Engineers use droplet microfluidics to create glucose-sensing microbeads
Tiny beads may act as minimally invasive glucose sensors for a variety of applications in cell culture systems and tissue engineering
Cell cultures need glucose for energy, but too much sugar can create a diabetic-like environment in which cell proteins undergo unwanted structural changes. Standard methods to monitor glucose levels require invasive and time-consuming handling of the cell culture.
A team of engineers at the National University of Singapore and Singapore's Institute of Microelectronics is developing an alternative approach that takes advantage of new microfluidic techniques. In a continuous and controlled process, the researchers created small droplets of polymer that encapsulated pairs of fluorescing molecules. These microbeads can be added to cell cultures where, in the presence of glucose, they emit a stronger fluorescent signal.
The team demonstrated the glucose sensing abilities of the microbeads across the normal physiological range, as reported in the American Institute of Physics' (AIP) journal Biomicrofluidics.
"The method is simple, inexpensive, and produces glucose-sensing microbeads of different sizes," says Dieter Trau, assistant professor in the Departments of Bioengineering and Chemical & Biomolecular Engineering at the National University of Singapore. "Our work automates the process of microbead preparation onto a single narrow chip with minimal use of reagents. Sensing microbeads can act as small, minimally invasive glucose sensors and be optically integrated in cell culture systems to monitor glucose levels. These microbeads have the potential to detect the local glucose concentration in the microenvironment around a cell, as well as gradual changes due to cell metabolism."