New Nanoparticle Cancer Therapy

quixote9 tips us to a BBC story on a promising new cancer therapy using targeted nanoparticles. From the article: "The researchers used the nanoparticles to zero in on the network of blood vessels that supply the tumors in mice with nutrients and oxygen... [They] developed a technique for amplifying [the nanoparticles'] homing ability by designing a multifunctional nanoparticle that binds to a protein structure found only in tumors and associated blood vessels... The tests showed that within hours of the injection, the artificial platelets began blocking the supply without harming normal tissues. The scientists believe the nanoparticles could also be used to carry drugs to the tumor."

Comments

don't give it what it wants.

[User 956]

The scientists believe the nanoparticles could also be used to carry drugs to the tumor.

I believe in a twelve-step program, they call that being an "enabler".

Stand in awe

[mulhollandj]

Sometimes I look at how things like this work and I am just amazed and somewhat grateful to be living in an age with such incredible technology.

Re:Stand in awe

[Fred_A]

Sometimes I look at how things like this work and I am just amazed and somewhat grateful to be living in an age with such incredible technology.

Yes, if you're a mouse you can get cured of pretty much anything nowadays...

Halfway there, maybe

[Lurker2288]

I wonder what happens when the tumor is gone and a tiny little lump of clustered nanoparticles is free to float around on its own. Stroke, anybody? I'm not a doctor, but they're probably going to need to find a way to dissolve these artificial clots when they finish with the therapy, or they'll cause all sorts of circulatory problems.

Re:Halfway there, maybe

[spun]

I wonder what happens when the tumor is gone and a tiny little lump of clustered nanoparticles is free to float around on its own.

We send in even tinier, deadlier non-particles to destroy the clumps. I can imagine some of you wondering, "Isn't that a bit short sighted?" Well, then we just release wave after wave of chinese needle nanoparticles. Some negative nellies will no doubt complain, "Isn't that even worse?" But we're prepared for that! We've lined up a fabulous new 'gorilla' nanoparticle that thrives on needles. "But then we're stuck with gorillas?" I can hear you asking. That's the beautiful part, when winter rolls around the gorillas just freeze to death.

Re:Halfway there, maybe

[Dan Slotman]

You probably end up pissing them out or something equally boring. As far as unbound particles go, if they stay in your bloodstream forever, that would be a good thing. No new tumors.

Re:Halfway there, maybe

[milamber3]

I'm not sure how long it takes to kill the cancer by blocking its blood supply but I work with nanoparticles in my lab and the ones we create are biodegradable and can be made to last for varying amounts of time (~1-7 days normally) based on the material. I suppose they could greatly decrease the chance of problems post-cancer if they formulate the clot to degrade after average amount of time needed to starve the cancer.

Re:Halfway there, maybe

[sytonit]

I'm a chemist that does drug formulations and I have made nanoparticles. The nanoparticles that I made were specifically, solid lipid nanoparticles (SLNs) for an oral formulation to increase bioavailability, but we have also made nanoparticles out of biodegradable polymers. The solid lipid nanoparticles dissolve quickly because of the low melting point of the lipids. The biodegradable polymers are typically poly lactic glycolic acid (PLG), which because of the large surface area of nanoparitcles should cause more rapid hydrolysis of the polymer to it's monomer, Lactic acid or Glycolic acid. Lactic acid is what is produced in your muscles after you work out to cause you to be sore, but both Lactic and Glycolic acid are commonly found in the body.

Nanoparticles are really small so it would take a lot of them to cause a clot. The larger microparticles when they are injected form a depot and are not intended to be in the circulatory system.

I remember hearing something about this technology but I think that there were serious side effects to the "homing ability" of the nanoparticle. I'm assuming that the nanoparticle is a biodegradable polymer with some sort of protein coating.

BRRRRRAIIIIIINNNNNSSSSS!!!!!

[The evil doctor Matt]

"the supply without harming normal tissues", however test subjects did develop a taste for human flesh and could only be stopped by a bullet or sharp blow to the head...

When

[Swimport]

Every few months there is a cancer break through it seems. When are we finally going to see something in the hospitals? Is it the FDA and bureaucratic red tape, are these vapor cures? If its red tape, why not bring your drug down to Mexico, I'm sure plenty of cancer patients wont mind crossing the boarder for something that works. And if they every do cure cancer, invest all your money in Philip Morris.

Re:When

[Hijacked Public]

It would certainly seem like cancer has been cured many times over, particularly if you get your medical news from Slashdot, where there is both a tendency to react to mostly theoretical research as if it would be available on the shelf tomorrow and a strong desire to place on the front page any article with any mention at all of nanoparticles, or nanobots, or nanos in general.

Re:When

[Otter]

I remember being somewhat excited about a headline like that a few years ago but nothing ever comes of these breakthroughs.

Two things:

1) As someone else points out, it's relatively easy to kill cancer cells in a dish (see the last "Cure For Cancer!" story from a few days ago) or even in a mouse (as in this case). That's a long, long way from a usable treatment.

2) In fact, some fraction of these do become useful treatments, but you're not aware of them because they're not miracle cure-alls and because they're not advertised on television like Cialis or Clarinex.

Re:When

[Poruchik]

And some DO become useful, 100% cures (or preventive vaccines: http://en.wikipedia.org/wiki/HPV_vaccine)

Re:When

[Swimport]

I will admit its definitely possible that a company would rather treat someone at high cost for the rest of their life than cure them. However if they had the cure for cancer they could charge whatever they want for it. $250,000 $500,000 who knows. Also if a company was sitting on the cure for cancer, who knows, maybe a noble scientist would leak it.

Re:When

[Swimport]

Would you like to be the one who signs off on offering patients with terminal cancer a treatment that could potentially harm their health? Hmmm?

As long as they knew the risks ahead of time, yes I would. If there is a treatment that might help, but also may hurt someone who is going to die from cancer anyway, who is anyone to keep that treatment from them should they decide they want to take the risk??

Or even better:

[spun]

When asked for comment on the story, the Governor of California said, "It's not a toomah!" Later, he issued a retraction, adding, "If it bleeds, we can kill it!"

Hope

[simonharvey]

Although I think that this is a great idea with alot of good potential however I cannot seriously see this coming into fruition due to the IP, testing and marketing that has to be done.

I do hope that something good comes out of it. But it is that you hear about little break throughs like these all of the time and nothing seems to come from them due to the massive hurdles that keep coming up.

Kind Regards
Simon Harvey

Re:why we are not further along...

[Poruchik]

This is utterly irrelevant. And wrong-headed. My grandfather has cancer (lymphoma), but none of my relatives has had a heart attack. Does it mean I should go rant to stop all cardio related research in favor of cancer research? Any and all research (the usual caveats apply) is good thing.

Mathematical and Computational Modeling

[macklin01]

Some of my colleagues (e.g., Vittorio Cristini) have been modeling the potential benefits of nanoparticle drug delivery for a couple of years now. As has been known for some time (e.g., see papers from R.K. Jain), the blood vessels that grow to supply tumors with nutrients (the tumor-induced neo-vasculature) are different than regular, non-pathological vessels. They tend to be more tortuous and leaky, with larger holes than regular vessels.

This is where the nanoparticles come in: one can design nanoparticles that encapsulate cancer drugs in particles that are too large to exit normal blood vessels but can pass through the leakier, tumor-induced blood vessels. This naturally targets cancerous tissues.

However, there are other issues to consider. Due to the high pressure inside tumors (due to the rapid proliferation of cells within a confined area, among other factors), along with the leaky vessels, blood flow can be very poor inside a tumor, and so while the drug may be targeted toward and delivered to the tumor, it may not actually penetrate very far into the tumor. Some great work has been done by Steven McDougall, Sandy Anderson, and Mark Chaplain in this area. In particular, look at their DATIA (dynamic adaptive tumour-induced angiogenesis) papers.

One way around this (suggested by R.K. Jain and Vittorio Cristini, among others) is to use targeted anti-angiogenic therapy to prune out the worse blood vessels and improve flow within the tumors, thereby also improving drug delivery and penetration.

Lastly, on the therapeutic aspect of blocking up tumor blood vessels with the nanoparticles, the work we've done (see this paper, which will appear in the Journal of Theoretical Biology soon), indiscriminately cutting off the nutrient supply to a tumor can increase tumor invasiveness by increasing morphological (shape) instability. (See some of the animations here.) So ironically, while more tumor cells may be killed, those that remain may spread farther and initiate new tumors. Given that hypoxic tumor cells are more likely to be resilient to further treatment (e.g., hypoxic breast cancer cells), this is a problem worth keeping in mind when planning anti-angiogenic therapy.

If you're interested in these topics, please do check out the paper above. (You can also download it at my website without any special memberships.) Even if you don't like it, we have a lot of references you may find handy. -- Paul

Basic Stuff

[Doc Ruby]

What about just some generic artificial platelets that clot bloody wounds like the natural platelets? Platelets are by far the most short-supplied blood product that constrains blood products. Every serious trauma patient who gets into a hospital quickly exhausts their own platelets, and consumes easily a half-dozen donors, usually triple or more the amount of red blood cells they consume.

Anticancer targeted platelets are a great advance. But many times as many people need the simpler generic stuff. Before pharmacos get paid lots of public money for the anticancer platelets they'll surely patent for maximum profit (after heavily subsidized and risk-mitigated development), they should produce the generic platelets that aren't as profitable, but help save many more people.

"Nano" vs. "Drug"?

[chub_mackerel]

I admit to a large amount of cluelessness in this area, so can someone enlighten me on a semantic distinction?

I know that all things "nano" are hot right now, but if this had been invented 15 years ago, would it just have been called a "drug"? In other words, is this simply an engineered molecule or substance or whatever that binds to specific receptors in certain ways for certain effects... what makes it "nano" other than its size? If that's the only criteria, then why aren't ALL drugs "nanoparticles"? Are these particles bigger or produced in a different way?

I'm just confused - when I first heard of nanotechnology I imagined little machines. That may be a misconception on my part, but I still feel that simply being a little grain of something (even if that something was engineered to have useful properties) doesn't quite seem to warrant the designation.

target cancer stem cells too maybe?

[theshowmecanuck]

I was thinking about the last big cancer breakthrough that said doctors were targeting the wrong thing when trying to fight cancer for the last however many decades. They try to kill the tumour but leave the cancer stem cells that perpetuate the disease. That's why when they remove the tumour, the cancer just eventually grows back. If they can target the cancer stem cells with the nano-particles that would be cool. Get rid of the the symptoms and the disease.

Re:Rather funny, isn't it?

[orcrist]

Geeks talk about the importance of people, but anything involving Microsoft will have 500+ comments in 5 minutes, and anything involving science will have barely 100+ in an hour.

Perhaps there are a bunch of lurkers who -- like me -- don't feel qualified to comment on such a highly technical subject outside their field or experience. I'm certainly interested in this subject and what people have to say about it, but I'm not likely to be able to throw in a point of fact like I might in a Linux vs. MS flamewar, or a politics debate. It would be interesting to know the number of views stories and their comments get -- maybe that's already possible? I'm too lazy to check right now. In any case, it would reflect the level of interest in the story better than the number of comments.

BTW I also found your comment an enlightening and interesting contribution to the discussion. I would have modded it as such but I decided to reply instead :-P

-chris