In a major breakthrough, researchers of IIT-Jodhpur have designed special nanoparticles to fight cancer cells. Cancer cells develop drug resistance. Research was going on to find a way of killing cancer cells because cancer cells have developed ‘multi-drug resistance’ (MDR). This breakthrough would also be beneficial in treating several other diseases. The research team had taken lung cancer for their study.
Process of Killing Cancer Cells
As per the researchers, the best way to kill cancer cells is by oxidising them. Like any other cells, cancer cells accumulate oxygen when they die. Accumulation of oxygen happens when any molecule containing oxygen gets into the cell. Such oxygen-containing molecules damage the cells and are called reactive oxidative species (ROS) or free radicals. The oxygen in these free radicals reacts with many chemicals in the cells leading to the destruction of cells function and their death. This process is called oxidative stress. The purpose of consuming anti-oxidants is to remove free radicals or the ROS from our body.
Since cancer cells like any other cell naturally have a defence system, it was needed to demolish the anti-oxidative defence mechanism of the cancer cells. For this purpose, the researchers developed a special type of nanomaterial, called the ‘upconversion nanoparticles’ (UCNP), which is a combination of rare metals. When UCNPs absorb infrared light, they get energised and produce a significant amount of ROS. After that, the UCNP has to be made to get only into the cancer cells. So, the researchers zeroed in on a specific feature of lung cancer cells. Cancer cells are called ‘epidermal growth factor receptors’ (EGFRs). Just as spike proteins of the virus bind to the ACE2 receptor in the human cells to enter them in the SARS-CoV2 virus, similarly, EGFRs are receptors and they are over produced in the lung cancer cells.
In order to modify the UCNP to home in on the EGFR, the researchers attached the UCNP to a commercially available anti-EGFR antibody. The UCNP has a carboxyl group. [Carboxyl groups are made up of two functional groups attached to a single carbon atom, namely, hydroxyl, (single-bonded OH) and carbonyl, (double bonded carbon and oxygen atoms C=O.] The anti-EGFR antibody has an amine group. (Amines are compounds and functional groups that contain a basic nitrogen atom with a lone pair.) The carboxyl and amine join together to form a molecule that could enter the lung cancer cell through the EGFR. Thus, the anti-EGFR antibody leads the UCNP inside the cancer cells. Then, infrared radiation (IR) is shone on the cancer cells. The UCNP produces a huge quantity of ROS when nourished with IR. This process creates oxidative stress in the cancer cells and ultimately kill them.
Challenges Ahead
Since this treatment has been proven in a lab only, there are still some challenges in its practical application. It is also important to ascertain that UCNP does not prove to be toxic or have any other harmful side-effects.
Another challenge is to produce UCNP in large quantities. For the initial testing on mice, only a few milligrams of UCNP were adequate. However, for testing it on humans, several grams of UCNP would be required, though this might not be an impossible task.
Way Forward
Once validated in clinical trials, this method would take at least a few years to be declared as a cure for cancer. Initially, IIT-Jodhpur researchers have experimented this method with lung cancer cells only. However, this could be done for other types of cancers as well, when other nanoparticles which are similar to UCNP are found.
Apart from that, the UCNP method could also be used in diagnosis. The nanoparticles glow when lit with IR. Therefore, they could be a good biomarker to identify bad cells and a completely new field of diagnosis could come into being.
Not only that, this treatment pathway could also be extended to many diseases such as neurodegenerative disorders. This treatment pathway has also the potential to completely revolutionise the field of medicine in the time to come.
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