Most efforts to improve cancer treatment through nanotechnology are at the research or development stage. However the effort to make these treatments a reality is highly focused. For example, The Alliance for Nanotechnology in Cancer, established by the U.S. National Cancer Institute, is fostering innovation and collaboration among researchers to resolve some of the major challenges in the application of nanotechnology to cancer. In addition, there are many universities and companies worldwide working in this area. It is possible that these efforts will result in cancer becoming being nearly eliminated in a decade or so, in the same way that vaccines nearly eliminated smallpox in the last century.
The next section provides examples of the research underway, a few of the methods discussed have reached the pre-clinical or clinical trial stage.
Cancer Treatments Under Development
One treatment involves targeted chemotherapy that delivers a tumor-killing agent called tumor necrosis factor alpha (TNF) to cancer tumors. TNF is attached to a gold nanoparticle along with Thiol-derivatized polyethylene glycol (PEG-THIOL), which hides the TNF bearing nanoparticle from the immune system. This allows the nanoparticle to flow through the blood stream without being attacked. The company developing this targeted chemotherapy method to deliver TNF and other chemotherapy drugs to cancer tumors is called CytImmune.
One heat therapy to destroy cancer tumors using nanoparticles is called AuroShell™. The AuroShell™ nanoparticles circulate through a patients bloodstream, exiting where the blood vessels are leaking at the site of cancer tumors. Once the nanoparticles accumulate at the tumor the AuroShell™ nanoparticles are used to concentrate the heat from infrared light to destroy cancer cells with minimal damage to surrounding healthy cells. Nanospectra Biosciences has developed such a treatment using AuroShell™ that has been approved for a pilot trial with human patients.
Targeted heat therapy is being developed to destroy breast cancer tumors. In this method antibodies that are strongly attracted to proteins produced in one type of breast cancer cell are attached to nanotubes, causing the nanotubes to accumulate at the tumor. Infrared light from a laser is absorbed by the nanotubes and produces heat that incinerates the tumor.
X-ray therapy may be able to destroy cancer tumors using a nanoparticle called nbtxr3. The nbtxr3 nanoparticles, when activated by x-rays, generate electrons that cause the destruction of cancer tumors to which they have attached themselves. Click here for more details on this method. This is intended to be used in place of radiation therapy with much less damage to healthy tissue. Nanobiotix has released preclinical results for this technique.
An intriguing targeted chemotherapy method uses one nanoparticle to deliver the chemotherapy drug and a separate nanoparticle to guide the drug carrier to the tumor. First gold nanorods circulating through the bloodstream exit where the blood vessels are leaking at the site of cancer tumors. Once the nanorods accumulate at the tumor they are used to concentrate the heat from infrared light; heating up the tumor. This heat increases the level of a stress related protein on the surface of the tumor. The drug carrying nanoparticle (a liposome) is attached to amino acids that bind to this protein, so the increased level of protein at the tumor speeds up the accumulation of the chemotherapy drug carrying liposome at the tumor
Delivery of short interfering RNAs (siRNA) is interesting because siRNA simply stops the cancer tumor from growing and there is the potential to tailor synthetic siRNA to the version of cancer in a individual patient.
Magnetic nanoparticles that attach to cancer cells in the blood stream may allow the cancer cells to be removed before they establish new tumors.
Another method that targets individual cancer cells inserts gold nanoparticles into the cells, then shines a laser on the nanoparticles. The heat explodes the cancer cells.
Using gold nanoparticles to deliver platinum to cancer tumors may reduce the side effects of platinum cancer therapy. The key is that the toxicity level of platinum depends upon the molecule it is bonded to (for the tech types the toxicity depends upon the oxidation state of the platinum). So the researchers chose a platinum containing molecule that has low toxicity to attach to the gold nanoparticles. When the platinum bearing nanoparticle reaches a cancer tumor it encounters an acidic solution which changes the platinum to it's toxic state, in which it can kill cancer cells.
Using polymer nanoparticles to deliver a molecule called JSI-124 to cancer tumors. This molecule degrades the ability of the cancer cells to suppress the immune system, possibly slowing the growth of cancer tumors.
Iron oxide nanoparticles can be used to improve MRI images of cancer tumors. The nanoparticle is coated with a peptide that binds to a cancer tumor. Once the nanoparticles are attached to the tumor, the magnetic property of the iron oxide enhances the images from the Magnetic Resonance Imagining scan.
Sensors based upon nanoparticles or nanowires can detect proteins related to specific types of cancer cells in blood samples. This could allow early detection of cancer. T2 Biosystems uses superparamagnetic nanoparticles that bind to the cancer indicating protein and cluster together. These clusters provide a magnetic resonance signal indicating the presence of the cancer related protein.