Reading this article one must read between the lines. The authors are working overtime to not raise expectations. Yet we are describing a mechanical system that impacts tumors specifically in a way that allows a whole body attack without impacting much else.
The method appears likely to work on most major tumors. In fact we immediately narrow ourselves down to cancers of the liver and spleen only as problematic and perhaps leukemia. Any tumor needing a blood supply is completely vulnerable.
Mouse tests worked completely.
A range of strategies and protocols are discussed but all are secondary to the principal discovery. We can inject gold nanorods into the bloodstream, wait a few hours and then successfully induce warming in localized tumors. We likely cannot get away with a full body scan while we are at it but this is more than good enough. Objectively, a workable protocol can be designed plausibly for all cancers.
I do not see the long development cycle been maintained for this therapy. The metal itself has a long history of human usage. The various coatings will have solid histories also. Then it will be applied first to terminal patients. After which the ethical burden switches to the other side of the argument.
After all, if thirty terminal lung cancer patients are outright cured, it is obscene to withhold treatment of the thousands dying from the disease.
Besides, why would you not try this method before surgery or chemotherapy? They are both clearly harmful in application while this method is most likely not harmful in the least.
We have a completely new mechanical method of surgical removal of cancerous cells. If we are lucky, it will take out all colonies of daughter cells also. Most likely, it will reduce populations well below what is necessary for a supported immune system needs to finish the job.
In my opinion, if we cannot beat cancer with this magic bullet, then we are hopeless. At worst, we will have to work at it in some cases. Best is that there is no biological sidestep to a mechanical solution as has been shown on almost every biochemical method ever applied. We may have actually won the war on cancer with this simple trick.
Targeting tumors using tiny gold particles
Gold nanorods could detect, treat cancer
Anne Trafton, MIT News Office
October 27, 2009
MIT researchers developed these gold nanorods that absorb energy from near-infrared light and emit it as heat, destroying cancer cells.
Photo / Sangeeta Bhatia Laboratory; MIT
Photo / Sangeeta Bhatia Laboratory; MIT
May 4, 2009
It has long been known that heat is an effective weapon against tumor cells. However, it's difficult to heat patients' tumors without damaging nearby tissues.
Now, MIT researchers have developed tiny gold particles that can home in on tumors, and then, by absorbing energy from near-infrared light and emitting it as heat, destroy tumors with minimal side effects.
Such particles, known as gold nanorods, could diagnose as well as treat tumors, says MIT graduate student Geoffrey von Maltzahn, who developed the tumor-homing particles with Sangeeta Bhatia, professor in the Harvard-MIT Division of Health Sciences and Technology (HST) and in the Department of Electrical Engineering and Computer Science, a member of the David H. Koch Institute for Integrative Cancer Research at MIT and a Howard Hughes Medical Institute Investigator.
Von Maltzahn and Bhatia describe their gold nanorods in two papers recently published in Cancer Research and Advanced Materials. In March, von Maltzahn won the Lemelson-MIT Student Prize, in part for his work with the nanorods.
Cancer affects about seven million people worldwide, and that number is projected to grow to 15 million by 2020. Most of those patients are treated with chemotherapy and/or radiation, which are often effective but can have debilitating side effects because it's difficult to target tumor tissue.
With chemotherapy treatment, 99 percent of drugs administered typically don't reach the tumor, said von Maltzahn. In contrast, the gold nanorods can specifically focus heat on tumors.
"This class of particles provides the most efficient method of specifically depositing energy in tumors," he said.
Wiping out tumors
Gold nanoparticles can absorb different frequencies of light, depending on their shape. Rod-shaped particles, such as those used by von Maltzahn and Bhatia, absorb light at near-infrared frequency; this light heats the rods but passes harmlessly through human tissue.
In a study reported in the team's Cancer Research paper, tumors in mice that received an intravenous injection of nanorods plus near-infrared laser treatment disappeared within 15 days. Those mice survived for three months with no evidence of reoccurrence, until the end of the study, while mice that received no treatment or only the nanorods or laser, did not.
Once the nanorods are injected, they disperse uniformly throughout the bloodstream. Bhatia's team developed a polymer coating for the particles that allows them to survive in the bloodstream longer than any other gold nanoparticles (the half-life is greater than 17 hours).
In designing the particles, the researchers took advantage of the fact that blood vessels located near tumors have tiny pores just large enough for the nanorods to enter. Nanorods accumulate in the tumors, and within three days, the liver and spleen clear any that don't reach the tumor.
During a single exposure to a near-infrared laser, the nanorods heat up to 70 degree Celsius, hot enough to kill tumor cells. Additionally, heating them to a lower temperature weakens tumor cells enough to enhance the effectiveness of existing chemotherapy treatments, raising the possibility of using the nanorods as a supplement to those treatments.
The nanorods could also be used to kill tumor cells left behind after surgery. The nanorods can be more than 1,000 times more precise than a surgeon's scalpel, says von Maltzahn, so they could potentially remove residual cells the surgeon can't get.
Finding tumors
The nanorods' homing abilities also make them a promising tool for diagnosing tumors. After the particles are injected, they can be imaged using a technique known as Raman scattering. Any tissue that lights up, other than the liver or spleen, could harbor an invasive tumor.
In the Advanced Materials paper, the researchers showed they could enhance the nanorods' imaging abilities by adding molecules that absorb near-infrared light to their surface. Because of this surface-enhanced Raman scattering, very low concentrations of nanorods - to only a few parts per trillion in water [gf1]- can be detected.
Another advantage of the nanorods is that by coating them with different types of light-scattering molecules, they can be designed to simultaneously gather multiple types of information - not only whether there is a tumor, but whether it is at risk of invading other tissues, whether it's a primary or secondary tumor, or where it originated.
Bhatia and von Maltzahn are looking into commercializing the technology. Before the gold nanorods can be used in humans, they must undergo clinical trials and be approved by the FDA, which von Maltzahn says will be a multi-year process.
Other authors of the Advanced Materials paper are Andrea Centrone, postdoctoral associate in chemical engineering; Renuka Ramanathan, undergraduate in biological engineering; Alan Hatton, the Ralph Landau Professor of Chemical Engineering; and Michael Sailor and Ji-Ho Park of the University of California at San Diego.
Park and Sailor are also authors of the Cancer Research paper, along with Amit Agrawal, former postdoctoral associate in HST; and Nanda Kishor Bandaru and Sarit Das of the Indian Institute of Technology Madras.
The research was funded by the National Institutes of Health, the Whitaker Foundation and the National Science Foundation. Nanopartz Inc. supplied gold nanoparticles, gold nanowires and the precursor gold nanorods used in this work.
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