Nanotattoos: Monitoring analytes in vivo with biocompatible and biodegradable fluorescent nanosensors

Fluorescent nanosensors have been developed that can detect and monitor in vivo physiological analytes such as sodium and glucose (1,2). These sensors have the potential for use as a powerful in vivo monitoring tool with both clinical and research applications; however, the sensor probe typically consists of plasticized polyvinyl chloride (PVC) whose use in medical devices has raised health concerns. In response to these safety concerns, we have developed fluorescent nanosensors that have biocompatible and biodegradable probe components. The sensors are designed to monitor sodium because of its importance in physiological conditions, such as hyponatremia and dehydration. Similar to their plasticized PVC-based counterparts, these sensors were tailored to respond at extracellular sodium concentrations, they did not experience interference from extracellular potassium concentrations, and they have a lifetime of at least 14 days in solution. In addition, we performed biodistribution studies in mice and saw evidence of sensor accumulation in the liver and spleen, but no accumulation in the kidneys and lungs. The development of functional biodegradable sensors will allow for their reapplication similar to a tattoo without the long-term toxic side-effects from sensor accumulation in the body.

1. Dubach, J. M., et al. In Vivo Sodium Concentration Continuously Monitored With Fluorescent Sensors. Integr Biol 3, 142-148 (2011).
2. Billingsley, K. L. et al. Fluorescent Nano-Optodes for Glucose Detection. Anal Chem 82, 3707-3713 (2010).