Nanowires Inject Molecules Into Living Cells

TechRev_AL writes "A scientist at Harvard University has developed a clever trick for manipulating the insides of living cells. Hongkun Park grows cells on top of nanowires so that the wires poke into them like needles, which allows molecules to be delivered inside them. To use the nanowires to deliver molecules, Park's team first treats them with a chemical that would allow molecules to bind relatively weakly to the surface of the nanowires. Then they coat the wires with a molecule or combination of molecules of interest. When cells are impaled on the nanowires, the molecules are released into the cells' interior. This gallery of images shows the cells growing on top of the nanowires."

Comments

Re:I feel so...

[Sulphur]

I wonder if anything in nature *cough* asbestos *cough* operates similarly by providing ingress to the cell.

Sure beats electroporation...

[aczysz]

As someone who has spent plenty of hours in lab begging my cells to take up whatever GFP protein is the flavor of the week, something like this really could be interesting. As I see it, this would be a whole new class of transfection protocols in addition to chemical and electrical methods. Cost and the idea of actually poking holes makes it more similar to the latter, but it does have some unique differences. The most obvious is that you'd have a broader class of molecules that one can inject since there is practically no membrane interaction. Also, while the plates may be costly, there is no need for an expensive electroporation machine.

Re:Sure beats electroporation...

[radtea]

Like so much stuff coming out of Chemistry groups right now - cute and cool but not likely to be of any real value in the next decade or three.

While I agree with all of that, I'm reminded of Faraday's famous quip when asked what good electricity is: "What good is a baby?"

When people complain about the short-term mindset of the modern world, this is what they're speaking of: we can give individual cells injections! The cool factor alone is worth it, and as someone who has had the misfortune of analying gene expression data from chemically transfected human cell lines I can tell you just the dream of the possibility of being able to mechanically inject cells with interesting molecules puts a smile on my face. The thought of the cells being chemically pristine instead of almost terminally messed up by the transfection process is just delightful.

Think of this as equivalent to a single atom trap: not something that every lab has, but a technique that has allowed us to do some amazing physics by making precision, controlled measurements on a single atom that we couldn't possibly make otherwise.

Re:Completely bypassing the cell's "firewall"?

[aczysz]

This really wouldn't have an potential outside of the lab in terms of pathogenic entry. If you used the technique to inject material into cells that were designed for later human implantation, they would have been transferred to non-spiked surfaces for at least sometime after molecule injection and before implantation. Thus the pathogen's entry point would have been long severed.

Anybody able to give real world application?

[jtollefson]

It would be really good if somebody could explain why this is useful. It sounds like it could be, but, an explanation of practical application would be awesome. =)

Re:Anybody able to give real world application?

[Ledgem]

I'm a graduate student in immunology research, so when I first read this over I immediately began to think about how I could use it in my own research. I can think of quite a few applications.

I won't go into the details of my project (that'd be a few paragraphs right there and I'd lose people's attention), but it's heavily based on cell signaling. In a molecular biology course you were probably exposed to the fact that cells have a whole lot going on inside of them - various receptors trigger various proteins; those proteins alter other proteins (either activating them or shutting them off); proteins can trigger transcription factors, which go to the DNA and influence the protein field... and so on. It can get pretty complicated, but it's like a big puzzle. Pretty fun, as long as your experiments are working properly and you're not in 100% uncharted territory!

The standard way that people map cell signaling pathways is by using inhibitors and stimulators. Generally this means that you want a drug that has a very high specificity, a known target, and a known function. By treating the cell with that drug, you affect one part of the pathway and try to determine what happens to other parts of the signaling pathway. You determine the relationships in that manner. (siRNA is increasingly becoming a standard for "knocking down" targets, as well.)

But how do you get a drug or siRNA plasmid into a cell? With drugs you generally have to culture the cells with them right up to the limit where it's toxic to the cells; with siRNA you need to package it into viruses and then infect your cells (infection rates generally aren't so hot - you could also do electroporesis, but that's a bit stress on the cells). Assuming I'm understanding the reality of the nanotubes correctly and am not totally off in a daydream, this would let you bypass a lot of those concerns and just get your products into the cells pretty easily. I'm not sure what the efficiency of this method would be, but it could be promising.

Just as a disclaimer to any other biologists reading this, I work with primary cells and our cells of interest occur in very low numbers (hence low infection rates and/or methods that stress and kill off large numbers of our cells are very undesirable). People who work with cell lines have it easy! =)