Our skin as a platform for healthcare solutions.
The way UT scientist David Fernandez Rivas sees it, our skin – the largest organ in the human body – offers all sorts of untapped possibilities for promoting our health. Earlier this year, he organised a conference on the topic at the University of Twente (The future under our skin). And recently, the Cuban scientist received a substantial starting grant from the European Research Council, (ERC) for his research in the field. Fernandez Rivas focuses his attention on two topics that he believes are related and offer a lot of potential for improved healthcare: needle-free injections and functional tattoos.
‘Our skin tells us a lot about our health, our mind and our environment’, says Rivas. ‘For example, think of how your skin changes colour when you are in love, or stressed out. There is a large amount of information available just below the skin’s surface. With a medical tattoo based on an injection of smart ink, we could create, for example, a handy warning system that changes colour when your skin is about to get sunburned, or that warns you when the glucose balance in your body is disrupted, if you are diabetic. Another possibility is that that of injecting tiny devices under the skin: devices that are invisible to the naked eye, but that collect and release data in response to biomaterials and body processes.’
Central to Fernandez Rivas’ vision is his ground-breaking research into the development of accurate, efficient and reproducible liquid injections without needles. The needle-free injection device he envisions can be used for various applications: additive manufacturing, coatings, and administering medications and vaccines. ‘Injecting thin liquid jets without needles into a soft and heterogeneous substrate, such as human tissue, is not yet properly possible’, he says. ‘We have not yet achieved sufficient precision when it comes to dosage, depth and location under the skin. Our research is focussed on fine-tuning these aspects.’
Discover the benefits of needle-free injecting and how it works in this short video by David Fernandez Rivas
More precision, more personalization
Fernandez Rivas believes that precision is exactly what could become one of the main assets of needle-free injection. ‘The more we learn about the human skin, the more possibilities we see. For example, we now know that our skin reacts differently in the morning than it does in the evening, which means the same injection can have different effects at different times of the day. What’s more, many medicines actually have greater effect just beneath the skin, in the intradermal region, than when they are injected at greater depth. Also, the fact that each person’s skin is different means that with needle-free injections we can offer more personalized treatments. Currently, injections are a relatively unprecise, one-size-fits-all practice. For example, we inject relatively high dosages of a substance deep into the muscle tissue, just because then we can be sure it will have some effect. With needle-free injections, both precision and personalization will increase.’
The needle-free injection technique that Fernandez Rivas and his team are developing is similar to that of an inkjet printer, he says. ‘It is all about creating the right cavity in the skin with the help of a laser. A laser beam – also known as a continuous wave laser – heats the fluid that is to be administered, and then launches droplets through the epidermis at high speed, which then stays in the tissue below. We have already succeeded in launching fluid through the epidermis; now it is a matter of fine-tuning and achieving higher precision.’
Needles came into use as an effective means of penetrating the tough outer layer of our skin. Today, an estimated 12 million needles are used worldwide every day – and thrown away. Fernandez Rivas: ‘Needle-free injections will not make needles completely redundant, but they will make a huge difference: less waste as well as lower risks of contamination and internal damage. And less pain, of course: a needle-free injection is like a mosquito bite – you don’t feel it when it happens, but you sure notice the effects later on.’