Corante

About this Author
DBL%20Hendrix%20small.png College chemistry, 1983

Derek Lowe The 2002 Model

Dbl%20new%20portrait%20B%26W.png After 10 years of blogging. . .

Derek Lowe, an Arkansan by birth, got his BA from Hendrix College and his PhD in organic chemistry from Duke before spending time in Germany on a Humboldt Fellowship on his post-doc. He's worked for several major pharmaceutical companies since 1989 on drug discovery projects against schizophrenia, Alzheimer's, diabetes, osteoporosis and other diseases. To contact Derek email him directly: derekb.lowe@gmail.com Twitter: Dereklowe

Chemistry and Drug Data: Drugbank
Emolecules
ChemSpider
Chempedia Lab
Synthetic Pages
Organic Chemistry Portal
PubChem
Not Voodoo
DailyMed
Druglib
Clinicaltrials.gov

Chemistry and Pharma Blogs:
Org Prep Daily
The Haystack
Kilomentor
A New Merck, Reviewed
Liberal Arts Chemistry
Electron Pusher
All Things Metathesis
C&E News Blogs
Chemiotics II
Chemical Space
Noel O'Blog
In Vivo Blog
Terra Sigilatta
BBSRC/Douglas Kell
ChemBark
Realizations in Biostatistics
Chemjobber
Pharmalot
ChemSpider Blog
Pharmagossip
Med-Chemist
Organic Chem - Education & Industry
Pharma Strategy Blog
No Name No Slogan
Practical Fragments
SimBioSys
The Curious Wavefunction
Natural Product Man
Fragment Literature
Chemistry World Blog
Synthetic Nature
Chemistry Blog
Synthesizing Ideas
Business|Bytes|Genes|Molecules
Eye on FDA
Chemical Forums
Depth-First
Symyx Blog
Sceptical Chymist
Lamentations on Chemistry
Computational Organic Chemistry
Mining Drugs
Henry Rzepa


Science Blogs and News:
Bad Science
The Loom
Uncertain Principles
Fierce Biotech
Blogs for Industry
Omics! Omics!
Young Female Scientist
Notional Slurry
Nobel Intent
SciTech Daily
Science Blog
FuturePundit
Aetiology
Gene Expression (I)
Gene Expression (II)
Sciencebase
Pharyngula
Adventures in Ethics and Science
Transterrestrial Musings
Slashdot Science
Cosmic Variance
Biology News Net


Medical Blogs
DB's Medical Rants
Science-Based Medicine
GruntDoc
Respectful Insolence
Diabetes Mine


Economics and Business
Marginal Revolution
The Volokh Conspiracy
Knowledge Problem


Politics / Current Events
Virginia Postrel
Instapundit
Belmont Club
Mickey Kaus


Belles Lettres
Uncouth Reflections
Arts and Letters Daily
In the Pipeline: Don't miss Derek Lowe's excellent commentary on drug discovery and the pharma industry in general at In the Pipeline

In the Pipeline

« You Mean You Don't Have to Buy Them? | Main | Four Med-Chem Questions »

October 28, 2009

Nanotech Armor

Email This Entry

Posted by Derek

Now here's a completely weird idea: a group in Korea has encapsulated individual living yeast cells in silica. They start out by coating the cells with some charged polymers that are known to serve as a good substrate for silication, and then expose the yeast to silicic acid solution. They end up with hard-shell yeast, sort of halfway to being a bizarre sort of diatom.
silica%20yeast.jpg
The encapsulated cells behave rather differently, as no doubt would we all under such conditions. After thirty days in the cold with no nutrients, the silica-coated yeast is at least three times more viable than wild-type cells (as determined by fluorescent staining). On the other hand, when exposed to a warm nutrient broth, the silica-coated yeast does not divide, as opposed to wild-type yeast, which of course takes off like a rocket under such conditions. They're still alive, but just sitting around - which makes you wonder what signals, exactly, are interrupting mitosis.
yeast%20cell.jpg
The authors tried the same trick on E. coli bacteria, but found that the initial polymer coating step killed them off. That's disappointing, but not surprising, given that disruption of the bacterial membrane with charged species is the mode of action of several broad-spectrum antibiotics.

"Hmmm. . .so what?" might be one reaction to this work. But stop and think about it for a minute. This provides a new means to an biological/inorganic interface, a way to stich cell biology and chemical nanotechnology together. If you can layer yeast cells with silica and they survive (and are, in fact, fairly robust), you can imagine gaining more control over the process and extending it to other substances. A layer that could at least partially conduct electricity would be very interesting, as would layers with various-sized pores built into them. The surfaces could be further functionalized with all sorts of other molecules as well for more elaborate experiments. No, this could keep a lot of people busy for a long time, and I suspect it will.

Comments (15) + TrackBacks (0) | Category: Biological News


COMMENTS

1. gyges on October 28, 2009 12:12 PM writes...

I'd want to fix them to polymer beads and use them in continuous flow brewing. Sorta like calcium alginate capture of yeast cells but more controlled.

Permalink to Comment

2. ralphbon on October 28, 2009 1:52 PM writes...

Remind me not to bite into that bread before renewing my dental insurance.

Permalink to Comment

3. Brooks on October 28, 2009 2:24 PM writes...

Minor typo: after "warm nutrient broth", you've got a <i) rather than <i>, thus hiding the key "does not divide" part of that sentence.

Is the silica a sufficiently hard shell to prevent the yeast cells from changing shape? Or is this just sort of a crust of separate pebbles? If it's a non-deformable shell, I would sort of wonder if the yeast could divide even if it was trying to.

Permalink to Comment

4. Kismet on October 28, 2009 5:50 PM writes...

How does it survive? Do the necessary nutrients diffuse through the silica shell? Doesn't sound very healthy for cells that depend on endo- or phagocytosis, does it? (i.e. all human cells?!)

@Brooks, I'm sure they tested whether it even *tried* to divide (e.g. looking whether the spindle formed).
But I am not sure if Derek is saying that the cells can't finish mitosis or if they don't even try (e.g. staying in G0 phase).

Permalink to Comment

5. Iulian on October 28, 2009 6:40 PM writes...

Hmmm... reminds me of an old idea I had: Injecting yeast into the blood stream, after a modification of some sort to stop it from dividing and to stop the immune system from atacking it. This stuff does both those things. It would have a huge market in places like Scotland or Russia... drunk all the time, pay only once. The glucose comes from the blood, the CO2 leaves through the lungs - perfect!

Permalink to Comment

6. Some Other Guy on October 28, 2009 7:32 PM writes...

Iulian, you are out of your mind.

Permalink to Comment

7. joopie on October 28, 2009 8:14 PM writes...

hot dang them there cells shore is sumpin else cordin to my fine mine!

Permalink to Comment

8. Interesting on October 28, 2009 10:15 PM writes...

Pretty different idea from a biomaterials standpoint. Traditionally people just tried to show that cells can survive and proliferate in the presence of a material. If it can only be done with mammalian cells....

Permalink to Comment

9. Dave Eaton on October 28, 2009 11:37 PM writes...

My dreams of a protective exoskeleton are one step closer to reality. Now, how to give yeast superpowers?

Very neat science.

Permalink to Comment

10. Patrick on October 29, 2009 12:08 AM writes...

Internalizing the encapsulated yeast, not in the blood but in the peritoneal cavity might have possibilities. Not so much for ethanol but for essential nutrients and vitamins.

Encapsulated pig cells are under trial for dibetes treatment.
http://www.scoop.co.nz/stories/SC0910/S00016.htm

Permalink to Comment

11. Donough on October 29, 2009 8:23 AM writes...

Another interesting application could be in biofuel production.

Current cells die when the alcohol levels in the fermenter get too high. By coating the cells with a selective layer the alcohol could be rejected and the cell lifetime could be prolonged.

In otherwords a selecticity membrane could be used to choose what nutrients and toxins a cell sees. Selective membranes of silica are relatively easy constructs (at least at macro scale).

Permalink to Comment

12. Iulian on October 29, 2009 10:27 AM writes...

Getting a constant concentration of alcohol in the blood is sometimes useful (as in keeping alcoholics from twitching under anesthesia, which I have witnessed and which was solved via IV drip).
11: If it would reject something as small as ethanol, the membrane would probably be impenetrable for glucose
But the possible applications could be huge, provided the body doesn't reject the silica shell, being a foreign body and everything.

Permalink to Comment

13. willis on October 29, 2009 3:23 PM writes...

"No, this could keep a lot of people busy for a long time, and I suspect it will."

I sense a government grant in the offing.

Permalink to Comment

14. interesting on October 30, 2009 7:17 AM writes...

This idea sounds similar to the Belcher group's work with viruses:
http://belcher10.mit.edu/

Pretty cool stuff.

Permalink to Comment

15. The Nano Age on June 15, 2010 5:38 PM writes...

Diamond-coated cells will be next!...

Permalink to Comment

POST A COMMENT




Remember Me?



EMAIL THIS ENTRY TO A FRIEND

Email this entry to:

Your email address:

Message (optional):




RELATED ENTRIES
A Last Summer Day Off
The Early FDA
Drug Repurposing
The Smallest Drugs
Life Is Too Short For Some Journal Feeds
A New Look at Phenotypic Screening
Small Molecules - Really, Really Small
InterMune Bought