Safety Demonstration of Microneedle Insertion

Hypodermic needles are conventionally used to deliver drugs and vaccines into the muscle of humans and animals. Side effects of these needle injections are pain, bleeding, and anxiety in patients. An alternative drug and vaccine delivery method is the use of hollow microneedles, which are sub-millimeter needle-like structures. Microneedles are pain- and bleeding-free, as they do not reach the nerve-endings and blood capillaries in the skin. As a result, they are better received by patients and do not induce needle anxiety. As the investigators' microneedles are made of gold- or silver-coated, as well as uncoated nickel, the purpose of this study is to observe their biocompatibility and inertness.