Scientists at the University of California, Los Angeles (UCLA) said the ‘nanospear’ technology – which employs magnets to guide tiny, silicon structures into cells – could lead to rapid, efficient and safe gene delivery targeting applications.
UCLA’s Steven Jonas told us the technology is made using a precision nanomanufacturing process known as ‘patterning nanosphere lithography.’
“To make the nanospheres, our team uses polystyrene beads placed onto a silicon wafer a template,” he explained.
The researchers then used a direct reactive ion etching technique to etch the silicon down onto an array of tiny, spear-shaped structures.
“The beads are then removed and thin layers of nickel and gold are coated onto the spears.”
According to Jonas, the outer gold layer enables the tethering of biomolecules, such as DNA, to the resulting nanospears, which are then removed from the silicon substrate and deployed to their target cells.
“Once removed from the silicon wafer, we take advantage of the magnetic properties of the nickel coating to precisely control the movement and orientation of the nanospears by using a magnet to maneuver the nanospears toward cells in a culture dish,” he said.
By using a handheld magnet – or a rotating magnet from a standard laboratory stir plate – to guide the nanospears to their target cells, researchers eliminate the need for potentially harmful chemical propellants, we were told.
“We are able to manipulate the position, direction, and rotation of one or many nanospears precisely to target cells individually, or to work with large populations of cells,” said Jonas, adding that his team as done as many as 200,000 cells as a time.
According to Jonas, the nanospears can deliver a wide variety of biomolecular payloads.
In a recently published study in journal ACS Nano , the scientists demonstrated “the delivery of a DNA-expression plasmid encoding for a green fluorescent protein, but we envision that nucleic acids, proteins, small molecules, and combinations of these cargo can be packaged and delivered using the nanospears,” he told us.
When compares to traditional viral vectors or electroporation-based methods, the nanospears are very cost effective, said Jonas.
“They are made using nanoscale fabrication methods originating from the semiconductor industry, which are easily scalable for producing large numbers of nanospears.
“Millions of nanospears can be produced from a single silicon wafer at a price less than $500 [€400],” he added.
Lead researchers at UCLA said they are interested in exploring industry partnership opportunities.