What’s happening? Johannes Gutenberg University Mainz (JGU) researchers have created an implantable sensor that can track drug level concentrations by changing colour. The thin, penny-sized device, which can remain in the body for months, contains gold nanoparticles embedded into a porous hydrogel that integrates into body tissue just under the skin. Drug molecules are transported to the sensor via the bloodstream, where they bind to receptors on the nanoparticles’ surface, causing them to change colour. The nanoparticles are infrared so are invisible to the naked eye. Colour changes are detected with a non-invasive measurement device. (Johannes Gutenberg University Mainz, Nano Letters)

Why does this matter? This implant, described as an “invisible tattoo”, has multiple potential applications, including biomarker measurement, drug development, medical research and the enablement of personalised medicine. According to the JGU team, current implantable sensors are only effective for a few days or weeks due to the body rejecting them as a foreign object, alongside instability in their colour changing capabilities. This means frequent surgical procedures are needed to remove and replace them, something that can be reduced should the new device come into clinical use.

People are interested… Health monitoring and more advanced diagnostics were already becoming increasingly popular before Covid-19 hit the globe, and the pandemic has further propelled peoples’ interest. Aside from health apps and wearable devices, other services are out there to help people gain a better insight into their health. Direct-to-consumer genetic tests, for example, can enable them to understand if they are more likely to suffer a future illness and to take action to prevent or reduce their risk.

… and so are governments – Health services are also interested in this approach, as shown by the National Genomics Healthcare Strategy, which launched in the UK last September. Over 10 years, the programme aims to provide population-wide improvements in diagnosis, personalised medicine, disease prevention and research. A pilot trial of a genetic test to predict patients’ cardiovascular disease risk is underway, while some cancer sufferers are already being offered diagnostics to determine if they are more likely to experience serious side effects of chemotherapy drugs.

Covid and beyond – With the Covid-19 pandemic continuing, and many countries experiencing hitches in their vaccine programmes, regular testing for the disease is viewed as essential for identifying hotspots, asymptomatic infections and for moving out of lockdowns. These diagnostics will be a part of everyday life for some time yet, especially as we need to safely visit venues, attend events, travel, head to work or go to school.

With people now being asked to frequently take tests to participate in normal social interaction, it’s not hard to imagine regular testing for other infectious diseases being on the table. In the future, with developments like this from JGU, perhaps the requirement to go to a testing centre will become redundant – we’ll all have implants alerting us when to stay at home and save lives.