liposomes
Snapshots of Life: A Flare for the Dramatic
Posted on by Dr. Francis Collins
Credit: Valentin Romanov, University of Utah, Salt Lake City
Oil and water may not mix, but under the right conditions—like those in the photo above—it can sure produce some interesting science that resembles art. You’re looking at a water droplet suspended in an emulsion of olive oil (black and purple) and lipids, molecules that serve as the building blocks of cell membranes. Each lipid has been tagged with a red fluorescent marker, and what look like red and yellow flames are the markers reacting to a beam of UV light. Their glow shows the lipids sticking to the surface of the water droplet, which will soon engulf the droplet to form a single lipid bilayer, which can later be transformed into a lipid bilayer that closely resembles a cell membrane. Scientists use these bubbles, called liposomes, as artificial cells for a variety of research purposes.
In this case, the purpose is structural biology studies. Valentin Romanov, the graduate student at the University of Utah, Salt Lake City, who snapped the image, creates liposomes to study proteins that help cells multiply. By encapsulating and letting the proteins interact with lipids in the artificial cell membrane, Romanov and his colleagues in the NIH-supported labs of Bruce Gale at the University of Utah and Adam Frost at the University of California, San Francisco, can freeze and capture their changing 3D structures at various points in the cell division process with high-resolution imaging techniques. These snapshots will help the researchers to understand in finer detail how the proteins work and perhaps to design drugs to manipulate their functions.
Creative Minds: Targeting Cancer with Lasers and Nanoballoons
Posted on by Dr. Francis Collins
Jonathan Lovell
Photo by Douglas Levere
When most people think about cancer treatments, what typically come to mind are the side effects of traditional chemotherapy: cardiac, liver, and renal toxicity; hair loss; nausea; fatigue—just to name a few. These side effects occur because the cancer drugs damage not just cancer cells, but healthy cells as well. “Targeted” cancer therapy, on the other hand, is designed to target just the cancer cells. Some targeted therapies achieve this because they only attack cells with a particular molecular signature; others are directed to the cancer by physical means. Today, I’d like to introduce you to a researcher who’s developing a targeted drug delivery strategy that uses lasers and light activated drug delivery to fight cancer.
Jonathan Lovell, a Canadian-born researcher at the State University of New York at Buffalo (UB) and recipient of the NIH Director’s Early Independence Award, has designed unique nanosized spherical pods—1/1000 the diameter of a human hair—that open when light shines on them and snap shut in the dark. Lovell will fill these pods, also known as liposomes—hollow fat droplets—with anti-cancer drugs. He’ll then inject them into the body, where they’ll circulate, safely and silently: until they’re activated. When Lovell shines a red laser on the tumor, the light triggers the balloons to open and deliver a blast of the drug—only where it is needed. (Red light penetrates human tissue better than other colors.) It’s a terrific example of how bioengineering can bring fresh solutions to longstanding medical challenges.
