i thought you were asking if the physics engine is able to simulate the inner workings of a cell? you are in the wrong forum! this forum is about questions related to the physics engine only...

your idea is no crackpot idea! you could make a fun game out of it and the ai of viruses shouldn't be a big problem! when i was a child i had a game like this for my home computer. it was based on the movie <the fantastic voyage>.