Microneedles for Biomedical Applications

Many vaccines are currently administered via intradermal or intramuscular injections; however, immune responses to vaccines can be greatly improved by their administration into the skin without inducing potential toxic effects. Skin possesses many epidermal Langerhans cells and dermal dendritic cells to engage with harmful subjects and orchestrate inflammation. Therefore, there is a need for transdermal drug and vaccine delivery (TDVD) methods.
Being sub-millimetre needle-like structures, microneedles (MNs) have the ability to create mechanical pathways through the stratum corneum (the outermost layer of the skin), providing direct routes for subcutaneous drug delivery that are non-invasive and pain-free. MNs can be microfabricated in various designs using silicon, polysilicon, metal, glass, and polymers. Our focus is to fabricate biocompatible metallic hollow MN arrays for pain-less and potentially self-administrable vaccine delivery. Hollow MNs allow continuous and controlled drug delivery under the skin in a minimally-invasive manner.