Nanomechanical Stethoscope

About

Summary: The cell is the smallest unit of the human body that is capable of independent life. Humans are a community of individual cells, and each cell contributes to maintaining a sustainable environment for the community. Very accurate control of pH, temperature, ionic concentrations, and gene transcription is maintained as the cell is subjected to a wide variety of stimuli. The cell is continually responding to various extra- or intra-cellular stimuli and maintaining internal balance through very complex biochemical pathways. These pathways are only starting to be completely understood.An important interface between cells and their environment is the cell membrane or the cell wall. It is through this dynamic junction that all drugs, biochemicals, ions and cellular signals must pass. The importance of understanding and monitoring these processes are of utmost importance to scientists studying the cell and cellular response to new drugs and/or environmental stimuli.To date there has been little evidence that a cells wall movement is connected to the status of the cells internal and/or external environment. In addition, other fields such as cytology, cellular pathology, and histology that study cell health typically require biochemical essays, sample preparation and surgical methods. These processes take time. A safe, fast, and cost effective cell monitoring method, which can be carried out in real-time would be a valuable tool for the medical research and health care community.    Innovation: UCLA's invention relates to a different approach to single cell analysis and does not require an optical or electron microscope. The invention relies on the motion of the cell wall. Similarly to the heart muscle cells known as cardiomyocytes, UCLA researchers have discovered the cell wall pulsations rhythmically just like the beating of the heart muscle cells.The cells wall pulsations can be monitored with an Atomic Force Microscope (AFM). The AFM provides very high special resolution (sub angstrom) and can be operated in a liquid environment. This high-resolution measurement capability in a liquid environment is critical for biological systems because key parameters such as temperature, pH, and ionic strength can be controlled and varied while the cell is kept alive. The impact of varying these parameters or a comparison with a control cells pulsations can be easily monitored with UCLA's invention. The AFM measurements can give an indication of the general health of the cell.    Development: The AFM has been used to contrast the signals from living, dead and osmotically shocked wild-type Saccharomyces cerevisiae (yeast cells). The living cell wall displacement is dramatically different from the dead cell. Once the cell wall movement is translated into the frequency domain the living and stressed cells vibrational spectra are significantly different. The potential exists to use these signals to identify the state of the cell and the impact of environmental stimuli on the cell.