Using lasers to manipulate cell membranes

17 Jun 2002

An Israel-U.S. research team has discovered that lasers can cause artificial versions of cell membranes to expel inner objects as large as 3/4 their diameter. A cell membrane is made of lipid molecules that arrange themselves into a closed, sac-like structure (a vesicle) to prevent energetically unfavorable contact between water and the water-repelling lipid tails. For this reason, it's difficult to rip open a vesicle, let alone expel interior objects.

In the experiment, researchers focus a laser spot onto an artificial vesicle. The light's electric field pulls lipid into the spot. The light also causes some of the lipid inside the vesicle to break off into a suspension of smaller objects which escape the laser spot. To increase the entropy in the system, water rushes into the vesicle to disperse the smaller structures, driving out an inner object through a reclosable pore in the vesicle. Manipulating membranes with lasers may someday allow researchers to transform living cell membranes in desired ways.