Microneedle Array Integrated With CNT Nanofilters for Controlled and Selective Drug Delivery

An innovative process of integrating microneedle array with carbon nanotube (CNT) nanofilters is developed for a novel transdermal drug delivery device with nanometer-scale selectivity and control mechanism. The SU-8 microneedle array is fabricated by the double drawing lithography process. This microneedle array is capable of penetrating stratum corneum (SC) layer. Then, drug molecules can selectively pass through CNT nanofilters with the aid of pressure, or an electric field, and are effectively delivered into the tissues under the SC layer. The CNT bundles integrated within the microneedle array act as nanofilters to block particles and molecules larger than the inner diameter of the CNTs. Moreover, the CNT nanofilters can selectively control the delivered drugs when they are under various electric fields. Three kinds of biomolecules, e.g., glucose, insulin, and hemagglutininare are investigated. The results demonstrate that the proposed novel transdermal drug delivery device can effectively deliver drug molecules in a selectively control mechanism.