It is being done https://en.wikipedia.org/wiki/Monoclonal_antibody_therapy https://en.wikipedia.org/wiki/Monoclonal_antibody_therapy Often these drugs are very

It is being done https://en.wikipedia.org/wiki/Monoclonal_antibody_therapy https://en.wikipedia.org/wiki/Monoclonal_antibody_therapy Often these drugs are very expensive, and the targeting is to a specific receptor rather than a specific region. A magnetically or swim steered drug delivery would be for targeting a specific region/ location in the body, or perhaps to move into areas that are hard or slow to move into with simple diffusion.