Feel the threat of tumors Deadly Nanobees

If the bees sting, they pump into their victims, a melittin peptide toxin called destroys cell membranes. Well, by encapsulating the molecule in an extremely strong nano researchers at Washington University School of Medicine in St. Louis, a possible new form of anti-cancer therapy with the potential to produce a wide range of tumor targets. This work was reported in the Journal of Clinical Investigation.

Samuel Wickline, MD, principal investigator of the Nanotechnology Center and the Siteman Cancer excellence, and his colleagues have developed their so-called toxic peptides such as melittin nanobees delivered specifically to cancer cells while sparing healthy cells, the result of chaos if not blind these molecules. "The fly in nanobees, landing on the cell surface, and place their cargo melittin, which is fast with target cells," said Dr. Wickline. "We have shown that the bee toxin is absorbed by the cells where it puts holes in their internal structures. "

Melittin was of particular interest to researchers because the mechanism by which it kills cells is unlikely that the bacteria develop resistance to conventional therapies often cause cancer. "Cancer cells grow and adapt to change resistance to many anti-cancer agents, the function of genes or DNA target using a cell, but it is difficult for the cell means bypass the mechanism of melittin can be found to kill "says co-author Paul Schlesinger, MD, Ph.D.

Scientists nanobees studied in two groups of mice with malignant tumors. A number of mice implanted with human cells of breast cancer, one with melanoma tumors. After four to five injections of melittin carriers of nanoparticles for several days, slowing the growth of breast tumors by nearly 25%, and size of melanoma tumors was reduced by 88% compared to untreated tumors.

The researchers found that the nanobees accumulated in solid tumors, because the nanoparticles are small enough to avoid the leakage of blood vessels surrounding the tumors. Researchers have developed a nanobee the objectives of active tumor. In addition, they adorned the nanobees with a molecule that binds to the integrin αvβ3, which on the surface of newly formed blood vessels, which can be found sprouting in the early stages of tumor development. Researchers hope that by targeting a process that begins when a tumor is small, their nanobees could be more effective against the cancer early. In fact, reduced injection targeted nanobees the extent of the proliferation of precancerous cells in the skin of mice by 80%.

In addition, the therapeutic potential of their shows nanobee formulations, researchers have also shown that the encapsulation of nanoparticles has been essential to the creation of an anti-tumor with appropriate safety and pharmacological properties. Significant amounts of melittin injection directly into the bloodstream produces widespread destruction of red blood cells. However spared encapsulation of nanoparticles into red blood cells and other tissues against damage in mice treated nanoparticles normal blood counts and tests were negative for the presence of blood-borne enzymes organ damage.

The nanobees also melittin protein degrading enzymes protected, that the body produces. Although melittin has been released from the circulation within minutes, half of melittin has been removed nanobees later, still in circulation, 200 minutes, enough to run through a mouse 200 times, this nanobees find enough time to tumors.

"Melittin a workaholic," said Dr. Wickline, "It is very stable on the nanoparticle, and it is easy and inexpensive to produce. We are now part of the melittin molecule non-toxic to other drugs hooks The targeting agent or compound imaging with nanoparticles.

The core of the perfluorocarbon is nanobee all, an inert compound used in artificial blood. The Task Force developed perfluorocarbon nanoparticles few years ago and has been studying their use in various medical applications, including diagnosis and treatment of atherosclerosis and cancer. "We can add our melittin nanoparticles having reported being built," said Dr. Wickline. "If we nanoparticles developed as carrier and give them a specific agent, we can then still a number of components using native melittin or melittin-like proteins, without the need to build the new institution. Melittin is Fortunately, the nanoparticles rapidly and completely rest on nanobee to contact the cell is made. "

This work, providing that in the newspaper "molecular targeted nanocarriers the cytolytic peptide melittin is specifically detailed on tumor cells in mice, therefore, tumor growth was supported by the NCI Alliance for Nanotechnology in Cancer, a comprehensive initiative to accelerate support nanotechnology demand for prevention, diagnosis and treatment of cancer