Small In Size, But Huge In Applications

"Nanoneedle-based delivery is a powerful new tool for studying biological processes and biophysical properties at the molecular level inside living cells," said Min-Feng Yu, a professor of mechanical science and engineering at the University of Illinois.

To create a nanoneedle, the researchers begin with a rigid but resilient boron-nitride nanotube. The nanotube is then attached to one end of a glass pipette for easy handling, and coated with a thin layer of gold. Molecular cargo is then attached to the gold surface via "linker" molecules. When placed in a cell's cytoplasm or nucleus, the bonds with the linker molecules break, freeing the cargo.

With a diameter of approximately 50 nanometers, the nanoneedle introduces minimal intrusiveness in penetrating cell membranes and accessing the interiors of live cells.

The delivery process can be precisely controlled, monitored and recorded - goals that have not been achieved in prior studies.

"The nanoneedle provides a mechanism by which we can quantitatively examine biological processes occurring within a cell's nucleus or cytoplasm," said Yang Xiang, a professor of molecular and integrative physiology. "By studying how individual proteins and molecules of DNA or RNA mobilize, we can better understand how the system functions as a whole."

Beyond delivery, the nanoneedle-based approach can also be extended in many ways for single-cell studies, said Yu, who also is a researcher at the Center for Nanoscale Chemical-Electrical-Mechanical Manufacturing Systems. "Nanoneedles can be used as electrochemical probes and as optical biosensors to study cellular environments, stimulate certain types of biological sequences, and examine the effect of nanoparticles on cellular physiology."; Source: University of Illinois