HQ Team
August 10, 2023: A gold-plated nanoscale tattoo-like electronics array can be inserted into live human cells, that in the future can diagnose health problems early, according to researchers at Johns Hopkins University.
The technology allows for the first time the placement of electronics on live cells that stick while flexing and conforming to their wet and fluid outer structure.
“In the future, we would like to have sensors to remotely monitor and control the state of individual cells and the environment surrounding those cells in real-time,” said David Gracias, a professor at Johns Hopkins University, who led the development of the technology.
“If we had technologies to track the health of isolated cells, we could maybe diagnose and treat diseases much earlier and not wait until the entire organ is damaged,” Mr Gracias said.
Barcodes
The tattoos are essentially like barcodes or QR codes and they bridge bridge the gap between living cells or tissue and conventional sensors and electronic materials, Mr Gracias said.
The researchers built the tattoos in the form of arrays with gold, a material known for its ability to prevent signal loss or distortion in electronic wiring.
They attached the arrays to cells that make and sustain tissue in the human body, called fibroblasts.
The arrays were then treated with molecular glues and transferred onto the cells using an alginate hydrogel film, a gel-like laminate that can be dissolved after the gold adheres to the cell.
Stick for 16 hours
The molecular glue on the array bonds to a film secreted by the cells called the extracellular matrix.
The structures were able to stick to soft cells for 16 hours even as the cells moved.
“We’re talking about putting something like an electronic tattoo on a living object tens of times smaller than the head of a pin,” Mr Gracias said. “It’s the first step toward attaching sensors and electronics on live cells.”
Previous research had demonstrated how to use hydrogels to stick nanotechnology onto human skin and internal animal organs.
By showing how to adhere nanowires and nanodots onto single cells, Gracias’ team is addressing the long-standing challenge of making optical sensors and electronics compatible with biological matter at the single-cell level.
“It’s a very important result that the cells can live and move with the tattoos because there’s often a significant incompatibility between living cells and the methods engineers use to fabricate electronics.”
Dots and wires
The team’s ability to attach the dots and wires in an array form is also crucial.
To use this technology to track bioinformation, researchers must be able to arrange sensors and wiring into specific patterns, not unlike how they are arranged in electronic chips.
“This is an array with specific spacing. Not a haphazard bunch of dots,” Mr Gracias said.
The team plans to try to attach more complex nanocircuits that can stay in place for longer periods. They also want to experiment with different types of cells.
