Microneedles' Device: Design, Fabrication, and Applications

The delivery of therapeutical molecules through the skin, particularly to its deeper layers, is impaired due to the stratum corneum layer, which acts as a barrier to foreign substances. Thus, for the past years, scientists have focused on the development of more efficient methods to deliver molecules to skin distinct layers. Microneedles, as a new class of biomedical devices, consist of an array of microscale needles. This particular biomedical device has been drawing attention due to its ability to breach the stratum corneum, forming micro-conduits to facilitate the passage of therapeutical molecules. The microneedle device has several advantages over conventional methods, such as better medication adherence, easiness, and painless self-administration. Moreover, it is possible to deliver the molecules swiftly or over time. Microneedles can vary in shape, size, and composition. The design process of a microneedle device must take into account several factors, like the location delivery, the material, and the manufacturing process. Microneedles have been used in a large number of fields from drug and vaccine application to cosmetics, therapy, diagnoses, tissue engineering, sample extraction, cancer research, and wound healing, among others.