Applying ceramic nanoporous microneedle arrays as a transport interface in egg plants and an ex-vivo human skin model

Nanoporous microneedle arrays from Al"2O"3 were fabricated via a micromolding process using a PDMS mold generated via a double replication process from a SU-8/Si-master as a template. Hg-porosity measurements showed that the porosity obtained was a function of the temperature used for sintering, resulting in an average pore diameter of 80nm between 1300 and 1500^oC. Using egg plants it was shown that these nanoporous needles allowed both the delivery of substances, and the extraction of compounds. Subsequently, the delivery of compounds has been evaluated in an ex vivo human skin model using a microneedle array saturated with a labeled monoclonal against a specific marker, DC-SIGN, which is representative for dendritic cells when activated by an antigen. By the latter, it was demonstrated that ceramic nanoporous microneedle arrays are potentially useful for the delivery of vaccines.