Tiny and swift, viruses are hard to capture on video. Now researchers at Princeton University have achieved an unprecedented look at a virus-like particle as it tries to break into and infect a cell. The technique they developed could help scientists learn more about how to deliver drugs via nanoparticles which are about the same size as viruses as well as how to prevent viral infection from occurring.
The video reveals a virus-like particle zipping around in a rapid, erratic manner until it encounters a cell, bounces and skids along the surface, and either lifts offagain or, in much less time than it takes to blink an eye, slips into the cell's interior. The work was published in Nature Nanotechnology.
"The challenge in imaging these events is that viruses and nanoparticles are small and fast, while cells are relatively large and immobile," said Kevin Welsher, a postdoctoral researcher in Princeton's Department of Chemistry and first author on the study. "That has made it very hard to capture these interactions."
The problem can be compared to shooting video of a hummingbird as it roams around a vast garden, said Haw Yang, associate professor of chemistry and Welsher's adviser. Focus the camera on the fast-moving hummingbird, and the background will be blurred. Focus on the background, and the bird will be blurred.
The researchers solved the problem by using two cameras, one that locked onto the virus-like nanoparticle and followed it faithfully, and another that filmed the cell and surrounding environment.
Putting the two images together yielded a level of detail about the movement of nano-sized particles that has never before been achieved, Yang said. Prior to this work, he said, the only way to see small objects at a similar resolution was to use a technique called electron microscopy, which requires killing the cell.
"What Kevin has done that is really different is that he can capture a thr
|Contact: Catherine Zandonella|