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Researchers develop method to liquefy tumors using sound waves, safely treating cancer
• http://www.naturalnews.com(NaturalNews) A new ultrasound technique is being developed that may allow cancerous tumors to be liquefied without the use of chemotherapy or electromagnetic radiation. Astonishingly, recent research into this technique conducted by scientists from the University of Washington suggests that it may also eventually allow full regeneration of damaged tissue or organs.
The findings were presented at the 168th meeting of the Acoustical Society of America (ASA) in Indianapolis in October.
The technique in question, known as histotripsy, uses ultrasound to mechanically destroy cancerous or other targeted tissues. This is a departure from traditional ultrasound therapy, which destroys tissues using heat.
Tumor-destroying technique uses currently available technology
In histotripsy, ultrasound-induced vibration leads to the production of bubbles formed from dissolved gases. If the vibration continues at high enough intensities, the bubbles eventually collapse, release a shock wave that can completely liquefy cells. A series of these collapses (known as inertial cavitation) can destroy a vast section of tissue, such as a tumor. Scientists can accelerate the process by injecting microbubbles into the tissue before the procedure.
Studies have shown that histotripsy can totally liquefy tumors, and can do so with remarkable precision and minimal impact on healthy surrounding tissue.
To date, three forms of histotripsy have been developed. The original method, shock scattering histotripsy, uses high intensity pulses ranging in length from 2 to 20 microseconds. More recently, researchers have developed an even more high intensity form, intrinsic threshold histotripsy, which uses pulses only 0.1 to 2 microseconds long.
The University of Washington researchers were experimenting with the third form, known as boiling histotripsy, which combines vibration and heat to produce the same effect as more conventional histotripsy. The main advantage of this technique is that it requires much less energy, and can be more easily produced by adapting existing technology.
In using boiling histotripsy to eliminate cancerous tumors, the researchers expected that once the tumor was liquefied, the body would clear away all traces of it as cellular waste. To their surprise, however, they found that while the tumors in their experiments were indeed utterly destroyed, in some cases the underlying extracellular structure remained.
"In some of our experiments, we discovered that some of the stromal tissue and vasculature was being left behind," researcher Yak-Nam Wang said. "So we had the idea about using this to decellularize tissues for tissue engineering and regenerative medicine."
May hold the key to organ regeneration
The surviving structure, known as the extracellular matrix, is the fibrous network that cells use to guide their growth. An intact extracellular matrix could hypothetically be seeded with stem cells, allowing the regrowth of new, healthy tissue.
For that reason, scientists have searched for decades for a way to remove tissue without destroying the extracellular matrix. Yet nearly all methods currently used to destroy cells also damage the surrounding tissues and fibers. They also take much longer than histotripsy.