Media release

From: Springer Nature

A compound that enables the delivery of insulin through the skin is demonstrated in mice and minipigs. The findings, reported in a paper published in Nature, suggest a potential alternative to injection for diabetes management and may support broader applications in other therapeutics.

Drug delivery through skin is widely used for small molecules owing to its convenience and patient compliance. However, the structure of the skin presents a barrier to larger molecules such as proteins and peptides. Existing methods to enhance skin permeability, including microneedles, ultrasound, and chemical agents, are often invasive and compromise skin integrity, which limits their clinical utility.

Rongjun Chen, Youqing Shen, Jiajia Xiang, Ruhong Zhou and colleagues report a fast skin-permeable polymer called poly[2-(N-oxide-N,N-dimethylamino)ethyl methacrylate] (OP), which can penetrate through different layers of skin through interactions with the skin’s changing pH gradient. When combined with insulin, OP facilitates its transport through the skin into systemic circulation and its accumulation in key glucose-regulating tissues, including the liver and skeletal muscles. In diabetic mice and minipigs, application of OP–insulin to the skin lowered blood glucose levels to the normal range within 1–2 hours, which is comparable to the effect of injected insulin, and maintained the normal level for up to 12 hours. No adverse effects were observed in skin cells, blood cells or in the functions of organs including the liver and kidney.

The study demonstrates that OP could achieve skin permeation without disrupting skin structures, and that insulin combined with OP maintains its biological activity. Although further investigation is needed to assess long-term safety, dose control and potential clinical application, the strategy may offer a novel and versatile platform for non-invasive delivery of other biomacromolecules.