Image via Wikipedia Nanoparticle Cancer Treatments 100% Eradication
by James Rickman
Nanoshell therapy is comprised of three components:
- an off-the-shelf near infrared laser source
- an off-the-shelf interstitial fiber optic probe delivers the laser energy to a site near or inside the tumor
- the investigational nanoshell particles, a near-infrared absorbing, inert material designed to absorb and convert the laser energy into heat.
The nanoshell treatment may be used with an FDA-cleared laser that emits near infrared energy with the clinical study specified parameters (power, duty cycle, treatment time) and with an FDA-cleared fiber optic probe for energy. Nanoshell particles consist of a gold metal shell and a non-conducting, or dielectric, silica core and serves as the exogenous absorber of the near infrared laser energy delivered by the fiber.
Nanoshell particles are administered intravenously and because of their small size they are specifically able to enter the tumor through its leaky vasculature. This process is known as the enhanced permeability and retention effect and is well documented for many solid tumors. The particles are unable to exit normal vasculature and therefore do not accumulate in healthy tissue.
After the particles accumulate in the tumor, the area is illuminated with a near-infrared laser at wavelengths chosen to allow the maximum penetration of light through tissue. The nanoparticles are specifically designed to absorb this wavelength and convert the laser light into heat. This results in the ablation of the tumor.
History of Nanoshells
Dr. Naomi Halas Ph. D, a professor at Rice University, invented the tiny (Nanoshell) particles, with a glass core and gold covered shell, in the 1990's. Now Halas and her colleagues have figured out a way to make nanoshells smarter. They've attached a bright fluorescent dye to the particles that make them glow under infrared light. They've also added a magnetic shell that makes the particles visible to MRI. In addition, researchers can now attach antibodies to the nanoparticles that help them hone-in on a variety of cancer cells.
"If you try to do the same thing with molecules or with drugs, it's very difficult, if not impossible, to attach several different functions to the same drug without disrupting its first function. But with nano-particles you have a nice platform that you can add several different things to it and still preserve the primary function of the nano-particle itself." http://www.pbs.org/wgbh/nova/sciencenow/3209/03-nanoshells.html
At this point, laser light converts that light to heat, and then kill tumor cells with that heat. Halas says being able to watch the progress of the nano-particles, both optically and magnetically, is crucial to manage the process.
"In terms of being able to facilitate medical treatments with this approach, this type of tool is going to be very good. It gives eyes to the medical research. It gives two sets of eyes to the medical research, the optical eyes and the magnetic eyes. Those in combination complement each other so more information will be available using this approach." http://www.tcrt.org/c3018/c4130/Nanoshell-Enabled-Photonics-Based-Imaging-and-Therapy-of-Cancer-p-33-40-p12032.html
FDA Nanoparticle Approval Process
The future of nanoshell cancer treatment involves exhaustive studies on hundreds of varying subjects and optimize the shape and the surface properties of these nanoshells so that it gets favorable bio-distribution where most of the stuff retains in the tumor and its clear of the liver and kidneys to the body. Once that is done, it should be ready for pursuing the FDA approval (5-7 years) process working with clinicians and exiting human trials to potentially become the standard in cancer treatment.
Breakthrough noninvasive cancer therapy combines the unique physical and optical properties of nanoshells or nanoparticles with a infrared laser source to thermally destroy cancer tissue without significant damage to surrounding healthy areas. So far, several laboratory studies proved results of 100% complete eradication of tumors with little surrounding tissue damage and no side effects, related FDA reports.
Nanoshell particles are investigational at this current time and only available through designated FDA sanctioned clinical study sites. http://www.fda.gov/ScienceResearch/SpecialTopics/RunningClinicalTrials/default.htm
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