[Applications of microneedles in non-transdermal drug delivery: a review].

In recent years, microneedles have emerged as a drug delivery technology that holds great research value and application potential due to their minimally invasive, painless, user-friendly, and efficient characteristics. The technology of microneedles has rapidly evolved over the past 20 years, allowing customization of shape, composition, mechanical properties, and unique functions to meet diverse needs. With the ability to minimally invasively traverse various biological barriers, researchers have explored the applications of microneedles in various tissues and organs beyond the skin. This article summarizes the research progress on the use of microneedles for drug delivery in tissues such as eyes, blood vessel, and heart. By presenting these cutting-edge research to readers, we hope to promote the development and application of microneedle technology.