Nanoporous microneedle arrays seamlessly connected to a drug reservoir for tunable transdermal delivery of memantine.

Conventional transdermal drug patches have been on the market since 1997 but their applicability for drug delivery is limited: currently only nearly two dozen of molecules have been approved by the regulatory authorities for transdermal administration and have reached the market. The possibilities for drug delivery via the skin can be improved and expanded by using microneedle patch technologies. However, most microneedle patches focus on the delivery of low amounts of drugs that are generally very potent due to the small dimensions of the microneedle systems.

Vaccination with influenza hemagglutinin-loaded ceramic nanoporous microneedle arrays induces protective immune responses.

Microneedle arrays (MNAs) are a promising mean to administer vaccines. Without the need of highly trained personnel, MNAs can be applied to deliver vaccines into the dermis, which is well equipped to initiate potent immune responses. While vaccination using dissolving microneedle arrays has been extensively investigated, the use of solid nanoporous MNAs (npMNAs) to deliver vaccines remained largely unexplored.

Nanoporous Microneedle Arrays Effectively Induce Antibody Responses against Diphtheria and Tetanus Toxoid.

The skin is immunologically very potent because of the high number of antigen-presenting cells in the dermis and epidermis, and is therefore considered to be very suitable for vaccination. However, the skin's physical barrier, the stratum corneum, prevents foreign substances, including vaccines, from entering the skin. Microneedles, which are needle-like structures with dimensions in the micrometer range, form a relatively new approach to circumvent the stratum corneum, allowing for minimally invasive and pain-free vaccination.

Microneedle-based drug and vaccine delivery via nanoporous microneedle arrays.

In the literature, several types of microneedles have been extensively described. However, porous microneedle arrays only received minimal attention. Hence, only little is known about drug delivery via these microneedles.