Nanobees deliver deadly sting
A group of scientists has harnessed the power of bee venom and used it to kill tumour cells in mice. By arming small particles dubbed nanobees with the bee venom melittin, they successfully delivered the toxin directly to tumours.
If administered in high enough concentrations, melittin can destroy any cell by punching holes in the cell membrane. This mechanism is useful in the treatment of cancer, as cells find it difficult to adapt to survive such an attack. The challenge was to administer the toxin in a targeted way, so it only affected the cancer cells. To do this, the team attached a targeting agent to the nanobee particles containing melittin. The agent targeted the proliferating blood vessels of tumours; rapidly growing tumours require a vast supply of blood.
The nanobees were tested on two groups of mice. One group had been implanted with human breast-cancer cells and the other had melanomas. After four to five injections, the breast tumours had reduced in size by a quarter, and the melanomas by nearly nine tenths, compared with untreated tumours. Despite the toxicity of melittin, the mice suffered from few side effects and there was little evidence of damage to non-cancerous cells. The carrier particles were harmlessly eliminated from the body by evaporation from the lungs after they had delivered the melittin to the tumours.
The flexibility of nanobees suggests they could be used in a range of medical situations. Further studies will investigate their use for other tumour types, and their potential for treating patients.