I have to leave, but in case anyone knows ... Do we have cancer-seeking nanoparticles with claws inside us?
Officially, no, not yet. However, in a manner of speaking, we do.
Our standard immune system is designed to seek out and destroy anything it recognizes as foreign to the body. "Recognizes as foreign" is the key.
For example, viruses can be mopped up as quickly as they appear if the immune system has had an opportunity to learn how to identify them. That's a process we call developing antibodies. The immune system also destroys human body cells that have developed recognizable dysfunction. Again, recognizable is key.
Perhaps our new abilities to interpret and sequence genes will allow us to tailor a response to new viruses as easily as a locksmith can re-key a lock. Perhaps not.
Of possibly more hope is that better understanding will allow us to fine-tune the immune system to more quickly and easily discover cancer cells and deal with them. Currently our most common treatments involve chemical or surgical attack against the cancer lesions.
Years ago a book referred to this as "the poison and the blade".
This gross mechanism is inadequate when the cancer metastasizes. What is needed at that point is an army of agents, seeking out the cancer cells one by one, just as the immune system operates against bacteria and viruses.
Researchers are studying how the immune system can be "trained" to do this.
Other researchers are working on a micro-scale version of the surgery mentioned above. Tiny robots, designed to mimic immune function cells, would have some manner of recognizing cancer cells, and then destroying them, perhaps by some form of nanometer-scale claw mechanism.
This has been a fond hope for more than thirty years, but it is not without promise. We are getting closer all the time.
If the question above comes from one of your bright and precocious children, you should encourage them to follow their curiosity into the medical research field. One of them may provide you a very special gift one day in the future, an injection that will do an extreme make-over on you from the inside.
On the other hand, considering what you know about their habits, you may wish to proceed very cautiously about accepting that gift.