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Cancer cells, covered in bees!
September 29, 2009 9:28 AM   Subscribe

Nanobees! (trained to kill cancer cells)

A nanoparticle carries melittin -- a toxic peptide found in bee venom that does not produce allergic reactions -- throughout the body. The ligand (chemical that binds two compounds, in this case the nanoparticle and the melittin) has an affinity for attaching to a receptor plentiful in newly formed blood vessels, which are plentiful around tumors. Plus, it kills the cells via apoptosis (natural cell death), not necrosis, which should reduce side effects. So far only animal studies. The scientific paper itself. Another take on it.
posted by msalt (29 comments total) 5 users marked this as a favorite

 
Bees?
posted by Optimus Chyme at 9:36 AM on September 29, 2009


Hey, my bees!
posted by nanojath at 9:40 AM on September 29, 2009 [3 favorites]


Exciting, but a long way off. With no idea how the particles interact with healthy blood cells, much less your liver, this has a ways to go.

Still, I know someone who's getting a sizable research endowment under the xmas tree.
posted by lumpenprole at 9:41 AM on September 29, 2009 [1 favorite]


Bees?

Nano-beads!
posted by Pope Guilty at 9:44 AM on September 29, 2009


The best part? Sweet, delicious nano-cancer-honey.
posted by boo_radley at 9:50 AM on September 29, 2009 [3 favorites]


Lesse...do I make the joke about firing this from the mouth of a dog that barks bees when it barks, or do I make the joke about how Bernard, I ate your bees?

Tough choices.
posted by Jilder at 9:51 AM on September 29, 2009


I work for Kereos, the biotech startup that is licensed to develop the technology, though I don't speak for the company, of course.
posted by jedicus at 9:55 AM on September 29, 2009


BEEEEEEEEEEEEEEES
posted by Inspector.Gadget at 9:56 AM on September 29, 2009


Wu-Tang nanobees... they're on a swarm!
posted by Joe Beese at 9:57 AM on September 29, 2009 [3 favorites]


Peak 37.
posted by mrgroweler at 10:02 AM on September 29, 2009


Is it me or are the currently-active threads all highly silly this morning?

It's like they replaced the login cookie with login psilocybin.
posted by Pope Guilty at 10:03 AM on September 29, 2009


I hope the treatment is administered like this.
posted by Turkey Glue at 10:03 AM on September 29, 2009


HEY GUYS THE BEES TOLD ME TO TELL YOU THAT THEY'LL LET YOU HAVE THE VENOM IF YOU PLANT SUNFLOWERS LIKE EVERYWHERE.
posted by The Whelk at 10:05 AM on September 29, 2009


Exciting, but a long way off.

True enough. On the other hand, the approach is not limited to bee venom. They're already looking at using it to deliver existing chemotherapy drugs specifically to cancer cells, drastically reducing the toxicity. And it's still beeutiful:

"In effect, we've got something that does what a bee does except it's a synthetic particle. It's got a stinger and injector to insert the toxin into a cell," says Samuel Wickline, a professor at Washington University's medical school.

On the third hand, if they escape into the wild and mutate, they could really ruin some barbecues.
posted by msalt at 10:08 AM on September 29, 2009


OH NO! NOT THE BEES! NOT THE BEES! AHHHHH!
posted by lumensimus at 10:08 AM on September 29, 2009


Got nothing on Carcinoma Angels.

Except for that one side effect...
posted by Kirth Gerson at 10:08 AM on September 29, 2009


Is the bee venom part the news here? I mean scientists (and by scientists I mean anyone who stops to think about it for a moment) know of all kinds of things that will kill cancer cells but will also kill normal cells. I mean hell, if it weren't for that pesky issue of targeting, you could cure cancer with a can of hair spray and a zippo lighter.

Rather than look for a drug that stays on your nanoparticle until you're ready for it to fall off (which feels like a middle step in many of Rube Goldburg's famous devices), why not make your particles, bind them good and hard to their targeting component (I'm guessing the business end of an antibody) and also to your drug with something less sturdy. Something that you just happen to have an enzyme to cleave that will not, itself, interfere with anything vitally important your patient is doing.

Inject the nanoparticles, let them find their target, then once they're where you want them, inject the de-linking enzyme. (Your countless hours of finding exactly the right enzyme and linker to give you useful pharmacokinetics go here.)
posted by Kid Charlemagne at 10:16 AM on September 29, 2009 [3 favorites]


I mean hell, if it weren't for that pesky issue of targeting, you could cure cancer with a can of hair spray and a zippo lighter.


*Runs out to patent Aquanet-Zippo chemotherapy...*

I'll make billion$!
posted by darkstar at 10:47 AM on September 29, 2009


Is the bee venom part the news here?

No, not as such. The nanobees angle is just a bit of shtick the media has latched onto. The real news is the use of melittin in combination with the targeted nanoparticles. The same targeted nanoparticles are being investigated for imaging, atherosclerosis treatment, and other anti-cancer uses (e.g., in combination with other anti-cancer agents).

Inject the nanoparticles, let them find their target, then once they're where you want them, inject the de-linking enzyme.

Some work is being done by the same scientists on "inject the nanoparticles, let them find their target, then once they're where you want them, shake the drug loose with ultrasound." Not quite the same as cleaving the linker with an enzyme, but it accomplishes much the same result.
posted by jedicus at 10:57 AM on September 29, 2009


Ring ring ring ring ring ring ring, the nano-bees!
posted by zippy at 11:38 AM on September 29, 2009 [2 favorites]


The ligand (chemical that binds two compounds, in this case the nanoparticle and the melittin) has an affinity for attaching to a receptor plentiful in newly formed blood vessels, which are plentiful around tumors.

This description appears to be a little muddled... A ligand is a substance that binds to a receptor, not to two compounds. In this case, both the ligand (a peptide) and the mellitin are incorporated into the surface of the nanoparticle; they don't interact directly.
posted by monocyte at 12:01 PM on September 29, 2009


" ... login psilocybin" — Yes, please. I would, however, trade it for a five year moratorium on nano- things. My hand, it is made of nano-particles!
posted by adipocere at 12:17 PM on September 29, 2009


Everyone loves nanobees and hates cancer, but let's how much pro-bee feeling we have when science unleashes the megabees and mechamegabees, which are designed to aid in planetary exploration but unexpectedly seem to emit pulses of radiation to each other that are not yet fully understood but are probably not a big deal.
posted by ignignokt at 12:21 PM on September 29, 2009 [3 favorites]


I, for one, welcome our new cancer-fighting nanobee overlords.
posted by mek at 12:47 PM on September 29, 2009


Are they making microhoney? Delicious, delicious microhoney.

Support bee industry!
posted by JHarris at 12:56 PM on September 29, 2009 [1 favorite]


That's no human bee...
posted by wildcrdj at 1:16 PM on September 29, 2009


... login psilocybin

Man, you should see what you get when you post a question to AskMe. I don't know what it was, but I was like seeing ..dancing pumpkin men and shit. Heady.
posted by The Whelk at 3:28 PM on September 29, 2009 [1 favorite]


So the targeted particle is the news. Does anybody know how specific this is to the new blood vessels? Like, who is looking at this for delivery of kidney medication? (My son has minimal change disease, but has a very bad reaction to steroids - if you could just target the steroids to the kidneys and not affect the rest of the person, this would be an incredible step forward.)

This will be the next big wave of medicine, the one that makes people in 2025 say, "It was like a Goddamn Spanish Inquisition."
posted by Michael Roberts at 6:32 PM on September 29, 2009


Well, according to monocyte, I already butchered the description of the ligand situation (and with that login name, who am I to disagree? I was just summarizing the WSJ article), but I believe this is at least one section of the original paper that addresses both your question and the ligand issue:

we sought to determine whether specific molecular targeting of the nanoparticles to neovascular targets would be useful in treating nascent early-stage tumors or precancerous lesions that are just entering an aggressive angiogenic phase. ...Human melanoma (C32) cells that express the αvβ3 integrin were used in vitro to assess the interactions of targeted nanoparticles with cell membranes by surface plasmon resonance. Nanoparticles were targeted by incorporating a peptidomimetic αvβ3 integrin–binding ligand (a highly specific vitronectin antagonist at 200 copies per nanoparticle) as previously described (34–36). ... To confirm the therapeutic activity of the targeted melittin-loaded nanoparticles against potential tissue targets, the proliferation of mouse endothelial (2F2B) cells and human melanoma (C32) cells in culture was tested. ... \

By including αvβ3 integrin mimetic on the nanoparticles, the interaction of nanoparticles with cells was increased 4-fold. This increase in cell nanoparticle interaction resulted in a reduction of the IC50 for inhibition of cell proliferation to 6.8 ± 2.14 μM for C32 cells and 8.39 ± 2.35 for 2F2B cells. Thus, the increased binding of the nanoparticles to the cells accounts for the increased activity of the targeted nanoparticles. ... The activity of the targeted melittin-loaded nanoparticle complex closely approximates the lytic activity of free melittin but now is restricted to the cancer and endothelial cells that express the integrin. ...

An interesting and unique form of interaction between the nanoparticles and the targeted cells became apparent through these studies. Transmission electron microscopy (TEM) was used to confirm the role of the receptor-ligand targeting to enhance interactions of αvβ3 integrin–targeted nanoparticles with cells. In the absence of the targeting peptidomimetic, very few nanoparticles were associated with the surface membrane of the cells (Figure 4C). However, when the targeted nanoparticles were presented to the cells, large numbers were associated with microvilli and also extended to the membrane surface (Figure 4D). Yet no evidence of direct cellular membrane disruption or endocytosis of particles was observed even in the presence of melittin.

posted by msalt at 10:29 AM on September 30, 2009


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