Polymeric 3D‐Printed Microneedle Arrays for Non‐Transdermal Drug Delivery and Diagnostics

Microneedle arrays (MNAs) are gaining interest for their potential in simple drug delivery and diagnostics. Thanks to improvements in three-dimensional (3D) printing, MNAs can now be created with high precision, complex shapes, and customizable features, which broadens their medical applications. Most research has looked at transdermal uses, but non-transdermal applications are still not fully explored. This review provides an overview of recent advances in non-transdermal 3D-printed MNAs for drug delivery and diagnostics. A literature search, focusing on studies published in the last decade is conducted. The applications are categorized by target site, including the brain/ central nervous system (CNS), oral cavity, eyes, gastrointestinal (GI) tract, cardiovascular system, reproductive system, and other emerging areas. The findings show that 3D-printed MNAs can be used beyond skin delivery. They highlight new applications across various tissues and systems. This less-explored area has great potential for future clinical use. More research is needed to address challenges like material, fabrication, and regulatory issues to make sure that polymeric 3D printed non-transdermal MNAs can be successfully implemented in modern healthcare.