Hi Tricia, i ask because i thought the same as you but I work at a research hospital for cancer patients and when i was discussing my thoughts to one of the scientists he recognized my fear and asked his wife to explain to me. She is a molecular biology professor at a major university where i live. nano is a size like milimeter or centimeter it is not an entity. mRNA is very small and fragile and must be carried in to our cell in a nano-sized lipid or fat cell to protect it. mRNA is not new to the cancer treatment world. the new part about it is that we are using it as a vehicle to carry a code to our cell to create a spike protein instead of immune therapy for a cancer patient. this form of transport has not been done before in a vaccine. thats the new part. that being said basically the messenge sent is a recipe for our cell to make the spike protein which our body recognizes as foreign so it creates antibodies to attack the foreign substance. https://youtu.be/mvA9gs5gxNY