Tiny straws improve molecule delivery

US researchers have found what they believe is a better way to deliver molecules directly into human cells they want to manipulate. 

“Nanostraws” are tiny glass-like protrusions that poke equally tiny holes in cell walls before releasing their cargo and, according to a team from Stanford University, they do if much more safely and efficiently than existing methods.

Materials scientist and team leader Nicholas Melosh says the breakthrough could speed up medical and biological research and one day improve gene therapy for cancer and diseases of the eyes and immune systems.

Melosh’s expertise with nano materials was the key to the new approach, which improves on the process called electroporation, whereby an electric current is used to create holes in cell walls.{%recommended 5547%}

Existing electroporation methods can be imprecise, often killing many of the cells researchers try to work with. Nanostraws are more efficient because their long, narrow profile helps concentrate electric currents into a very small space. 

They’re also a better option than approaches based around using viruses or other chemicals to carry molecules across cell walls.

Melosh and colleagues first tested their technique on animal cells sitting atop a bed of nanostraws. 

When they turned on the electric current, the nanostraws opened tiny, regularly sized pores in the cell membrane: enough to allow molecules in, but not enough to do serious damage. The current drew molecules straight into the cell, further increasing the speed and precision of the process. 

The question at that time was whether the technique would be as effective on the kinds of human cells clinicians would need to manipulate to treat diseases.

In a paper published in the journal Science Advances, the researchers report that the answer is yes. They successfully delivered molecules into three human cell types as well as mouse brain cells, all of which had proved difficult to work with in the past.

The technique was quick and killed fewer than 10% of cells, a vast improvement on standard electroporation, they say.

The next step is to test it with human immune cells, which are among the hardest to work with.

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