Will Syringes Stick Around?

Syringe manufacturers: You may feel a slight sting in the near future. And the source of this pain can be traced to a rash of recent advancements in microneedle-based drug delivery, which calls into question the viability of traditional needle-and-syringe technologies.

Hypodermic needles have effectively delivered vaccinations and drugs to patients for years. But while they appreciate treatments that keep them healthy, few patients look forward to the pain and anxiety that often accompany the experience. On a larger scale, hypodermic needles pose needle-stick risks and have contributed to the spread of diseases such as hepatitis and HIV through reuse.

Microneedle-based patches and similar technologies, however, could potentially eliminate the drawbacks associated with hypodermic needles while providing more-targeted drug delivery. Microneedle arrays may offer a means of actively delivering large-molecule drugs through the skin--which has been a challenge with existing transdermal patches--and achieving systemic drug delivery. They may also potentially put vaccinations literally in the hands of patients, which could revolutionize treatment in developing countries, as well as on the home front. Ultimately, they promise to provide targeted, painless, nonthreatening, and safe drug delivery.

Before it can reach this potential, though, microneedle technology still requires some work. Making progress on this front are several universities, including Georgia Tech and Emory University. Together, they have created a vaccine-delivery patch that employs a dissolvable microneedle array. When the system is pressed against a patient's skin, the microneedles dissolve in bodily fluids and leave behind only a discardable water-soluble backing. The researchers claim that their patch vaccinates against influenza just as well as, if not better than, a hypodermic needle at a comparable price.

In a similar vein, an Australian research team at the University of Queensland has developed the transdermal Nanopatch. Consisting of an array of 'projections,' the needle-free dissolving vaccination-delivery system is smaller than current microneedle arrays, according to the scientists.

Researchers at North Carolina State, on the other hand, are focusing on infection prevention. Addressing the possibility of infection caused by microneedle penetration of the skin, the scientists incorporate antimicrobial agents into the material from which the arrays are made. Thus, as the microneedles dissolve upon fulfilling their function, they release the antimicrobial agent. The team is exploring the fabrication of the microneedles using the laser-based two-photon polymerization and two-photon polymerization-micromolding processes.

With seemingly limitless advantages, microneedle-based drug-delivery technologies may someday soon supplant the age-old hypodermic needle. If syringe manufacturers aren't investigating or investing in microneedle array development already, they should be. It's definitely worth a shot.