Advances in magnetic microneedles: From fabrications to applications

Microneedles (MNs) are a new type of physically facilitated penetration technology that not only allows for transdermal drug delivery in a minimally invasive and painless manner, but also serves as a channel for biosignal sensing, demonstrating great potential for application in the medical field. Magnetic materials consist of magnetic elements and their compounds, which can be used for separation, diagnosis, drug delivery and other applications in the fields of medicine, biology and materials. Combining magnetic materials with microneedles can confer magnetic responsiveness to microneedles. Specific strategies for magnetic introduction, corresponding synthetic methods, related applications, and comparisons with other externally stimulus-responsive microneedles are reviewed in this paper on magnetic microneedles. In the end, the limitations of current research and the potential for development of magnetically responsive microneedles are discussed. We hope that the description of magnetic microneedle synthesis methods and related applications in this paper will provide readers with a better understanding of magnetic microneedle systems and inspire the development of novel magnetic microneedle products.