Betterhumans is reporting on progress of scientists at USC in combining several nanoscale technologies (transferrin based transport vehicles with small interfering RNA segments (siRNAs)) to effectively combat cancer, in this case Ewing's sarcoma, a type of cancer which impacts children. Interfering RNAs are small RNA strands which preferentially bind to complementary messenger RNA (mRNA). This activates cellular processes, presumably evolved to defend against double stranded RNA viruses, that destroy the double stranded RNA effectively reducing or eliminating the activity of the protein normally produced by the specific mRNA targeted by the siRNA.
The article with links to background information is here. There is significant potential for using this type of therapy to combat other types of cancer where the overexpression of a specific gene or protein is the primary cause of the disease.
While this is not diamondoid molecular nanotechnology it it can legitimately be considered molecular nanotechnology because it is nanoscale, it is based on precision activity at the nanoscale level and takes advantage of molecular processes and machinery normally found in cells.