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"DNA Origami" Could Allow For Controlled Drug Delivery
esinclair writes "As reported in Nature News, researchers have designed a method which allows DNA strands to be formed into cubes and other designs by oligonucleotides. The uses of this DNA origami are still being developed. One possibility for them is to be used as a drug-delivery system. The fact that scientists have also come up with a method to lock these structures and use 'keys' to unlock them would conceivably allow for a controlled delivery system."
Sure, if you want to give the immune system a heart-attack, grossly over complicate something that can be done better/faster/cheaper with dendrimers, and... what was the advantage of doing this again?
DNA Rights Management... Write your MEP's now!
--- I am known for the ones who want to find me on the net. Is that a privacy risk or a privilege? One might wonder..
As a biochemist working in the area of structure/physics, of course I find this very interesting, and there's no shortage of things that could be said about this technique.
However, one of the most relevant issues in biotech and nanotech is the question of cost. The most elegant drug delivery system in the world will never be viable if you can't produce it in decent yields, at a reasonable cost.
My work involves viral capsids, which we use as nano building blocks because they (sometimes) self-assemble, making very large, symmetric structures with relative ease. However, you still have to produce the protein, which usually involves engineering some other organism to produce it for you, since it can't be done synthetically. Assuming that step can be accomplished, you still must purify it, and hope that once all is said and done the protein has retained the appropriate structure. If it's been "deformed" along the way, it's usually a one-way street, and your precious product is now garbage.
In contrast, DNA can be made more or less fully synthetically, and the misfolding problem is a non-issue: it can be melted down and re-folded nearly infinitely.
Those features make DNA really interesting as a better candidate for commercially-viable nanotech. On the other hand, DNA is going to be uniformly negatively charged everywhere, as opposed to proteins which can take on nearly any characteristic you might want, due to the range of amino acid building blocks. In a biological sense such as the article mentions, that could be a concern if you want it to interact with (or avoid) other structures.
DNA Origami was given a comical name for a reason. This is just a curiosity. Maybe some day the technique will be used for something practical.. but more likely DNA synthesis technology will catch up and there will no longer be any need to "fold" an existing long single strand of DNA like a virus. It's actually more like "stapling" and that's how it is described in the literature, maybe they should have called it Milton Manipulation, but I guess few biologists would get the joke.
It's truly frightening that the vast majority of military spending that has gone into "nanotechnology" has been directed towards the Design-Ahead-ists, those who follow the wisdom of K. Eric Drexler. It's the new cold war, and its even colder than the last. Technology like DNA Origami and Ralph Merkle's continuing pursuit of STM/AFM techniques are literally the sparks that could ignite a Gray Goo Armageddon - or the abundant life.
How we know is more important than what we know.
Lots of things *could* be used for drug delivery. How about demonstrating that things can be put into and taken out of these boxes before jumping to conclusions?
Protein capsules which can be opened and closed have been tested for more than 20 years. Loading those things with concentrated enough drugs to make them work has not been too easy.
All your DNA base (pairs) do belong to us
http://www.cs.duke.edu/~nikhil/.fnano09/u34bu3r/Self-AssembledDNANanostructures/PDF/For%20Review/E00-668912817.pdf
Yeah, fuck you Nature.
How we know is more important than what we know.
Sigh.
How we know is more important than what we know.
Can they make a crane or not?
The "DNA origami" are artificial strands of DNA that are held together at specific locations by staple strands. The strands are made to order from a commercial source. Software we wrote allows us to draw arbitrary (3D and 2D) shapes and have the purchase order automatically generated! It's really a wonderful nanotechnology, ideal for aqueous based situations where specific scale and proximity is required. Drug delivery is not the ideal application but for some reason this author seemed to think so. Specific aptamers allow us to bind a variety of things to the origami including fluorescent dyes, proteins, and other nanoparticles. Two important points: 1. Have no fear of the Grey Goo from this one. Particular DNA strands need to be added for the structures to grow. Self assembly yes but only with the added (and unnatural) building blocks. 2. Our work on DNA "origami" is funded by the NIH. Sorry, no black helicopters. Please feel free to read to your heart's content and contribute if you are able: http://www.biodesign.asu.edu/centers/smb/
Can I have a cube of DNA-25?
I wish someone would deliver some to me.
http://heybryan.org/books/papers/Self-assembly%20of%20a%20nanoscale%20DNA%20box%20with%20a%20controllable%20lid.pdf
Thanks kanzure, you rock.
How we know is more important than what we know.
Very interesting and promising idea. Especially if design of this structures is possible "in silico". Since last few years , we can notice great progress in this area.
Irritating about speaking of this kind of research and achievement is that every time when they design nano-structure always first application of this have drug connection. Of course it looks good in newspapers, but unfortunately it obscures application that it can achieve in near future.
The reasons, why to applicate this in drugs delivery in near future will be very hard, are :
+ putting drug inside box. It was shown that oligonucleotides can self-assembly but there were nothing about how to put drug molecule inside. Of course it is possible to build some empty boxes but it increases cost, and decreases efficiency of therapy. It can be easily solved if box could not be able to assembly in absence of (drug)molecule
+ The big problem is deliver box to specific place in organism. It's obvious that main target of this type of nano-structures are cells, because deliver to drug outside an cell (e.g: lymph) is not a problem. Cells are protected from free transport of compounds like proteins, nucleic acids etc. through lipid bilayer. If box wants to go through bilayer, its designer should "decorate" it using some other compounds. Then the risk of immune response increases.
+ some other problems mentioned by authors of this research.
But Andersen et.al. made big step forward.