Microfabricated microneedles for gene and drug delivery

By incorporating techniques adapted from the microelectronics industry, the field of microfabrication has allowed the creation of microneedles, which have the potential to improve existing biological-laboratory and medical de vices and to enable novel devices for gene and drug delivery. Dense arrays of microneedles have been used to deliver DNA into cells. Many cells are tr eated at once, which is much more efficient than current microinjection tec hniques. Microneedles have also been used to deliver drugs into local regio ns of tissue. Microfabricated neural probes have delivered drugs into neura l tissue while simultaneously stimulating and recording neuronal activity, and microneedles have been inserted into arterial vessel walls to deliver a nti-restenosis drugs. Finally, microhypodermic needles and microneedles for transdermal drug delivery have been developed to reduce needle insertion p ain and tissue trauma and to provide controlled delivery across the skin. T hese needles have been shown to be robust enough to penetrate skin and dram atically increase skin permeability to macromolecules.