backtop


Print 28 comment(s) - last by William Gaatje.. on Jul 25 at 3:20 PM


Within a minute the drugs, using the new nanoparticle delivery system, are already clustering at tumor sites.  (Source: Case Western Reserve University)
New technology using gold nanoparticles attacks tumors faster, more aggressively

While developing new cancer killers is an important priority, half the difficulty in winning the battle against cancer is just getting the drugs to the tumor itself.  The concept of drug delivery is an important one as current blood borne chemotherapy treatments take two or more days to reach the tumor fully. 

Lots of exotic methods have been devised to cut drug delivery time, but one of the more promising ones comes from a new breakthrough from researchers at Case Western Reserve University.  The researchers successfully tested a new delivery system, which brought cancer drugs to tumors in lab mice within a couple hours of their injection.

To accomplish this ultra-speedy delivery, researchers used gold nanoparticle vectors to deliver photodynamic therapy (PDT) drugs, a class of drugs that burn away cancer with light via wavelength energization, to tumors.  Case Western Reserve University graduate student Yu Cheng, one of the paper's coauthors explains, "Gold nanoparticles are usually not used for the PDT drug vector.  However, gold is chemically inert and nontoxic."

PDT drugs, which are seeing increasing use due to their efficacy, are typically difficult to use properly.  In order to prevent the drugs from being prematurely activated, the patient must stay in dim light for days until the drugs reach the tumor.  With the new method, the drugs become much more useful, as the inconvenience is lessened to a mere couple of hours.

Paper co-author Clemens Burda, associate professor of chemistry and director of the Center for Chemical Dynamics and Nanomaterials Research at Case Western Reserve University states, "By shortening the waiting time from drug injection to activation, PDT patients are much less inconvenienced and tend to have a more normal lifestyle."

The new delivery device consists of a gold nanoparticle (Au NP) at its core.  Gold nanoparticles are selected due to their low toxicity, versatile surface chemistry, large surface-to-volume ratio, and variable size and shape.  The nanoparticle is then coated in fatty polyethylene glycol (PEG) ligands, which make it resemble a hairy ball.  The coated molecule does not react with proteins and is fat and water soluble, making sure it reaches the tumor intact. 

A photodynamic chemotherapy drug (Pc 4) is inserted between each of the PEG ligands, coating the ball with cancer drugs.  This particular drug was developed by Case Western Reserve's Malcolm Kenney, professor of chemistry.  The combined nanoparticle gravitates towards tumors within hours, thanks to much faster dispersion.  When it reaches the site, scientists use focused red light to excite the PDTs and fry the tumor. 

A small 1/4-mL injection holds 100 million Au NPs each with 100 PDT drug molecules hitching a ride.  The researchers hope to adapt the coated Au NP system to a broad variety of bloodstream drugs to speed treatment.

In test on mice, the drug was injected in the mice's tails and within in minutes the drug was gravitating around tumors in the mice's bodies.  Human trials, following the successful mouse trials have not yet been planned.  The Food and Drug Administration (FDA) will have to approve the combined particle.  This may be coming soon, though as the components -- Au Nps, PEG ligands and Pc 4 -- are all FDA approved.

The researchers hope to focus their future efforts on modifying the PEG "hair" ligands" for speed and specificity.  Also, they hope to optimize and minimize drug and material load for a finished treatment.  Professor Burda says the beauty of the technology is that such adaptations and optimization can easily be made.

Says Professor Burda, "The system is very modular.  We can change the size and shape of the Au core NPs and we can change the functionality of the PEG ligands. This should lead to optimization of the drug targeting and therapy. If our research is successful, other researchers might adapt this drug delivery system to other diseases and applications."

The team's findings are reported in a paper in the current issue of the Journal of the American Chemical Society.

The research was funded by the National Science Foundation, National Institute of Health/National Cancer Institute and the Biomedical Research Technology Transfer Center.





Comments     Threshold


This article is over a month old, voting and posting comments is disabled

i've heard this before
By jlips6 on 7/23/2008 2:34:52 PM , Rating: 2
I recall an earlier article talking about using these gold nanoparticles to latch on to cancerous cells and kill them by frying the cells with radio waves. Is this just a different use of the same technology?




RE: i've heard this before
By TheDoc9 on 7/23/2008 2:55:42 PM , Rating: 2
I'm still waiting for the other shoe do drop on these nano-particles. Probably nothing really bad will happen but suppose some of them get stuck in the persons brain, or perhaps lodged in liver and kidney tissue, what then?

These exotic treatments are great but in addition people should also be educated on proper diet and lifestyle throughout every year of school.


RE: i've heard this before
By Regs on 7/23/2008 3:06:08 PM , Rating: 2
Diet? I don't want my kid growing up deprived of everything however I sure hell don't want him growing up to be obese and unhealthy.

I still blame most cancer on DNA make-up and genetics. Just to put things in perspective, mo point growing up without treating yourself to the "fine" things in life, only to die in a car crash as a young adult.

Any progress in treating cancer patients with medicine is good news to me!


RE: i've heard this before
By omnicronx on 7/23/2008 4:09:42 PM , Rating: 2
quote:
I still blame most cancer on DNA make-up and genetics.
You keep on believing that. It has been well documented that Cancer is more common in overweight people. The evidence on weight is strongest for post-menopausal breast cancer and cancer of the endometrium , gall bladder and kidney.

Basically it could go two ways, the more likely scenario is that obesity in one way or another makes it more likely for someone to have cancer. OR the very unlikely scenario that obese people have been passing down cancerous genes for generations that non obese people are less likely to have.


RE: i've heard this before
By oab on 7/23/2008 5:19:15 PM , Rating: 2
Or, some people through various genetic things are more vulnerable to cancer causing things in the air and water.

The genes don't CAUSE them to get it, they are just more vulnerable IF exposed. (ie. expose a bunch of fruit flies to radiation and at xxx dosage some will die, but other will survive and reproduce).


RE: i've heard this before
By William Gaatjes on 7/23/2008 5:54:13 PM , Rating: 2
Don't forget viruses. They are very common and we are infected all the time. But since our bodies are always maintaining themselves we don't really notice it until we get a nasty one.

You can see it for example with people who have no immune system. Bacteria, fungee and viruses are creating havoc.

Viruses are a lot more common then on would think.

But i am curious about 1 thing that i do not understand...
Tumors usually need a lot of blood to keep on growing.
Are these drugs depending on the fact that tumors need large amounts of blood and therefore the chance that these drugs will end up in the tumor is big ?
Because i would think that our brain likes a lot of blood too.

What am i not seeing here ?


RE: i've heard this before
By William Gaatjes on 7/23/2008 6:11:44 PM , Rating: 2
I agree with Omnicronx, it is true. Cancer is quite common.

I once read an article that fat tissue is a perfect storage for unhealthy chemicals. Chemicals that can cause cancer direct or indirect.

I think for example of dioxines in cowmilk and fatty tissue from cows. The dioxines accumulate inside fatty tissue.

Most people think fat is bad, but we need a healthy amount of fat(or lipids) to transport chemicals(We depend on but do not want floating freely in our blood.) through our bodies.

The more fat you have, the bigger the chance is you have a lot of dangerous chemicals inside you.

Also our blood is pumped around because of our hart.
But our lymphatic system depends on active movement of skeletal muscles for the fluids to be moved around. These fluids are filled with contaminated immune cells. Some of these cells can carry cancer cells. If you do not move much, which is usually the case with obese people your lymphatic system can fail to do it's work properly.
Therefore increasing the chance of cancer.

This is one reason why people start to feel more well when they sport, their lymphatic system is cleaned up.

If you connect the dots it is all quite simple.


RE: i've heard this before
By tmouse on 7/24/2008 9:02:26 AM , Rating: 2
Ok I would like to clarify a few points; first this is not an improved targeting system it is an improved delivery system. The differences may seem subtle but are important. The targeting in these experiments is purely random, as should be evident by the enormous fluorescent region not included in the circled tumor. This method also accumulates the photoreactive agent in the lungs and kidneys. The important part is not the gold nanoparticles (which I suppose if far sexier than the real important component good old polyethylene Glycol). Most nanoparticles have very fast delivery times the 2 day versus 2 hour time reduction is comparing the nanoparticle conjugate to the free photoreactive compound which is not very soluble in water. There is no data suggesting the gold nanoparticle is any more efficient than any other, although it is biologically inert.

In response to a few posts by William Gaatjes viruses are a large factor in cancers of certain animal species but are minimal at best in human cancers for reasons currently unknown. There is no doubt a healthy lifestyle is the best insurance, the immune system probably eliminates over 99% of mutant cells (ok that number was pulled from my anal orifice but it is a very high albeit it unknown percentage). Of course it will not guarantee it if you were dealt a bad hand in the genetic poker game. In regards to nurture versus nature for the majority of cancers is sort of a chicken and egg situation. There are causative links between certain mutations and cancer and strong links between cancer susceptibility and existing alleles in the human genome. In the case of mutation it affects the machinery directly, now the mutation itself can be due to random errors in replication or correction, or it can be caused by outside agents like free radicals. The same with the alleles which increase susceptibility, if the trigger event does not happen, no cancer. You and omnicronx are right about the correlations of fat content and increased cancer risks. Fat can have several mechanisms; first lipid peroxidation can form free radical formation which in turn plays havoc with DNA, and many organic compounds especially heterocyclic compounds are fat soluble allowing for retention and biomagnifications, the breakdown of these compounds results in reactive intermediates which can start the genetic cascade toward cancer.


RE: i've heard this before
By Jaybus on 7/24/2008 10:12:27 AM , Rating: 2
Yes. There is a big difference between targeting and delivery. The targeting, in this case, is essentially the targeting of the light used to activate the PDT agent. I assume they use a red laser and target by focusing. That may well be looked upon as better targeting, however, since damage to normal cells in the area should be far less than that caused by systemic use of chemotherapy agents (or radiation treatment for that matter). That assumes, of course, that the NP/PDT agent is itself relatively non-toxic.

There is a new drug, PV-10, currently in phase 2 trials that apparently works by truly targeting cancer cells. See http://www.clinicaltrials.gov/ct/show/NCT00521053. It is currently in phase 2 trials for melanoma, but apparently could potentially be used on other solid tumors. The results from the phase 1 study were astounding.


RE: i've heard this before
By tmouse on 7/24/2008 1:20:21 PM , Rating: 2
Err no; The light is not the targeting mechanism, it is the trigger. In this case the targeting mechanism is the fact that tumors have "leaky" arterial systems that can allow more of the vehicle to penetrate and become available for absorption through the cell membrane. That’s it. There is nothing tumor specific, it is somewhat more specific than general chemo but not by much. It IS better for this payload since the photoreactive agent is usually not very soluble in water.

In the study you linked to the targeting mechanism is a catheter, it is an Intralesional injection for chemoablation using 10% rose bengal disodium; unless you had the wrong link. There isn’t any specific frequency of energy that is tumor specific.


RE: i've heard this before
By tmouse on 7/25/2008 7:41:09 AM , Rating: 2
Having given your reply additional thought I see where you consider the laser the targeting system, ie zapping the tumor and trying to avoid other tissues that may also have taken up the photoreactive payload. That is more specific than the current systemic toxin chemo and so could be considered a plus. The difference is in magnitude, I feel delivering payloads to nonspecific tissues is still a poor mechanism. This procedure requires vascularization so the probability of malignant metastasis is vastly increased. Killing the main tumor but being unable to target metastases is, in my opinion, poorer than the systemic approach. An ideal targeting system would recognize the tumor cells thus targeting the primary and potential secondaries. The problem is we have been looking for decades and only found a handful of tumor types that have targets. Most tumors are barely different (on their surfaces) from normal, probably because our exceptionally efficient immune systems destroy the more divergent cells before they can even form tumors. So my point is if a payload was taken up by lets say brain tissue, you could not use a laser to kill the primary in the brain where general chemo would work since neural tissue is not mitotically active (I’m vastly oversimplifying the problem i.e. blood/brain barrier ect.)


RE: i've heard this before
By William Gaatjes on 7/25/2008 3:20:01 PM , Rating: 2
It's not that easy to track viruses in a healthy human being.

I know there is a link between cancer in the cervix or uterus of women and sexual transmitted virus named human papilloma virus - HPV.

And there is research done where they found oncorna viruses in brain tumors.

I am sure when the research equipment improve more they will find more leads.


RE: i've heard this before
By Moishe on 7/23/2008 3:11:08 PM , Rating: 2
Maybe cancer patients will now get mugged for their blinged out gold particles. I'm sure if we add the word "nano" and add white earbuds, the muggings will go up.


If I ever had cancer...
By Amiga500 on 7/23/2008 3:05:28 PM , Rating: 3
Could I not allow doctors to try a experimental method on me?

I'd much rather have that than rot slowly.

Or do these guys have a veto?

The Food and Drug Administration (FDA) will have to approve the combined particle.

It might be a good way to speed up research, as scientists would get much more information, much quicker than current - I reckon most people would have a similar outlook on it as me when faced with death.




RE: If I ever had cancer...
By Master Kenobi (blog) on 7/23/2008 3:34:37 PM , Rating: 5
If I'm terminally ill and they want to try some crazy stuff on me that may or may not work, go right ahead. I'm dead anyways, might as well get some solid research results done before I kick over.


RE: If I ever had cancer...
By Fnoob on 7/24/2008 8:30:51 AM , Rating: 2
When you kick over will you turn into a pile of robes? Or will we have to construct a funeral pyre? Either way, any cancer that dare strike you down will only make you more powerful than we could possibly imagine!


RE: If I ever had cancer...
By Sulphademus on 7/23/2008 4:09:54 PM , Rating: 2
If youre over 18 (in the USA) and of sound mind, then they have to get your approval to do anything. If youre unconcious or something then the decision goes to your next of kin (husband/wife, parents, siblings, children). Being that its fairly unlikely that you will be recieving cancer treatment while in a coma, the only way you will get an experimental treatment without your consent is with an extremely unethical doctor.


RE: If I ever had cancer...
By 67STANG on 7/23/2008 7:05:56 PM , Rating: 2
You could also go out of the US to get this done. There are other countries currently experimenting with these nano-treatments, with little or no restriction on "test subjects".


RE: If I ever had cancer...
By Fnoob on 7/24/2008 8:34:04 AM , Rating: 2
Hoping to become a test candidate in Europe in the next month or so. This sounds far more promising than my current options. :{


RE: If I ever had cancer...
By Sulphademus on 7/25/2008 8:49:17 AM , Rating: 2
quote:
Could I not allow doctors to try a experimental method on me?


To me it sounded like he DIDNT want this new method. Other commenters make it sound like he does, so I guess Im just confused on it.


RE: If I ever had cancer...
By tmouse on 7/25/2008 9:39:24 AM , Rating: 2
I can see where you were confused; it would have been clearer if he said "couldn’t I just allow doctors". From the rest of the post it is clear that he was wondering if he would have the choice or would the FDA be able to prevent use of the protocol. I'm old enough to remember an old Benny Hill skit where the actress says "What’s that in the road.....a HEAD!" he says cut (as a director) and tells the girl it "what’s that in the road ahead?" "God...it’s just a bleeding football."


RE: If I ever had cancer...
By tmouse on 7/24/2008 9:32:45 AM , Rating: 2
Ok I would like to address this, I worked at a large cancer hospital in my early years so I do know how many would volunteer for studies. Fast in science rarely equals good. The FDA and their counterparts do not veto therapies but have set mandatory mile stones for progress toward clinical treatments. While it may seem to some this hampers progress keep in mind patients of terminal diseases are the most vulnerable people you can know. They will grasp at anything and I mean anything, which is perfectly understandable. The VAST majority of these "studies abroad" are simply put scams. I cannot think of a single, proven therapy that has come from these studies. They never publish results, they barely keep records. In many of these cases it is felt "well they are dying anyways so why not give them some hope"? They do not give anything most have high price tags, the real motive is fleece them they are dead anyways and the host countries could care less. I have nothing against alternative therapies’ for the truly hopeless cases but it would be better in a controlled environment so their deaths are not a total waste to make some scam artist wealthy. If I seem harsh its because I have seen people who could be helped waste their chance on these crooks and then come back too late. Getting back on track; many people are simply not suitable for studies. When there has been a shortage of patients for a cohort study it is because you want as little confounders as possible. These studies do not have untreated controls like animal studies as that would be unethical. Very sick people can die using therapies that can save less sick patients. High mortality will result in the closure of a protocol. It is good science to work down not up to minimize acceleration of patient morbidly and mortality and maximize exposing areas of improvement from a scientific standpoint. I understand when the public states things like allow the terminally ill to be used or prisoners ect. Please keep in mind the researchers are people too, even if someone is going to die "anyways" it is cold comfort to accelerate this for little return. The current system DOES work. Just my perspective.


Dumb question
By DeepBlue1975 on 7/23/2008 3:55:42 PM , Rating: 2
quote:
The new delivery device consists of a gold nanoparticle (Au NP) at its core. Gold nanoparticles are selected due to their low toxicity, versatile surface chemistry, large surface-to-volume ratio, and variable size and shape. The nanoparticle is then coated in fatty polyethylene glycol (PEG) ligands, which make it resemble a hairy ball. The coated molecule does not react with proteins and is fat and water soluble , making sure it reaches the tumor intact.


When you say soluble, shouldn't it be insoluble?
I can't make sense of it otherwise.
If what I'm saying is wrong, could someone care to explain it a bit further?




RE: Dumb question
By tmouse on 7/24/2008 9:42:04 AM , Rating: 2
I like to tell my students there are no dumb questions, just unanswered ones. The compound itself is very insoluble in water so it takes high doses and longer times for absorption. You want it fat soluble to be absorbed into the cells, and water soluble to be carried by the blood. The nanoparticle is small and is just an inert base. The PEG coating allows the material to be water soluble and protects the particle from serum protein binding which will lead to clearance.


What's next?
By deeznuts on 7/23/2008 3:15:06 PM , Rating: 3
What's next, nanomachines?




nice to see
By marvdmartian on 7/23/2008 4:27:10 PM , Rating: 2
Nice to see that they're making progress, of sorts. Having watched my father's 3.5 year fight with lung cancer, and what he went through every time he took chemo treatments (that currently attack much more than the tumor), any improvement on the treatments will be much welcome!

quote:
However, gold is chemically inert and nontoxic.

Well, yeah, in this small of an amount. However, gold can cause heavy metal poisoning problems, in sufficient amounts. My sister has rheumatoid arthritis, and took gold injections for a few years, and they were quite effective. However, she had to stop, due to the heavy metal problems she might have had, if they'd continued using that treatment. :(




Pretty damn sad...
By JonnyDough on 7/24/2008 4:20:49 AM , Rating: 2
when we're forced to troll because the people posting articles can't even spell "targeting." Why should we edit your garbage?




When?
By SiliconAddict on 7/23/2008 9:42:57 PM , Rating: 1
This shit ALWAYS annoys the hell out of me. They announce this crap....which won't be available for 5+ years. Meanwhile a friend of mine has to go through regular treatment for a rather aggressive form of breast cancer.
I understand the roll of the FDA....I also want to slap the shit out of them sometimes for how long it takes. there should be multiple tracks\forks for such innovations.

Track A: Ones for people who are pretty much screwed or have something so malignant that the cure most certainly isn't worse then the disease....

meanwhile Track B: for general public consumption as it were that takes its time and makes sure that it "Does no harm"

And track C that does monthly, then quarterly, then yearly, etc reviews of the drug and reports on its effectiveness, side effects, etc. (Hmmm do they do this already? Inquiring minds want to know.)




"We don't know how to make a $500 computer that's not a piece of junk." -- Apple CEO Steve Jobs













botimage
Copyright 2015 DailyTech LLC. - RSS Feed | Advertise | About Us | Ethics | FAQ | Terms, Conditions & Privacy Information | Kristopher Kubicki