Nanoscale Tattoos That Track the Health of Individual Cells Can Provide Early Warning for Medical Problems

Scientists have developed a new method of monitoring individual cells using nanoscale tattoos. The technology involves inserting cells with tiny particles that release light upon contacting specific molecules.

A New Form of Art

The tattoos are composed of dots and wires that can adhere to living cells. This technology is the first in the industry to allow optical elements or electronics placed on live cells while conforming to their wet and fluid outer structure.

Professor David Gracias from Johns Hopkins University led the researchers to create the tattoos as arrays with gold, which prevents signal loss or alteration in electronic swing. The gold arrays are attached to cells, which make and sustain tissue in the human body called fibroblast. Upon treatment with molecular glues, the arrays are transferred onto the cells using an alginate hydrogel film which dissolves after the gold is attached to the cell.

Previous research studies have successfully demonstrated the role of hydrogels in sticking nanotechnology onto human skin and the internal organs of animals. However, it has been a challenge to make optical sensors and electronics that shows compatibility with biological materials at the cellular level. Gracias addressed this long-standing challenge, and his team as they demonstrated the process of adhering nanowires and nanodots onto individual cells.

The tattoos work by bridging the gap between living cells or tissues and conventional sensors and electronic devices. They can adhere to soft cells for 16 hours even if the cells are moving.

Gracias ensures that while they demonstrate the possibility of attaching complex nanopatterns to living cells, they also ensure that the cells do not die. Allowing the cells to live and move with the tattoos is crucial because there is a significant incompatibility between living cells and scientists' electronic fabrication methods.

Attaching the dots and wires in an array form is also crucial since the scientists need to ensure that this technology can be used to track bio information. To make this possible, the sensors and wiring were arranged into specific patterns, unlike when placed in electronic chips.

This breakthrough allows researchers to remotely track and control single cells' state and the environment surrounding them. Tracking the health of isolated cells can offer a new way of diagnosing and treating diseases much earlier.

Role of Hydrogel in Nanotechnology

A hydrogel is a three-dimensional network of gel structures made of cross-linked polymers. It resembles a solid material but absorbs and retains water, making it appear soft and moist. The composition and arrangement of polymers allow the hydrogels to exhibit a wide array of mechanical, structural, and chemical properties.

Hydrogels have unique characteristics which make them useful in nanotechnology, including their small size effect, surface effect, and quantum effect. As the noble metal nanoparticles are loaded into a 3D network of hydrogels, the synergy of the components is enhanced. Hydrogels can also be modified to prepare intelligent materials that recognize external stimuli. Most of all, combining noble metal nanoparticles and hydrogels can create new composite materials with valuable applications in making sensors.