Researchers successfully tested gold nanotubes which can detect and destroy cancer cells

Researchers successfully tested gold nanotubes which can detect and destroy cancer cells

There's no doubt that doctors would prefer to treat cancer as soon as they spot it, and it looks like nanotechnology might give them that chance. Researchers at the University of Leeds have successfully tested gold nanotubes that are useful for both imaging and destroying cancer cells. Since the tubes absorb near-infrared light frequencies, which both generate heat and render human skin transparent, you only need to zap them with lasers of varying brightness to achieve multiple ends. You can use a relatively low brightness to reveal tumors, while high brightness will heat the tubes enough to kill nearby tumorous cells. The shape also has room for drugs, so you can deliver medicine at the same time.


Image credit: Jing Claussen (iThera Medical, Germany)

Nanotubes made of gold can act as probes for high-res imaging, drug delivery vehicles and agents for destroying cancer cells claim scientists in a new paper that tested the nanoparticles in mice. A study published in the journal Advanced Functional Materials, details the first successful demonstration of the bio medical use of gold nanotubes in a mouse model of human cancer and could soon be heading for clinical trials. “High recurrence rates of tumours after surgical removal remain a formidable challenge in cancer therapy. Chemoor radiotherapy is often given following surgery to prevent this, but these treatments cause serious side effects,” said Sunjie Ye study lead author from the University of Leeds.

Gold nanotubes ­ that is, gold nanoparticles with tubular structures that resemble tiny drinking straws ­ have the potential to enhance the efficacy of these conventional treatments by integrating diagnosis and therapy in one single system.” The researchers say that a new technique to control the length of nanotubes underpins the research. By controlling the length, the researchers were able to produce gold nanotubes with the right dimensions to absorb a type of light called `near infrared'.

“Human tissue is transparent for certain frequencies of light ­ in the red infrared region. This is why parts of your hand appear red when a torch is shone through it,” said the study's corresponding author Steve Evans. “When the gold nanotubes travel through the body, if light of the right frequency is shone on them they absorb the light. This light energy is converted to heat, rather like the warmth generated by the Sun on skin. Using a pulsed laser beam, we were able to rapidly raise the temperature in the vicinity of the nanotubes so that it was high enough to destroy cancer cells.” In cell-based studies, by adjusting the brightness of the laser pulse, the researchers say they were able to control whether the gold nanotubes were in cancer-destruction mode, or ready to image tumours.

In order to see the gold nanotubes in the body, the researchers used a new type of imaging technique called `multispectral optoacoustic tomography' (MSOT) to detect the gold nanotubes in mice, in which gold nanotubes had been injected intravenously. It is the first biomedical application of gold nanotubes within a living organism. It was also shown that gold nanotubes were excreted from the body and therefore are unlikely to cause problems in terms of toxicity, an important consideration when developing nanoparticles for clinical use.

“This is the first demonstration of the production, and use for imaging and cancer therapy, of gold nanotubes that strongly absorb light within the `optical window' of biological tissue,” said study co-author James McLaughlan. “The nanotubes can be tumour-targeted and have a central `hollow' core that can be loaded with a therapeutic payload. This combination of targeting and localized release of a therapeutic agent could, in this age of personalized medicine, be used to identify and treat cancer with minimal toxicity.” The use of gold nanotubes in imaging and other biomedical applications is currently progressing through trial stages towards early clinical studies.

Via: EurekAlert
Source: University of Leeds

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