Well, my training is as a biochemist, not a doctor, but my understanding is that complete transfusions are extremely difficult or outright impossible (there are

Well, my training is as a biochemist, not a doctor, but my understanding is that complete transfusions are extremely difficult or outright impossible (there are a lot of tiny little capillaries for things to get stuck in...). Not to mention that the liver is really good at what it does, and it would probably have soaked up most everything by the time you got to the hospital. The real concern is not that it ends up in the liver, but that the plastic antibodies don't bind as tightly as a natural antibody so that, once in the liver, the toxins slowly "leak" out and poison the liver. Honestly, we've gotten really, really good at manufacturing antibodies against almost anything. Antibodies are a mainstay of modern biomedical research. Sure, they're expensive, but other than cost I don't see anything that plastic antibodies could do that natural antibody can't (and even in terms of cost, if you need one molecule of target to serve as the "stamp" for each plastic antibody, these are probably going to be more expensive since, once you've made the initial antibody, scaling up natural antibodies is mostly a solved problem.