Israeli biologist Ido Bachalet is part of the Harvard team that designed a microscopic machine of DNA nano-robots that can carry anti-bodies direct to tumours. First they make a basket-shaped truck, then add the payload which is released when the truck meets the key of the tumour.
http://israel21c.org/health/nanobot-truck-delivers-lifesaving-cargo/
http://www.nature.com/news/dna-robot-could-kill-cancer-cells-1.10047