TECHNOLOGY FOR CHANGE

Better Drug Delivery with Nanoparticles

Rebecca Kutzer-Rice | Date: 07-23-10 | Comments

Using nanotechnology, researchers at the University of Rhode Island have developed a new drug delivery system that could lead to more precise and effective treatments.

A team of chemical engineers the University of Rhode Island has developed a method of delivering pharmaceutical drugs directly to infected cancer cells, rather than all cells of the body. The delivery method works by embedding nano-sized molecules of drugs inside liposomes, nanoscale bubbles made of lipids. While drug delivery via liposomes has been in use for several decades, the researchers made an important change to the technology by adding iron oxide nanoparticles to the lipid structure. When activated by non-invasive electromagnetic fields, the iron oxide causes the lipid shell to leak�thus releasing the drug.

"We've shown that we can control the rate and extent of the release of a model drug molecule by varying the nanoparticle loading and the magnetic field strength," states Geoferry Bothun, a professor at the University of Rhode Island. "We get a quick release of the drug with magnetic field heating in a matter of 30 to 40 minutes, and without heating there is minimal spontaneous leakage of the drug from the liposome."

The structure is relatively easy to make because of the unique natural properties of the particles. While lipids are hydrophobic�they repel water�most drug particles are hydrophilic�they attract it. The lipids and iron oxide particles self-assemble into a protective shell around the drugs.

The prospect of direct delivery is especially important for cancer drugs, which wreak havoc on the body by indiscriminately attacking all cells�not just the cancerous ones. The next step will be developing liposomes designed to target specific cancer cells.

"Any ability to target the drug is better than a drug that goes everywhere in your system and generates off-target effects," says Bothun. "If you can get an assembly to a targeted site without losing its contents in the process, that's the holy grail."

Other researchers included Arijit Bose and graduate student Yanjing Chen. Their results were published in the June issue of American Chemical Society Nano.