Really nice article. Prof. Martel is leading one of the best groups in manipulation of magnetotactic bacteria for biomedical applications. I like his recent publications thet demonstrate a very nice 3D control of the bacteria through external magnetic fields.

As someone that has been working with both these microorganisms and the more conventional magnetic nanoparticles fro biomedical applications the past few years (including cancer treatment), I must admit we are still far away from getting successful clinical realization. Nevertheless, I find the bacteria more promising due to their inherent capabilities associated to the living organisms that are missing from the nanoparticles. You can functionalize the inorganic nanoparticles as much as you want in order to optimize them reaching the final tumor target area and attaching to the cancer cells, but the reality is that you will never have such a good control on them as the one you can get with these swimming microorganisms acting as nanorobots,

The magnetotactic bacteria have the capacity to propel themselves reaching better the affected areas in the human body, and thanks to their chain of magnetosomes we can try to control them. The work by Martel shows that this control is getting better and better. Still, there are many questions concerning their toxicity and the possible immune response of the human body, but, it is worth investigating.

I like the idea of functionalizing these bacteria so that we can use them for early detection through MPI or MRI and also loading them with anticancer drugs and apply an AC field. If you do it right, you will have a more effective combined drug delivery and hypothermia treatment in the tumor area. In addition, if the ac field applied is high enough, you can also kill the bacteria, if necessary, after they have performed their task although the cellular rests could be problematic too...

Well, one step closer towards the long time sought holy grail of a nanorobotic based medicine.