Scientists have developed an implantable sensor using gold nanoparticles, which can function in the human body for “several months” to report health changes
Scientists at Johannes Gutenberg University Mainz (JGU) have been working on a novel implantable sensor, which would be used to report changes in drug concentration by changing colour.
“Our sensor is like an invisible tattoo, not much bigger than a penny and thinner than one millimeter,” said Professor Carsten Soennichsen, head of the Nanobiotechnology Group at JGU.
Firstly, what is an implantable sensor?
While implantable sensors are often regarded with suspicion by the internet, in reality they’re something quite different.
In medicine, implantable sensors continuously transmit information on vital values and concentrations of substances or drugs in the body.
Implantable sensors give healthcare professionals a way to monitor disease progression and how well treatments are working. Unfortunately, normal implantable sensors need replacement after a few days or weeks – meaning that the new discovery of a few months could change how sensors work entirely.
Secondly, why use gold nanoparticles?
Gold nanoparticles act as small antennas for light: They strongly absorb and scatter it and, therefore, appear colourful. They react to alterations in their surrounding by changing colours, which led to the research team deciding to exploit this trait for the sake of implantable sensors.
“We are used to colored objects bleaching over time. Gold nanoparticles, however, do not bleach but keep their color permanently. As they can be easily coated with various different receptors, they are an ideal platform for implantable sensors,” said Dr Katharina Kaefer, first author of the study.
In future, gold nanoparticle-based implantable sensors could be used to observe concentrations of different biomarkers or drugs in the body simultaneously. Such sensors could find application in drug development, medical research, or personalized medicine, such as the management of chronic diseases.
Thirdly, how did scientists stop the body rejection the sensor?
To prevent the tiny particles from swimming away or being degraded by immune cells, they are embedded in a porous hydrogel.
Once implanted under the skin, small blood vessels and cells grow into the pores. This means that the sensor is integrated in the tissue and is not rejected as a foreign body.
Since the gold nanoparticles are infrared, they are not actually visible to the human eye. However, a special kind of measurement device can detect their colour noninvasively through the skin.
Finally, what could this mean for medicine?
A gold nanoparticle implantable sensor could be used throughout various fields – in cancer treatment, or in virus observation.
This could now be used to observe concentrations of different biomarkers or drugs in the body at the same time. Such sensors could find application in drug development, medical research, or personalised medicine.
When it comes to chronic diseases, neuromodulation is already an experimental form of handling severe depression. This new sensor could create similarly innovative possibilities.