From one of my favourite newsletters, The Harrow Group Technology Report, comes this article on nanospheres, tiny little bits of material that were used in an amazingly successful cancer killing experiment:

As published in pages 171 – 176 of Issue 2 of the June 25   Cancer Letters  (an abstract is freely available while the full text requires a subscription), and summarized in a June 21, 2004 Rice University   press release, the researchers created silica spheres 20-times smaller than a blood cell and then added a surface layer of gold.  One characteristic of these spheres is that, depending on their size and the ratio of silica to gold, they can be “tuned” to respond to particular wavelengths of light.  In this case they’re sensitive to near-infrared light, which passes through normal tissue without hindrance and without causing damage.

Once injected into the veins of test mice that all had significant cancer tumors, the researchers waited six hours for the nanospheres to circulate through the body.  Because of a characteristic of cancer tumors, that their internal blood vessels are poorly formed and tend to leak fluid into the surrounding tissue (the tumor), the gold nanospheres tended to collect within the tumors.  Then, the researchers applied a near-infrared laser to the skin over the tumor areas.  Although the healthy tissue was not affected, the nanospheres became quite hot as they absorbed the near-infrared light, raising the temperature in the tumor tissue by  “around 50-degrees C”.  And the tumors were destroyed.  (When the laser was applied to areas that did not have nanosphere-holding tumors below them, there was virtually no temperature change.)

Within ten days, the nanosphere-treated group of mice was cancer-free and continued to live a normal lifespan!

 On the other hand, the tumors in two control groups (one receiving only saline injections plus the near-infrared light, and another group receiving no treatment), continued to grow “rapidly,” causing the mice in these two groups to die in 10 to 12 days respectively.