Published on July 26, 2010 at 5:01 AM
By Dr Ananya Mandal, MD
Those who fear needles have good news awaiting them. Australian researchers have developed a new method of vaccine delivery using needle-free nano-patches. These could also be mailed to people during pandemics. This breakthrough is published in the latest edition of the journal Small.
According to Professor Mark Kendall, of the University of Queensland's Australian Institute for Biotechnology and Nanotechnology this method has multiple advantages. For one it does not require refrigeration and also reduces the risk of needle-stick injuries to patients or health workers. He said, “That means zero needles, zero sharps, zero opportunity for contamination and zero chance of needle-stick injury…The World Health Organization estimates that 30% of vaccinations in Africa are unsafe due to cross-contamination caused by needle-stick injury… That's a healthcare burden of about $25 per administration.” This nano-patch he explained is smaller than a postage stamp and has 20,000 projections per square centimetre. These tiny projections are made from the dried vaccine that is bound with an excipient, such as carboxymethylcellulose. When the patch is stuck on the skin the projections penetrate the outer skin layer and deliver the biomolecules to the target cells. Dr. Kendall explained that, “Currently most vaccines are delivered with the needle and syringe into muscle, which has few immune cells… In contrast, the skin is abundant in immune cells, offering great potential for vaccines, if we can successfully exploit it with practical delivery devices.” He said that this new device is stable and strong when dry but as soon as it touches the skin the projections become wet, and dissolve within minutes. He enthused that this method is 10 times better than any other method. It will help 10% of the population who have needle phobia. Kendall adds, because it uses one hundred of the dose the cost to the health system is reduced.
This device was based on the initial work done by the team that was published this April in journal PLos One that showed the nano-patch triggered a protective immune response using one-hundredth of the standard needle and syringe dose.
In yet another work by Professor Mark Prausnitz of Georgia Institute of Technology and his team published in last week's Nature Medicine, there is a development of dissolving microneedles. According to Kendall Prausnitz's approach still uses needles for delivery and does not show any real improvement in vaccine immune response over the traditional needle and syringe approach.
The work has been in progress for the last five years and human trials are to begin soon. “We've proven it in the mouse, the next step is to prove it in man,” says Professor Kendall. His collaborators for this work include Professor Ian Frazer and researchers from the University of Melbourne.