David Kirkpatrick

May 5, 2010

Providing disadvantages along with advantages helps nanotech acceptance

One of my more popular all time posts is “Nanotechnology does have drawbacks” from September 2008 so that tells me people regularly search for the negative side of nanotech. The topic is something that heads toward higher level science and the term gets tossed around a lot — and a lot of the time incorrectly as far as that goes — so people are naturally curious about exactly what is nanotechnology and how is it good and bad.

This survey, not surprisingly, found that providing information about the risks of nanotech increases public support among those who have heard of the field. Of course it also found support decreased among those who’d never heard the term once they were frightened by the potential drawbacks. I’m guessing scientific fact that sounds like scientific fiction can be pretty scary to someone who’s not familiar with what it can, and might, do both positive and negative.

From the second link, the release:

Survey: Hiding Risks Can Hurt Public Support For Nanotechnology

Release Date: 05.04.2010

A new national survey on public attitudes toward medical applications and physical enhancements that rely on nanotechnology shows that support for the technology increases when the public is informed of the technology’s risks as well as its benefits – at least among those people who have heard of nanotechnology. The survey, which was conducted by researchers at North Carolina State University and Arizona State University (ASU), also found that discussing risks decreased support among those people who had never previously heard of nanotechnology – but not by much.

“The survey suggests that researchers, industries and policymakers should not be afraid to display the risks as well as the benefits of nanotechnology,” says Dr. Michael Cobb, an associate professor of political science at NC State who conducted the survey. “We found that when people know something about nanotechnologies for human enhancement, they are more supportive of it when they are presented with balanced information about its risks and benefits.”

The survey was conducted by Cobb in collaboration with Drs. Clark Miller and Sean Hays of ASU, and was funded by the Center for Nanotechnology in Society at ASU.

However, talking about risks did not boost support among all segments of the population. Those who had never heard of nanotechnology prior to the survey were slightly less supportive when told of its potential risks.

In addition to asking participants how much they supported the use of nanotechnology for human enhancements, they were also asked how beneficial and risky they thought these technologies would be, whether they were worried about not getting access to them, and who should pay for them – health insurance companies or individuals paying out-of-pocket. The potential enhancements addressed in the survey run the gamut from advanced cancer treatments to bionic limbs designed to impart greater physical strength.

One segment of participants was shown an image of an unrealistic illustration meant to represent a nanoscale medical device. A second segment was shown the image and given a “therapeutic” framing statement that described the technology as being able to restore an ill person to full health. A third segment was given the image, along with an “enhancement” framing statement that described the technology as being able to make humans faster, stronger and smarter. Two additional segments were given the image, the framing statements and information about potential health risks. And a final segment of participants was not given the image, a framing statement or risk information.

The survey found that describing the technology as therapeutic resulted in much greater public support for the technology, as well as a greater perception of its potential benefits. The therapeutic frame also resulted in increased support for health insurance coverage of nanotech treatments once they become available, and increased concerns that people wouldn’t be able to afford such treatments without insurance coverage.

“These findings suggest that researchers, policymakers and industries would be well advised to focus their research efforts on developing therapeutic technologies, rather than enhancements, because that is the area with the greatest public support,” Cobb says.

The use of the nanotech image did not have a significant overall impact on participants’ support, but did alarm people who were not previously familiar with nanotechnology – making them less likely to support it.

The survey was conducted by Knowledge Networks between April 2-13. The survey included 849 participants, and has a margin of error of plus or minus 3.3 percent.

NC State’s Department of Political Science is part of the university’s College of Humanities and Social Sciences.

This illustration was used to represent a nanoscale medical device in the national survey on public attitudes towards the use of nanotechnology for human enhancement.This illustration was used to represent a nanoscale medical device in the national survey on public attitudes towards the use of nanotechnology for human enhancement.

March 17, 2010

DNA nanotubes as a drug delivery system

Medical nanotech news from McGill University.

The release:

DNA nanotechnology breakthrough offers promising applications in medicine

McGill researchers create DNA nanotubes able to carry and selectively release materials

This release is available in French.

A team of McGill Chemistry Department researchers led by Dr. Hanadi Sleiman has achieved a major breakthrough in the development of nanotubes – tiny “magic bullets” that could one day deliver drugs to specific diseased cells. Sleiman explains that the research involves taking DNA out of its biological context. So rather than being used as the genetic code for life, it becomes a kind of building block for tiny nanometre-scale objects.

Using this method, the team created the first examples of DNA nanotubes that encapsulate and load cargo, and then release it rapidly and completely when a specific external DNA strand is added. One of these DNA structures is only a few nanometres wide but can be extremely long, about 20,000 nanometres. (A nanometre is one-10,000th the diameter of a human hair.)

Until now, DNA nanotubes could only be constructed by rolling a two-dimensional sheet of DNA into a cylinder. Sleiman’s method allows nanotubes of any shape to be formed and they can either be closed to hold materials or porous to release them. Materials such as drugs could then be released when a particular molecule is present.

One of the possible future applications for this discovery is cancer treatment. However, Sleiman cautions, “we are still far from being able to treat diseases using this technology; this is only a step in that direction. Researchers need to learn how to take these DNA nanostructures, such as the nanotubes here, and bring them back to biology to solve problems in nanomedicine, from drug delivery, to tissue engineering to sensors,” she said.

The team’s discovery was published on March 14, 2010 in Nature Chemistry. The research was made possible with funding from the National Science and Engineering Research Council and the Canadian Institute for Advanced Research.

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On the Web: http://www.hanadisleiman.com

Video link: http://snurl.com/uw2q1

March 13, 2010

More gold nanotech cancer research

I’ve done a lot of blogging on cancer and nanotech and I’ve covered this exact use of gold nanoparticles to destroy tumors. This is new research on the same tech, and this amount of news on one cancer-fighting technique is good medical news. Earlier this week I covered this topic on research from Cornell. Today’s news comes from Washington University in St. Louis.

From the final link, the release:

A golden bullet for cancer

Nanoparticles provide a targeted version of photothermal therapy for cancer

IMAGE: Infrared images made while tumors were irradiated with a laser show that in nanocage-injected mice (left), the surface of the tumor quickly became hot enough to kill cells. In…

Click here for more information.

In a lecture he delivered in 1906, the German physician Paul Ehrlich coined the term Zuberkugel, or “magic bullet,” as shorthand for a highly targeted medical treatment.

Magic bullets, also called silver bullets, because of the folkloric belief that only silver bullets can kill supernatural creatures, remain the goal of drug development efforts today.

A team of scientists at Washington University in St. Louis is currently working on a magic bullet for cancer, a disease whose treatments are notoriously indiscriminate and nonspecific. But their bullets are gold rather than silver. Literally.

The gold bullets are gold nanocages that, when injected, selectively accumulate in tumors. When the tumors are later bathed in laser light, the surrounding tissue is barely warmed, but the nanocages convert light to heat, killing the malignant cells.

In an article just published in the journal Small, the team describes the successful photothermal treatment of tumors in mice.

IMAGE: The color of a suspension of nanocages depends on the thickness of the cages’ walls and the size of pores in those walls. Like their color, their ability to absorb…

Click here for more information.

The team includes Younan Xia, Ph.D., the James M. McKelvey Professor of Biomedical Engineering in the School of Engineering and Applied Science, Michael J. Welch, Ph.D., professor of radiology and developmental biology in the School of Medicine, Jingyi Chen, Ph.D., research assistant professor of biomedical engineering and Charles Glaus, Ph.D., a postdoctoral research associate in the Department of Radiology.

“We saw significant changes in tumor metabolism and histology,” says Welch, “which is remarkable given that the work was exploratory, the laser ‘dose’ had not been maximized, and the tumors were ‘passively’ rather than ‘actively’ targeted.”

Why the nanocages get hot

The nanocages themselves are harmless. “Gold salts and gold colloids have been used to treat arthritis for more than 100 years,” says Welch. “People know what gold does in the body and it’s inert, so we hope this is going to be a nontoxic approach.”

“The key to photothermal therapy,” says Xia, “is the cages’ ability to efficiently absorb light and convert it to heat. ”

Suspensions of the gold nanocages, which are roughly the same size as a virus particle, are not always yellow, as one would expect, but instead can be any color in the rainbow.

They are colored by something called a surface plasmon resonance. Some of the electrons in the gold are not anchored to individual atoms but instead form a free-floating electron gas, Xia explains. Light falling on these electrons can drive them to oscillate as one. This collective oscillation, the surface plasmon, picks a particular wavelength, or color, out of the incident light, and this determines the color we see.

IMAGE: Gold nanocages (right) are hollow boxes made by precipitating gold on silver nanocubes (left). The silver simultaneously erodes from within the cube, entering solution through pores that open in the…

Click here for more information.

Medieval artisans made ruby-red stained glass by mixing gold chloride into molten glass, a process that left tiny gold particles suspended in the glass, says Xia.

The resonance — and the color — can be tuned over a wide range of wavelengths by altering the thickness of the cages’ walls. For biomedical applications, Xia’s lab tunes the cages to 800 nanometers, a wavelength that falls in a window of tissue transparency that lies between 750 and 900 nanometers, in the near-infrared part of the spectrum.

Light in this sweet spot can penetrate as deep as several inches in the body (either from the skin or the interior of the gastrointestinal tract or other organ systems).

The conversion of light to heat arises from the same physical effect as the color. The resonance has two parts. At the resonant frequency, light is typically both scattered off the cages and absorbed by them.

By controlling the cages’ size, Xia’s lab tailors them to achieve maximum absorption.

Passive targeting

“If we put bare nanoparticles into your body,” says Xia, “proteins would deposit on the particles, and they would be captured by the immune system and dragged out of the bloodstream into the liver or spleen.”

To prevent this, the lab coated the nanocages with a layer of PEG, a nontoxic chemical most people have encountered in the form of the laxatives GoLyTELY or MiraLAX. PEG resists the adsorption of proteins, in effect disguising the nanoparticles so that the immune system cannot recognize them.

Instead of being swept from the bloodstream, the disguised particles circulate long enough to accumulate in tumors.

A growing tumor must develop its own blood supply to prevent its core from being starved of oxygen and nutrients. But tumor vessels are as aberrant as tumor cells. They have irregular diameters and abnormal branching patterns, but most importantly, they have thin, leaky walls.

The cells that line a tumor’s blood vessel, normally packed so tightly they form a waterproof barrier, are disorganized and irregularly shaped, and there are gaps between them.

The nanocages infiltrate through those gaps efficiently enough that they turn the surface of the normally pinkish tumor black.

A trial run

In Welch’s lab, mice bearing tumors on both flanks were randomly divided into two groups. The mice in one group were injected with the PEG-coated nanocages and those in the other with buffer solution. Several days later the right tumor of each animal was exposed to a diode laser for 10 minutes.

The team employed several different noninvasive imaging techniques to follow the effects of the therapy. (Welch is head of the oncologic imaging research program at the Siteman Cancer Center of Washington University School of Medicine and Barnes-Jewish Hospital and has worked on imaging agents and techniques for many years.)

During irradiation, thermal images of the mice were made with an infrared camera. As is true of cells in other animals that automatically regulate their body temperature, mouse cells function optimally only if the mouse’s body temperature remains between 36.5 and 37.5 degrees Celsius (98 to 101 degrees Fahrenheit).

At temperatures above 42 degrees Celsius (107 degrees Fahrenheit) the cells begin to die as the proteins whose proper functioning maintains them begin to unfold.

In the nanocage-injected mice, the skin surface temperature increased rapidly from 32 degrees Celsius to 54 degrees C (129 degrees F).

In the buffer-injected mice, however, the surface temperature remained below 37 degrees Celsius (98.6 degrees Fahrenheit).

To see what effect this heating had on the tumors, the mice were injected with a radioactive tracer incorporated in a molecule similar to glucose, the main energy source in the body. Positron emission and computerized tomography (PET and CT) scans were used to record the concentration of the glucose lookalike in body tissues; the higher the glucose uptake, the greater the metabolic activity.

The tumors of nanocage-injected mice were significantly fainter on the PET scans than those of buffer-injected mice, indicating that many tumor cells were no longer functioning.

The tumors in the nanocage-treated mice were later found to have marked histological signs of cellular damage.

Active targeting

The scientists have just received a five-year, $2,129,873 grant from the National Cancer Institute to continue their work with photothermal therapy.

Despite their results, Xia is dissatisfied with passive targeting. Although the tumors took up enough gold nanocages to give them a black cast, only 6 percent of the injected particles accumulated at the tumor site.

Xia would like that number to be closer to 40 percent so that fewer particles would have to be injected. He plans to attach tailor-made ligands to the nanocages that recognize and lock onto receptors on the surface of the tumor cells.

In addition to designing nanocages that actively target the tumor cells, the team is considering loading the hollow particles with a cancer-fighting drug, so that the tumor would be attacked on two fronts.

But the important achievement, from the point of view of cancer patients, is that any nanocage treatment would be narrowly targeted and thus avoid the side effects patients dread.

The TV and radio character the Lone Ranger used only silver bullets, allegedly to remind himself that life was precious and not to be lightly thrown away. If he still rode today, he might consider swapping silver for gold.

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Cancer and nanotechnology

Filed under: Science, Technology — Tags: , , , , — David Kirkpatrick @ 4:43 pm

I’ve been using HubPages as an outlet for print work that I retain the rights to after selling FNASR to a publication that doesn’t archive its content online. Last week I decided to create a hub offering a clearinghouse of all my blogging on cancer and nanotechnology to date in an effort to get a lot of basic information in one place for people interested in the topic. HubPages doesn’t allow more than three links back to one source and blocked that hub after a couple of days. Sadly they’ve not returned a request to waive the rule in this case because the hub’s purpose was purely informational, not link building for my blog. So here is the hub’s contents to get it back out there, and I’ve been forced to amend the original hub with nothing more than a link back to this post. Sorry for the confusion, but do enjoy the material. And a large raspberry to HubPages for zero communication on a hub that probably deserved an exception to an otherwise sensible rule.

The original hub:

At my personal blog I cover a wide range of topics, but four areas get a lot of attention — business (particularly small business), politics, the energy sector (particularly solar energy) and nanotechnology. One place nanotech is really shining in terms of regular breakthroughs and practical applications is in cancer research and treatment. Following is a recap of two years of nanotech/cancer blogging with dates of, links to the original posts and a summary of the key information. If you are interested in the intersection of nanotechnology and cancer research, this hub is a great place to get started.

April 2, 2008 — Researchers at UCLA developed a “nanoimpeller” nanomachine that stores cancer fighting drugs for release inside cancer cells in response to light.

April 3, 2008 — Researchers at Washington University School of Medicine used drug-coated nanoparticles to deliver fumigillin to cancerous tumors at a 1000-times reduced dose while remaining effective. Fumigillin has neurotoxic side effects at standard dosage.

May 8, 2008 — Researcher at UC San Diego, UC Santa Barbara and MIT developed “nanoworms” that can travel through the bloodstream and target tumors — even tumors too small for conventional detection.

July 17, 2008 — Researchers at Georgia Tech developed a treatment that attaches magnetic nanoparticles to free-floating cancer cells allowing those cells to be removed from the body.

July 28, 2008 — More on the Georgia Tech treatment with image.

September 8, 2008 — Nanoscale gold rods are a key component in heat-based cancer treatment. The gold nanoparticles are designed to bind only with cancer cells.

September 29, 2008 — A hybrid technology from researchers headed by the National Cancer Institute’s Alliance for Nanotechnology in Cancer combining a magnetic nanoparticle, a fluorescent quantum dot and an anticancer drug helps to both image and treat cancerous tumors.

February 2, 2009 — Researchers at the University of Texas M.D. Anderson Cancer Center find hollow gold nanospheres containing a targeting peptide track down melanoma cells and penetrate them allowing for treatment with near-infrared light.

November 29. 2009 — A Nature Materials report finds “nanodiscs” made of a nickel-iron alloy can be subjected to a magnetic field to disrupt the membranes of cancer cells and destroy them. Tests found ten minutes of a low magnetic field killed 90% of cancer cells.

January 14, 2010 — Researchers at the National Cancer Institute’s Centers of Cancer Nanotechnology Excellence found two nanoparticles that work in concert to find, bind with and destroy cancer cells. One particle locates and adheres to the tumor and sensitizes the cancer cells for the second nanoparticle that kills the tumor.

February 11, 2010 — This link goes a press release on gold and nanotech. The release mentions gold nanoparticles efficacy in cancer detection and treatment.

February 17, 2010 — Researchers at the University of Missouri created a sensor based on N/MEMS (micro/nanoelectromechanical systems) known as an acoustic resonant sensor that can test for diseases including breast and prostate cancer. The device could lead to a home cancer detection kit.

March 8, 2010 — Researchers at Cornell found nanoparticles made of a dumbbell-shaped two iron oxide particles sandwiching a gold particle can be loaded with an antibody to specifically target cancer cells then become heated by a near infrared laser killing the cells. This treatment is capable of killing cancer cells while leaving nearby healthy cells unharmed.

Keep in mind this hub only covers nanotech/cancer news that caught my eye over the last couple of years. There are breakthroughs happening every day at labs and universities around the world. The field is still in something of its infancy, but nanotechnology in many forms looks like it might be at least one magic bullet in the fight against cancer.

Update: hit this link for all my blog posts on cancer and nanotech.

March 11, 2010

Cancer and nanotechnology

Filed under: Media, Science, Technology — Tags: , , , , , , — David Kirkpatrick @ 2:19 am

I’ve done a lot of blogging over the last two years on the convergence of cancer research/treatment and nanotechnology. Here’s a HubPages hub that serves as a clearinghouse of those posts to date.

Hit this link if you’d prefer to plow though all the posts here on this blog.

Update 3/13/10 — HubPages doesn’t allow multiple links back to one source, so it pulled my original hub and did not respond to a request to waive the otherwise sensible rule in this case as the hub was not a link-building page for this blog, but simply a method to get a lot of information covering a long time period in one place. Hit this link to find the text of the original hub in its entirety.

March 8, 2010

Cancer killing nanotech assassins

Nanotechnology is proving to have many medical applications, and the bulk of those apps are in cancer research. Here’s the latest from Cornell.

The release:

Like little golden assassins, ‘smart’ nanoparticles identify, target and kill cancer cells

ITHACA, N.Y. – Another weapon in the arsenal against cancer: Nanoparticles that identify, target and kill specific cancer cells while leaving healthy cells alone.

Led by Carl Batt, the Liberty Hyde Bailey Professor of Food Science, the researchers synthesized nanoparticles – shaped something like a dumbbell – made of gold sandwiched between two pieces of iron oxide. They then attached antibodies, which target a molecule found only in colorectal cancer cells, to the particles. Once bound, the nanoparticles are engulfed by the cancer cells.

To kill the cells, the researchers use a near-infrared laser, which is a wavelength that doesn’t harm normal tissue at the levels used, but the radiation is absorbed by the gold in the nanoparticles. This causes the cancer cells to heat up and die.

“This is a so-called ‘smart’ therapy,” Batt said. “To be a smart therapy, it should be targeted, and it should have some ability to be activated only when it’s there and then kills just the cancer cells.”

The goal, said lead author and biomedical graduate student Dickson Kirui, is to improve the technology and make it suitable for testing in a human clinical trial. The researchers are now working on a similar experiment targeting prostate cancer cells.

“If, down the line, you could clinically just target the cancer cells, you could then spare the health surrounding cells from being harmed – that is the critical thing,” Kirui said.

Gold has potential as a material key to fighting cancer in future smart therapies. It is biocompatible, inert and relatively easy to tweak chemically. By changing the size and shape of the gold particle, Kirui and colleagues can tune them to respond to different wavelengths of energy.

Once taken up by the researchers’ gold particles, the cancer cells are destroyed by heat – just a few degrees above normal body temperature – while the surrounding tissue is left unharmed. Such a low-power laser does not have any effect on surrounding cells because that particular wavelength does not heat up cells if they are not loaded up with nanoparticles, the researchers explained.

Using iron oxide – which is basically rust – as the other parts of the particles might one day allow scientists to also track the progress of cancer treatments using magnetic resonance imaging, Kirui said, by taking advantage of the particles’ magnetic properties.

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The research was funded by the Sloan Foundation and the Ludwig Institute for Cancer Research, which has been a partner with Cornell since 1999 to bring laboratory work to clinical testing. The research is reported in the Feb. 15 online edition of the journal Nanotechnology.

Text by Anne Ju, Cornell Chronicle

September 8, 2008

Gold nanorods help fight cancer

Filed under: Science, Technology — Tags: , , , , , — David Kirkpatrick @ 11:00 pm

Nanoscale gold rods are a key component in heat-based cancer treatment.

From the link:

Cancer cells are relatively temperature-sensitive. This is exploited in treatments involving overheating of parts of the cancer patient’s body. One highly promising method is photoinduced hyperthermia, in which light energy is converted to heat. Gold nanoparticles absorb light very strongly in the near infrared, a spectral region that is barely absorbed by tissue. The absorbed light energy causes the gold particles to vibrate and is dissipated into the surrounding area as heat. The tiny gold particles can be functionalized so that the specifically bind to tumor cells. Thus, only cells that contain gold particles are killed off.

The problem? Ordinary spherical gold particles do not efficiently convert the light energy into heat; only rod-shaped particles will do. Unfortunately, the additives needed to crystallize the rod-shaped particles from aqueous solutions are cytotoxic.

The team headed by Michael R. Bockstaller is now pursuing a new strategy: instead of aqueous solution, they chose to use an ionic liquid as their medium of crystallization. Ionic liquids are “liquid salts”, organic compounds that exist as oppositely charged ions, but in the liquid state. In this way, the researchers have been able to produce gold nanorods without the use of any cytotoxic additives.

M. Bockstaller and his team have synthesized gold nanorods using an ionic liquid as a solvent. Gold nanorods are interesting starting materials in cancer therapy. (c)Wiley-VCH 2008

M. Bockstaller and his team have synthesized gold nanorods using an ionic liquid as a solvent. Gold nanorods are interesting starting materials in cancer therapy. (c)Wiley-VCH 2008

 

July 23, 2008

Maybe tobacco isn’t all that evil after all …

Filed under: Science — Tags: , , , , , , — David Kirkpatrick @ 5:03 pm

… since there seems to be a therapeutic use in treating certain types of cancer. I’m all for tobacco use in moderation, particularly in the form of long-cut filler cigar or high end pipe tobacco. I’ve even blogged on the joys of pipe smoking here, here, here and here.

From KurzweilAI.net:

Tobacco ‘could help treat cancer’
BBC News, July 21, 2008Stanford University researchers are using tobacco plants to grow key components of a cancer vaccine, turning the plants into factories for an antibody chemical specific to the cancerous cells that cause follicular B-cell lymphoma, a type of non-Hodgkin’s lymphoma.

Once a patient’s cancer cells are isolated in the laboratory, the gene responsible for producing the antibody is extracted and added to a tobacco virus. When the virus infects the tobacco, the gene is added to the plants’ cells, which start producing large quantities of the antibody. These antibodies are put back into a patient to “prime” the body’s immune system to attack any cell carrying them.

 
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