Monitored Steady State Excitation and Recovery (MSSER) radiation force imaging of engineered tissue constructs

Production of engineered bone tissue requires integration of synthetic and natural materials and ideal chemical and mechanical stimulation. More understanding of changes in mechanical properties of these tissues during differentiation is needed. Current tensile testing methods result in destruction of tissue constructs. A non-destructive testing method is desired. Monitor Steady State Excitation and Recovery, MSSER, an ultrasound imaging based elastography method, uses prolonged acoustic force to displace tissue while monitoring changes in strain during force application. MSSER, along with the underdamped harmonic oscillation model, was used to determine the elastic modulus of tissue constructs. Localized elastic modulus values were calculated using MSSER for tissue constructs grown in osteogenic and complete (non-osteogenic) growth media. Images showing elastic modulus values were produced. Validation of elastic modulus images were done performing calcium digestion on tissue constructs. MSSER hopes to provide a non-invasive testing method, allow for localized measurements, and aid in calcium detection