Cells are in a constant state of motion, shaping and reshaping themselves to form living organisms. Whether dividing, healing wounds, or building tissues, these microscopic movements depend on chemical signals that coordinate precise mechanical actions. Scientists have recently taken control of these processes using light, paving the way for programmable synthetic cells.
Living organisms, from bacteria to humans, rely on cellular shape changes for survival. These transformations are powered by a complex interaction between chemical signals and internal muscle-like fibers. This process, known as chemo-mechanical signaling, is responsible for crucial biological functions, including embryonic development and tissue repair. However, studying these intricate processes has been challenging, as researchers need a way to control the timing and strength of chemical signals inside cells. To address this, scientists have turned to optogenetics—a technique that uses light to manipulate biological functions.
A team of researchers, led by physicist Nikta Fakhri, used optogenetics to control how cells move and change shape. They focused on starfish egg cells, which naturally undergo surface contraction waves—a key process in early cell division. Normally, these waves are triggered by interactions between Rho proteins and GEF enzymes, leading to contractions in the cell’s outer layer. To gain precise control over this system, researchers engineered a light-sensitive version of GEF. By injecting genetic instructions for this modified enzyme into starfish eggs, they made the cells responsive to light.
Under a microscope, scientists directed beams of light onto specific parts of the cells. The light activated the engineered GEF enzyme, which in turn triggered Rho proteins to induce contractions. This allowed researchers to control cell movements with remarkable accuracy. They could create small pinches, sweeping waves, or even reshape cells entirely. Some cells, typically round, were manipulated into square shapes, showcasing the technique’s precision.
Beyond manipulating cell behavior, the researchers developed a mathematical model to predict how cells would react to different light patterns. This model helps map out possible cellular responses, shedding light on how cells self-organize and respond to external stimuli. Understanding these principles could improve medical applications, such as enhancing wound healing or designing synthetic cells for targeted drug delivery.
The implications of this research are vast. By mastering how cells move and respond to signals, scientists are one step closer to creating synthetic cells that function in specific ways, such as aiding tissue regeneration or delivering medicine with pinpoint accuracy. This breakthrough in optogenetics bridges biology and technology, offering exciting possibilities for future medical and biotechnological advancements.
