In an earlier posting, we discussed the advances in the treatment of cancer by nanomedicine. A recent article by Neelesh R. Soman and other researchers at the Washington University School of Medicine in St. Louis and published online by the Journal of Clinical investigation describes and discusses what the authors refer to as
a new paradigm for targeted delivery . . . of problematic classes of cell-penetrating peptides to kill cancer cells both in vitro and in vivo.
The Article describes how the researchers created targeted nanostructures to deliver melittin, a toxin found in bees and usually transmitted to humans and other creatures via the stinger, leading to the nanostructures being dubbed "nanobees" in the university’s press release.
As experiments with mice demonstrated, the nanobees had a dramatic effect on breast cancer cells, slowing growth by up to 25%, and on melanoma tumors, decreasing their size by up to 88%. Nanobees that never reached their targets accumulated in the spleen and liver, then passing harmlessly out of the body.
While the nanobees are effective in treating cancer, the usual side effects of chemotherapy or radiation therapy weren’t noted:
. . . we observe a dramatic lack of toxicity with melittin-loaded nanoparticles in our mouse studies in terms of changes in serum electrolytes, serum enzymes, or body weights even after repeated injections (total 7) at doses 4 times the LD of free melittin.
As the authors note:
Perfluorocarbon nanoparticles thus represent the first in a class of unique lipid-based delivery vehicles for melittin and other cytolytic peptides with broad spectrum and multimodal antivascular and antitumor actions that could be exploited for anticancer therapy.