Aug. 24, 2009 -- A bee stings by pumping venom into its target and now scientists have borrowed the main ingredient in bee venom to seek and destroy tumor cells.
The researchers at Washington University in St. Louis deliver the venom on so-called nanobees, or tiny particles tipped with melittin (the main component of bee venom).
The nanoparticles have fewer side effects than conventional cancer treatments in mouse tests.
"This is more than a bee sting; if we injected this amount of free melittin [the main component of been venom] into mice it would make them very sick and might even kill them," said Paul Schlesinger, a co-author on the paper which appears in the Journal of Clinical Investigation.
"By using the nanobees we have limited the side effects and increased the effectiveness of melittin in mice," in fighting cancer.
When the average honeybee stings someone they inject a cocktail of drugs, including melittin. Around the sting melittin begins to rip cells apart, puncturing cell membranes and causing pain and inflammation.
Related Content:
Melittin anchored to a nanoparticle made from a material similar to Teflon acts very differently, however. Instead of attacking every cell, the melittin-anchored nanoparticles attack only cells that have one particular protein on their surface.
That protein helps tumor cells grow new blood vessels to feed them, and is found only on tumor cells.
When the nanoparticle finds a tumor cell it injects the melittin through the cell wall and into the cell itself. The melittin then finds mitochondria, a structure inside the cell that provides most of the power to cell, and destroys them.
"It doesn't cause inflammation, it doesn't cause antibodies to form," said Schlesinger. "It just destroys the mitochondria." As the mitochondria dies, so do the tumor cells.
Using mice, scientist tested the nanobees on two different types of cancer, melanoma and breast cancer.
After less than a week, the growth of human breast cancer cells in the mice had slowed by about 25 percent. For mice with melanoma, their tumors shrank by 88 percent.
Nanobees could also prevent, or at least postpone, cancer.
Infection with the human papillomavirus virus or having a mutation on the BRAC gene makes a person more likely to develop cervical or breast cancer, respectively. Regular injections of nanobees could help destroy tumor cells before they develop into full fledged and life threatening cancer.
"Instead of getting cancer at 26, a person might not get it until they were 66," said Schlesinger.
The nanobees can be tipped with hundreds of various cancer-killing or suppressing compounds, not just melittin. Whatever chemical is attached to the nanobees, the tiny particles are helping to solve one of the biggest problems in cancer treatment: drug delivery, says Chad Mirkin, a nanotechnology researcher at Northwestern University.
"We have lots of agents that can kill cells and kill them very well," said Mirkin. "But we need a way to deliver those agents to move around the body and deliver a payload [to tumor cells] with minimal damage to healthy cells."
Related Links:
our sites
video
mobile
shop
stay connected
corporate
