Biomedical Applications of Polymeric Microneedles for Transdermal Therapeutic Delivery and Diagnosis: Current Status and Future Perspectives

Transdermal drug delivery is a crucial extension of drug administration routes and has been widely acknowledged as an alternative way to traditional oral administration and subcutaneous injections due to the advantages such as increased dosage efficacy, decreased systemic side effect, and improved patient compliance. The past few decades have witnessed biomedical applications of microneedles in various cutting-edge fields. Microneedles are needles with micron-scale length which can pierce the epidermis of the skin in a minimally invasive manner for transdermal drug delivery. Compared with inorganic and metal microneedles, polymeric microneedles have attracted more attention because of their superior biocompatibility, nontoxicity, and biodegradability. In this review, the state-of-art and future biomedical applications of polymeric microneedles are summarized. First of all, a brief introduction to the polymeric microneedles, including types of polymeric microneedles and methods for the fabrication is included. Then the biomedical applications of polymeric microneedles in transdermal drug delivery and diagnosis are summarized in detail. Finally, discussions on the current limitations and future perspectives of polymeric microneedles are provided.