An in vitro investigation of cell injury mechanisms due to mechanical impact

Cell injuries associated with rapid mechanical load have garnered a great attention in the scopes of mechanisms of traumatic brain injury, development of reliable injury criteria, and accurate prediction of traumatic damage. We present an innovative experimental protocol that enables applications of well-controlled and repeatable acceleration-induced pressure gradients to live cells by utilizing both a drop tower system and environmentally controlled live-cell microscopy. This platform is capable of in-depth observations of individual cells and cell populations, required to reveal cell injury mechanisms at the single level while monitoring population-level cell responses, e.g., cell viability and membrane damage. Our study shows acceleration-induced cavitation is the main mechanism of cell injury and death rather than the linear acceleration itself. This result may indicate that linear acceleration, an overlooked mechanism for brain injury, must be appropriately considered due to the possibility of cavitation-induced damages.