CAHT Newsletter Misuse of Medical Technology

This is one of the most egregious forms of misuse of medical technology. Many people have written emails testifying to the fact that they are being heated inside and outside with some form of radiation. While radiation can cause skin burns, the type of remote stimulation being used to activate implants is used in cancer therapy. The necessary ingestion of nanoparticles are part of the covert program injection Targeted Individuals with nanoparticles without their knowledge or consent. The particles are activated remotely using frequencies.

One type is Photothermal therapy (PTT) which refers to efforts to use electromagnetic radiation (most often in infrared wavelengths) for the treatment of various medical conditions, including cancer. This approach is an extension of photodynamic therapy, in which a photosensitizer is excited with specific band light. This activation brings the sensitizer to an excited state where it then releases vibrational energy (heat), which is what kills the targeted cells. Unlike photodynamic therapy, photothermal therapy does not require oxygen to interact with the target cells or tissues. Current studies also show that photothermal therapy is able to use longer wavelength light, which is less energetic and therefore less harmful to other cells and tissues.

Most materials of interest currently being investigated for photothermal therapy are on the nanoscale. One of the key reasons behind this is the enhanced permeability and retention effect observed with particles in a certain size range (typically 20 – 300 nm).

Gold nanoparticles

One of the most promising directions in photothermal therapy is the use of gold nanoparticles. Initial efforts with gold nanoparticles, however, were not very effective in vivo because the spherical particles used had peak absorptions limited to 520 to 580 nm for particles ranging from 10 to 100 nm in diameter, respectively. These wavelengths were not effective in vivo because skin, tissues, and hemoglobin have a transmission window from 650 to 900 nm, with peak transmission at approximately 800 nm (known as the Near-Infrared Window).

Hollow Gold Nanospheres (HGNs)

A novel metal nanostructure, namely hollow gold nanospheres (HGNs or AuNSs), has been recently developed and successfully used for photothermal ablation therapy (PTA) in vitro and in vivo. The HGNs have a unique combination of small size (30-50 nm in outer diameter and 3-6 nm shell thickness), spherical shape, highly uniform shell, and strong, narrow, and tunable near IR absorption. The high optical quality of the HGNs is mainly due to the high uniformity of the Au shell, which is generated using highly uniform Co nanoparticles as a template.

Gold NanoRods (AuNR)

When AuNP are exposed to NIR light, the oscillating electromagnetic field of the light causes the free electrons of the AuNP to collectively coherently oscillate. Changing the size and shape of AuNP, changes the wavelength that gets absorbed. A desired wavelength would be between 700-1000 nm because biological tissue is optically transparent at these wavelengths. While all AuNP properties are sensitive to change in their shape and size, Au nanorods properties are extremely sensitive to any change in any of their dimensions regarding their length and wide or their aspect ratio. When light is shown on a metal NP, the NP forms a dipole oscillation along the direction of the electric field. When the oscillation reaches its maximum, this frequency is called the surface plasmon resonance (SPR). AuNR have two SPR spectrum bands: one in the NIR region caused by its longitudinal oscillation which tends to be stronger with a longer wavelength and one in the visible region caused by the transverse electronic oscillation which tends to be weaker with a shorter wavelength. The SPR characteristics account for the increase in light absorption for the particle. As the AuNR aspect ratio increases, the absorption wavelength is redshifted and light scattering efficiency is increased. The electrons excited by the NIR lose energy quickly after absorption via electron-electron collisions, and as these electrons relax back down, the energy is released as a phonon that then heats the environment of the AuNP which in cancer treatments would be the cancerous cells. This process is observed when a laser has a continuous wave onto the AuNP. Pulsed laser light beams generally results in the AuNP melting or ablation of the particle. Continues wave lasers take minutes rather than a single pulse time for a pulsed laser, continues wave lasers are able to heat larger areas at once.

Gold Nanoshells

Loo et al. investigated gold nanoshells, coating silica nanoparticles with a thin layer of gold. The authors conjugated antibodies (anti-HER2 or anti-IgG) to these nanoshells via PEG linkers. After incubation of SKBr3 cancer cells with the gold nanoshells, an 820 nm laser was used to irradiate the cells. Only the cells incubated with the gold nanoshells conjugated with the specific antibody (anti-HER2) were damaged by the laser.

Graphene and graphene oxide

Yang et al. demonstrated the viability of graphene for photothermal therapy in 2010 with in vivo mice models. An 808 nm laser at a power density of 2 W/cm2 was used to irradiate the tumor sites on mice for 5 minutes. As noted by the authors, the power densities of lasers used to heat gold nanorods range from 2 to 4 W/cm2. Thus, these nanoscale graphene sheets require a laser power on the lower end of the range used with gold nanoparticles to photothermally ablate tumors.

In 2012, Yang et al. incorporated the promising results regarding nanoscale reduced graphene oxide reported by Robinson et al. into another in vivo mice study. The therapeutic treatment used in this study involved the use of nanoscale reduced graphene oxide sheets, nearly identical to the ones used by Robinson et al. (but without any active targeting sequences attached). Nanoscale reduced graphene oxide sheets were successfully irradiated in order to completely destroy the targeted tumors. Most notably, the required power density of the 808 nm laser was reduced to 0.15 W/cm2, an order of magnitude lower than previously required power densities. This study demonstrates the higher efficacy of nanoscale reduced graphene oxide sheets as compared to both nanoscale graphene sheets and gold nanorods.

Future directions

Some research has indicated problems with aggregation of the photosensitizers, local shock waves, hyperthermic effects, but otherwise little phototoxicity. Many potential side effects and complications, as well as other potential applications of photothermal therapy, are yet to be discovered.
See Wiki Photothermal and Hyperthermic Therapy which use Nanoparticles to cause heating

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