Useful Science Fiction

[R. Richard]

Well, actually science fact. However, a very few years ago this would have been unbelievable scifi. Comment?

Nanotech robots deliver gene therapy through blood

Sun Mar 21, 2:08 pm ET
CHICAGO (Reuters) – U.S. researchers have developed tiny nanoparticle robots that can travel through a patient's blood and into tumors where they deliver a therapy that turns off an important cancer gene.

The finding, reported in the journal Nature on Sunday, offers early proof that a new treatment approach called RNA interference or RNAi might work in people.

RNA stands for ribonucleic acid -- a chemical messenger that is emerging as a key player in the disease process.

Dozens of biotechnology and pharmaceutical companies including Alnylam, Merck, Pfizer, Novartis and Roche are looking for ways to manipulate RNA to block genes that make disease-causing proteins involved in cancer, blindness or AIDS.

But getting the treatment to the right target in the body has presented a challenge.

A team at the California Institute of Technology in Pasadena used nanotechnology -- the science of really small objects -- to create tiny polymer robots covered with a protein called transferrin that seek out a receptor or molecular doorway on many different types of tumors.

"This is the first study to be able to go in there and show it's doing its mechanism of action," said Mark Davis, a professor of chemical engineering, who led the study.

"We're excited about it because there is a lot of skepticism whenever any new technology comes in," said Davis, a consultant to privately held Calando Pharmaceuticals Inc, which is developing the therapy.

Other teams are using fats or lipids to deliver the therapy to the treatment target. Pfizer last week announced a deal with Canadian biotech Tekmira Pharmaceuticals Corp for this type of delivery vehicle for its RNAi drugs, joining Roche and Alnylam.

In the approach used by Davis and colleagues, once the particles find the cancer cell and get inside, they break down, releasing small interfering RNAs or siRNAs that block a gene that makes a cancer growth protein called ribonucleotide reductase.

"In the particle itself, we've built what we call a chemical sensor," Davis said in a telephone interview. "When it recognizes that it's gone inside the cell, it says OK, now it's time to disassemble and give off the RNA."

In a phase 1 clinical trial in patients with various types of tumors, the team gave doses of the targeted nanoparticles four times over 21 days in a 30-minute intravenous infusion.

Tumor samples taken from three people with melanoma showed the nanoparticles found their way inside tumor cells.

And they found evidence that the therapy had disabled ribonucleotide reductase, suggesting the RNA had done its job.

Davis could not say whether the therapy helped shrink tumors in the patients, but one patient did get a second cycle of treatment, suggesting it might be. Nor could he say if there were any safety concerns.

Davis said that part of the study will be presented at the American Society of Clinical Oncology meeting in June.

 

[Handley_Page]

Very interesting.
The idea of accurate delivery of a drug/agent or whatever, to the tumour has been around for ages, but beset by problems. It's looking like some definite progress is being made.

BTW, did anyone see a report about a kid who's having a new (transplanted) wind-pipe?. It seems that all the chemical stuff on the donor's windpipe is washed off and a compound made from the patients own T-cells is applied. A while later it is sewn in place. Theory has it that there should be no need for the regime of anti-suppressant drugs.

http://www.telegraph.co.uk/health/healthnews/7479886/Windpipe-operation-is-major-step-forward-for-transplant-surgery.html

 

[jomar]

This means I need to step up the pace on getting my future Nebula award winning story edited and submitted.

 

[stephen55]

Don't like that word "Robot"...

A little pause and reflect is in order. Nanotechnology...yes. Robots...no. Wrapping drug A in substance B doesn't give you a robot. It gives you A inside B. As long as B is carefully chosen to adhere to surface C, and allow A to get inside C, you've got a viable drug delivery model. The trick, seldom realized, is to get B to C and only to C. The next trick, seldom realized is to get A inside C and only C.

In reality B can go all over the place and A gets into places you'd rather it didn't. Delivering RNA specifically to tumor cells and nothing else has the same problems. The hurdles involved are three. Getting the delivery particle to recognize the tumor cell target, getting the delivery particle to not recognize any other cell and finally getting the RNA into the tumor cell in a way that leaves the RNA unscathed and able to do something.

After all that you have to determine if the RNA is effectively disrupting the the growth of the tumor cells. Alongside that, you have to be sure the RNA isn't getting into and harming healthy cells. It's very complicated stuff and wire services like Reuters like to gloss over the difficulties and use big headlines about Nanotech Robots as if the things have functioning moving parts.

RNA interference is a promising idea that may or may not end up being an effective tool against certain types of tumors. For every ten new research programs at most one or two go on to be viable options. But all is not lost for the other eight or nine. The techniques developed and the obstacles partly or wholly overcome are now new techniques and solved problems that may find there uses in some other project down the road.

My favorite example is Viagra. Until Cialis came along to compete, Viagra was the number one sold drug on the planet. It's still right up there. Years ago it was a failed trial medication being used to control high blood pressure. Go figure!!