Gold Nanostars - The Future of Cancer Detection

Gold Nanostars, couple of nanometers in size and might take thousands of them to span diameter of human hair and yet could be effective in fighting tumor. Nanotechology has shown a promising offer, a new possibilities for cancer therapy. 

Photo courtesy of  CrystEngComm Blog

Since my initial research, searching for efficient ways to address cancer detection has prompted enormous progress. On a global scale, by 2030 there will be 21.7 million new cases of cancer and 13 million cancer-related deaths. This health burden is likely to increase if we fail to make the necessary changes in the early detection of cancer. For years, now, cancer has been studies as a laboratory problem, but, while much has been learned, we are still some distance short of having discovered its cause. This being the case, we must still, perforce, rely upon already existing clinical knowledge-diagnosis, operation, irradiation -the indispensable triad. Of these three the greatest is, "diagnosis;" but this is only fully effective when it is early. We all agree that, taken in time, and when in an accessible position, cancer is curable. Therefore, for us "the basic aim must be the recognition of cancer at a stage so early that it can be destroyed or excised before it has time to spread to distant structures. 

We may take it for granted that every doctor is fully alive to the importance of the early signs of cancer. In spite of this, however, "every consulting physician and surgeon can point to many cases where the family physician failed to grasp the possible meaning of the signs and symptoms complained of by the patient until the disease had progressed to an inoperable stage." This statement may seem to imply a reflection on the ability of the average family doctor.

But if diagnosis should be early it should also be accurate. In this context, gold-based nanomaterials are particularly useful because of their enhanced optical properties including strong light absorption and scattering in the visible and near-infrared (NIR) wavelength regions, biocompatibility, colloidal and chemical stabilities, and ability to be widely functionalized. Specifically, gold nanostructures have been investigated as suitable platforms for multimodality therapy due to the possibility of combining chemotherapy.

A variety of gold anisotropic nanoparticles in the form of rods, cages, hollow spheres, shells, or branched particles, the so-called “tissue therapeutic window”, because of the lower optical attenuation from water and blood components within this spectral range (650−900 nm). Gold Nanoparticles can induce cytotoxic hyperthermia upon NIR laser irradiation, increasing the local temperature above 43 °C, which kills malignant cells through apoptosis or necrosis. Also, anisotropic NPs with long blood circulation times can be passively or actively concentrated in the tumor region by means of an enhanced permeability and retention (EPR) effect and/or decoration with specific biotargeting elements, respectively.

Gold nanostars are nanoparticles cleverly designed. It is made of gold and shaped much like a star and are particularly interesting thanks to, their ease of synthesis for large-scale production and size tunability, their window for deep bioimaging and great potential for energy absorption due to high cross-section ratios for efficient photothermal transduction, their large surface-to volume ratios useful for improving drug loading, and their multiple sharp branches acting as “hot-spots” for (bio)sensing. Apart from their great interest in biomedical fields these nanoparticles have found important applications during the past years as single therapeutic probes to fight against tumors. 

In this regard, the highly branched structure and large specific surface area lead to larger cargo loading rates, allows the researchers to load a high concentration of drug molecules onto the nanostar. Less drug would be needed than current therapeutic approaches using free molecules because the drug is stabilized on the surface of the nanoparticle. In addition to allowing a large amount of drug to be loaded, the nanostar’s shape also helps concentrate the light at the points, facilitating drug release in those areas. Drug release from nanoparticles is a difficult problem, but with the gold nanostars the release occurs easily.

Medicine might well be the most exciting area where nanotech can be put to use. The nanostars are attracted to proteins on the cancer cells' exteriors. The proteins helpfully deliver the nano-sized invaders directly to the nucleus. Once attached to the nucleus, a shot of light from a laser releases the drug from the nanostars, and it starts working on the nucleus. That won't be a pretty time to be a cancer cell.

Understanding Gold Nano-Particles

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Colloidal gold is sub-micrometer nano-particles of gold suspended in a fluid, usually water. Colloidal gold is not a new way of using nano gold, in fact, before the birth of Jesus Christ (BC), colloidal gold was used to make Ruby Red Glass. Colloidal gold has also been used to make stained glass because of the vibrant colors it creates through its interaction with visible light.

Some studies have been done about taking Colloidal Gold orally, but without a doctor's advice, it is not advised. In addition, to coloring glass, colloidal gold and silver have been used since the Middle Ages as an oral 'cure-all,' however today, many believe it to be as good as 'snake's oil,' while others still believe that it helps those who suffer from arthritis, depression, and drug addictions.

How Big is a Nano-Particle?

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Gold Nano-Particles range in the size from one nm in size to several hundred Nano-meters in size. To help you understand the size of a Nano-meter, 1 Nano-meter is one billionth of a meter. 

To better understand this visually, take a look at the picture to the right, 100,000 nano-particles, the size of one Nano-meter, can fit within the width of one human hair.

Gold Nano-Particle Shapes

Photo courtesy of Royal Society of Chemistry

Researchers are using several different shapes and sizes in this technology.  It is still being determined what shape works best for killing cancerous cells. Gold Nano-particles come in a wide variety of shapes, including, sphere, rod, star and triangle, nano-triangles are also referred to as nano-pyramids.

However, although Gold Nano-Rods, Stars and Triangles behave similarly to the gold nano-Spheres, their shapes optimize their light scattering characteristics. In addition, Gold Nano-Rods have also been proven to enter a tumor more readily, than spheres.

How Do Gold Nano-particles
Target & Terminate Cancer Cells?

Targeting Cancer with Gold Nano-Particles

Photo courtesy of  BioOptics World

Researchers enhance Gold Nano-Particle's Enhanced Permeability and Retention effect by adding antibodies that contain bio-markers that will help them seek out cancer cells. Once the antibodies find the cancerous cells in the body, the antibodies attach themselves to the tumor.

What are the Most Common Forms of GNPs Cancer                                     Research 

Photo courtesy of  Free-Investment

Currently, there are several different methods used to kill cancer cells using Gold Nano-particles.

Below, you'll find information about three of the most common methods researchers use to kill cancer cells with gold nano-particles. 

Further down the page, is a list of the latest articles on Gold Nano-Particle Cancer Research.

Gold Nano-Particles
Infrared Light & Lasers

Lasers and Infrared light are one of the most common methods researchers use to kill cancer cells with gold nano-particles.

In this research, a test subject (mouse) has a cancerous tumor; the mouse is injected with gold nano-particles treated with Antibodies to seek out the cancer cells.

Once the researchers make sure that the gold nano-particles have reached the cancerous cells, by taking x-rays of the treated subject, they direct the light in the direction of the Tumor filled with the Gold Nano-Particles. 

Through Surface Plasmon Resonance the light heats the gold nano-particles, killing cancer cells, and destroying the tumor. 

This happens with little or no damage done to healthy tissue.

GNPs & Drugs

Another common method of research using Gold Nano-Particles is to attach or infuse the GNPs with a drug or radiation. 

The researchers attach antibodies to the GNPs that also contain a DNA shell that instructs the shell to open once the GNPs have entered into their cancer target, delivering the drug.

There has been a lot of research using chemotherapy drugs attached to Gold Nano-Particles.  So far this research has shown the drug killing the tumor, with a lot less of the harmful effects associated with chemotherapy.