Nanotechnology Kills Cancer Tumors in Mice
03 November, 2005 00:32 GMT
Harvard and MIT researchers have tested a technology in mice that may lead to a new approach to treating cancer. It involves a nanoparticle made of a hydrogen and carbon polymer with bits of drug bound up in its fabric and attached to a substance that homes in on cancer cells. The polymer gradually dissolves, exposing the nuggets of drug little by little. Experiments on mice have shown promise for the future of nanotechnology in treating cancer -- research that could bring doctors a step closer to using the technology to release cancer-killing drugs inside tumors while leaving the rest of the body unscathed.
After seeing how some mice were cured of human prostate cancer with the technology, cancer specialists at the European Cancer Conference in Paris said Tuesday they had high hopes for its future application.
"There are a lot of candidates for intelligent carriers and these nanoparticles are among them," said Dr. Gordon McVie, a professor at the European Institute of Oncology in Milan, Italy, who was not involved with the research.
'Looks Like a Step Forward'
Dr. David Kerr, a professor of clinical pharmacology and cancer therapeutics at Oxford University in England who also was not connected with the research, said the approach may have the edge on others. Previous designs of nanoparticles have used antibodies to zone in on cancer cells.
"The body's immunodefense system can create antibodies to the therapeutic antibodies, deactivate them and prevent the antibody binding to the right cancer cells. This looks like a step forward," Kerr said.
The study, done by scientists at Harvard Medical School and the Massachusetts Institute of Technology, involved engineering nanoparticles embedded with the cancer drug Taxotere. The particles were then injected into human tumors created from prostate cancer cell lines and implanted into the flanks of mice. The mice were watched for 100 days.
The technology being tested involves a nanoparticle made of a hydrogen and carbon polymer with bits of drug bound up in its fabric and attached to a substance that homes in on cancer cells. The polymer gradually dissolves, exposing the nuggets of drug little by little.
'The Tumor Completely Disappeared'
The mice were divided into five groups, including one that had their tumors injected with ineffective salt water. A second group died after injections of a nanoparticle containing no drugs.
Another group was given one shot of the drug, experienced an initial decrease in tumor size and then suffered a strong rebound. They also died.
Other mice were injected with a nanoparticle-encased drug, but one that was not designed to specifically target cancer cells.
"What happens here is the lymphatic system of the tumor can take it up and wash it away, because the nanoparticle is not targeted to the cancer cells," said the study's presenter, Dr. Omid Farokhzad of Harvard Medical School. The tumor initially shrank to half its original size, but then rebounded.
In a final group of mice, scientists injected the targeted nanoparticles containing the drug.
"The tumor completely disappeared," Farokhzad said.
Source: DailyNewsCentral.com |
