The particles are described as having a nanoporous core with a high surface area and an encapsulating lipid bi-layer (liposome). The nanoparticles and the surrounding cell-like membranes formed from liposomes together become the combination referred to as a protocell: the membrane seals in the deadly cargo and is modified with molecules (peptides) that bind specifically to receptors overexpressed on the cancer cell's surface. (Too many receptors is one signal the cell is cancererous.) The nanoparticles provide stability to the supported membrane and contain and release the therapeutic cargo within the cell. The lipids also serve as a shield that restricts toxic chemotherapy drugs from leaking from the nanoparticle until the protocell binds to and takes hold within the cancer cell. This means that few poisons leak into the system of the human host, if the protocells find no cancer cells. This cloaking mitigates toxic side effects expected from conventional chemotherapy.
This method is currently being tested on human cells in vivo (occurring or carried out in a living organism) and will shortly be tested in mouse tumors. Estimates are that this method will be 10,000 times more effective than current liposome delivery methods and may be available in as early as 5 years. This will be the first work to show targetted delivery of nanoparticles to cancers supported in part by a grant from the National Cancer Institute's Alliance for Nanotechnology in Cancer .(1)
This method provides hope for easier treatment of some cancers. As well, the specific targetting that is being attempted will reduce the side effects of cancer treating drugs in the patient. This may lead to better long term health for the cancer survivor as well as less painful treatments.
1. Carlee E. Ashley, Eric C. Carnes, Genevieve K. Phillips, David Padilla, Paul N. Durfee, Page A. Brown, Tracey N. Hanna, Juewen Liu, Brandy Phillips, Mark B. Carter, Nick J. Carroll, Xingmao Jiang, Darren R. Dunphy, Cheryl L. Willman, Dimiter N. Petsev, Deborah G. Evans, Atul N. Parikh, Bryce Chackerian, Walker Wharton, David S. Peabody, C. Jeffrey Brinker. The targeted delivery of multicomponent cargos to cancer cells by nanoporous particle-supported lipid bilayers. Nature Materials, 2011