 times higher.

Broad Applications and Future Prospects

The baroreceptor-inspired MN skin patch has numerous potential applications, including the treatment of chronic skin diseases, pain management, and even targeted drug delivery for cancer therapy. Its ability to deliver drugs precisely and on demand makes it an attractive alternative to traditional methods that often lack spatiotemporal control, leading to skin irritation or drug resistance issues.

"This device represents a significant step forward in the field of biomimetic microneedle technology," said Dr. Chenjie Xu, lead researcher of the study. "By mimicking the natural mechanisms of the skin baroreceptors, we have created a user-friendly and highly effective drug delivery system that has the potential to transform the way we treat a wide range of conditions."

The research team includes Jiahui He, Mengjia Zheng, Tianli Hu, Ya Huang, Jingyou Su, Chunyi Zhi, Xinge Yu, and Chenjie Xu from the Department of Biomedical Engineering at City University of Hong Kong.

The General Research Fund (GRF) grant from the Research Grants Council (RGC) of the Hong Kong Special Administrative Region China (CityU11200820, CityU11100323) and the Mainland/Hong Kong Joint Research Scheme sponsored by the RGC Hong Kong and the National Natural Science Foundation of China (N_CityU118/20) supported the research.