One drug delivery idea is to create a biodegradable needle made of a particular drug, inject the needle into the body and leave it there to dissolve.
The trouble is that nobody has perfected a way of making needles out of pharmaceuticals, at least not ones that are sharp and narrow enough not to cause pain, as well as long and strong enough to penetrate the epidermis, which is about 50 micrometres thick, on average.
But Hyung Il Jung at Yonsei University
in Seoul, South Korea, has hit upon an idea that could change this. He and a colleague say that solid microneedles can be made by mixing a drug with a sticky syrup-like substance, which is coated in a thin layer onto a substrate. This can be drawn into a needle shape by touching it from above with a pointed object and then drawing out the mixture by lifting that point, like touching syrup with your finger.
This creates a thin and narrow "needle" up to several hundred micrometres long, which is then cured to make it hard. By bringing several points into contact with the surface, it is possible to create an array of needles like the head of a brush. Hyung Il Jung says these needles can be injected without pain and will biodegrade quickly to release whatever drug they are carrying directly into the body.
Read the full dissolving hypodermic needles
patent application.Justin Mullins, New Scientist consultant
Labels: health, materials