Research scientists from UC San Diego, UC Santa Barbara, and MIT have developed tiny lipid micelles, that they call nano container ships, that are capable of delivering both imaging agents and therapeutic drugs directly to strategic sites within the body, while avoiding an attack from the host’s immune system.
The researchers designed the hull of the ships to evade detection by constructing them of specially modified lipids–a primary component of the surface of natural cells. The lipids were modified in such a way as to enable them to circulate in the bloodstream for many hours before being eliminated. This was demonstrated by the researchers in a series of experiments with mice.
The researchers also designed the material of the hull to be strong enough to prevent accidental release of its cargo while circulating through the bloodstream. Tethered to the surface of the hull is a protein called F3, a molecule that sticks to cancer cells. Prepared in the laboratory of Erkki Ruoslahti, a cell biologist and professor at the Burnham Institute for Medical Research at UC Santa Barbara, F3 was engineered to specifically home in on tumor cell surfaces and then transport itself into their nuclei.
The researchers loaded their ships with three payloads before injecting them in the mice. Two types of nanoparticles, superparamagnetic iron oxide and fluorescent quantum dots, were placed in the ship’s cargo hold, along with the anti-cancer drug doxorubicin. The iron oxide nanoparticles allow the ships to show up in a Magnetic Resonance Imaging, or MRI, scan, while the quantum dots can be seen with another type of imaging tool, a fluorescence scanner.
“The fluorescence image provides higher resolution than MRI,” said Sailor. “One can imagine a surgeon identifying the specific location of a tumor in the body before surgery with an MRI scan, then using fluorescence imaging to find and remove all parts of the tumor during the operation.”
The team found to its surprise in its experiments that a single mother-ship can carry multiple iron oxide nanoparticles, which increases their brightness in the MRI image.
“The ability of these nanostructures to carry more than one superparamagnetic nanoparticle makes them easier to see by MRI, which should translate to earlier detection of smaller tumors,” said Sailor. “The fact that the ships can carry very dissimilar payloads—a magnetic nanoparticle, a fluorescent quantum dot, and a small molecule drug—was a real surprise.”
Press release: Researchers Develop Nano-Sized ‘Cargo Ships’ to Target and Destroy Tumors…
Images: Top: Photo of a vial of anti-cancer nano ships glows red under a black light.
A vial of anti-cancer nano ships glows red under a black light. The particles glow red because they contain fluorescent “quantum dot” nanoparticles. Side: The nanometer-sized cargo ships look individually like a chocolate-covered nut cluster, in which a biocompatible lipid forms the chocolate shell and magnetic nanoparticles, quantum dots and the drug doxorubicin are the nuts.
