Targeting cancer cells in the human body isn't entirely accurate because the treatments that are commonly used, chemotherapy and radiotherapy, are distributed across the entire body. So, for instance, like when you take a headache tablet, the drug travels through the bloodstream and so is diluted along the way.
It's the same for something like chemotherapy, meaning the entirety of the drugs that can destroy the cancer cells don't get to the tumor. It also means that there are huge side effects too, like the overwhelming feelings of sickness and queasiness, hair loss, etc.
Treatments like immunotherapy are addressing this problem by better targeting the cancer cells, but a new breakthrough could be the most effective delivery method yet.
Recently Canadian scientists from the McGill University, Université de Montréal, and Polytechnique Montréal have published their research that uses nanorobots that travel through the bloodstream and deliver cancer-killing drugs directly to the cancer cells. It means that, unlike chemotherapy, healthy cells and organs won't be affected.
These nanorobots contain around 100 million bacteria which are full of drugs that destroy cancer cells. These can be injected into the body and then head on a path directly to the part of the body where the cancerous tumor is. They are propelled with enough force that they can travel effectively and enter the tumor at an adequate depth.
Once the nanorobots (which aren't robots in the machine sense but are collections of molecules that can deliver drugs) enter the tumor they can detect which areas have been exhausted of oxygen, called hypoxic zones, and deliver the drugs to them. Propagating tumor cells create these zones which have previously been resistant to most treatments, but not with this new delivery method.
The research has so far been successfully performed on mice, but it's hoped it could open up new ways to target cancer cells and assist treatment in humans. According to Science News Journal, "Prof. Martel [head of the research team] goes on to say that more advanced intervention methods and engineering concepts will be created as a result of the innovative use of these nanorobots. As well, the synthesis of new transportation methods for diagnosing, imaging and therapeutic agents can be further researched. Chemotherapy is a toxic form of therapy for the human body and as a result of the research the side effects could be eliminated while the therapeutic effectiveness is increased by using nanorobots to directly transport the drugs to the targeted area."