Barely visible needles, also known as microneedles, are well on the way to ushering in a new, painless era of injections and blood tests. Regardless of whether they are part of a syringe or attached to a plaster, microneedles have a decisive advantage: They minimize pain because they do not come into contact with the nerve endings in the deeper layers of the skin. Because the needles are usually only 50 to 2000 micrometers long and could therefore at most pierce a typical sheet of paper and 1 to 100 micrometers wide, roughly like a human hair.
They prevent unpleasant pain because they only penetrate the dead, uppermost layer of skin in order to penetrate the epidermis below. This layer is made up of living cells surrounded by what is known as interstitial fluid. In contrast, the microscopically thin needles barely or not at all penetrate the even deeper dermis. And only there are the nerve endings that can be stimulated and activated by a needle – together with blood and lymph vessels – below.
The most exciting technological innovations of 2020
What technical advances have the potential to revolutionize healthcare, entire branches of industry or even societies in three to five years? The ten best out of 75 nominated »Innovations of the Year 2020« were selected by a team of experts, convened by the World Economic Forum and the US science magazine »Scientific American«.
We present the top 10 in the last two weeks of the year:
- Medicine: The painless spades
- Chemie: The sun turns carbon dioxide into a raw material
- Clinical research: Virtual patients should revolutionize medicine
- Spatial Computing: The digital and analog world are merging
- Digital medicine: Detect and treat diseases with apps
- Electric aviation: Flying climate-friendly at last
- Quantensensoren: Measure the world with the highest precision
- Climate sinner cement: The building material can be produced in a climate-friendly manner
- Green fuel: Hydrogen energy without greenhouse gases
- Synthetic Biology: A powerhouse of genetic information
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Microneedle syringes and plasters are already used to give vaccines. Clinical studies are currently testing whether they are suitable for the treatment of diabetes and cancer or help against neuropathic pain that can be caused by damage to the nervous system. Medicines can be administered much more efficiently with the needles than with transdermal patches, for example. These are plasters with a drug incorporated into the adhesive side. The active ingredients diffuse from there and are absorbed into the skin.
Most recently, researchers have presented a method for treating skin diseases such as psoriasis, warts and certain types of cancer: they mixed therapeutic creams or gels with star-shaped constructs made from microneedles. The needles gently perforate the surface of the skin and allow the therapeutic agent to more easily get through the top layer of skin.
On the way to application
Many products with microneedles are on their way to commercial use: as a fast, painless tool for use in diagnostic tests or for monitoring health parameters and to collect blood or interstitial fluid. This works because the tiny holes that are poked by the needles locally change the pressure in the epidermis or dermis so that the interstitial fluid or blood is forced into a collection container. If the needles are coupled with biosensors, the devices can measure biological markers within minutes, e.g. glucose values, cholesterol, alcohol, breakdown products of active substances or immune cells.
For example, some products allow blood samples to be collected at home, which a healthcare professional would normally need to take. At least one such product has already cleared the regulatory hurdles for such use: in the US and the EU, the Seventh Sense Biosystems “TAP” blood collection device authorized. This enables laypeople to take small blood samples themselves and then either send them to a laboratory or analyze them on site. In research, microneedles are also connected to wireless communication devices.
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