Raman imaging as a probe of chemical and biomechanical properties of bone tissue

Raman microspectroscopy and imaging can be used to probe the chemical properties of newly mineralized bone tissue. In this study, our early mineralization models are neonatal murine cranial suture tissue and prostate cancer cell cultures. The murine cranial tissue was harvested from animals three weeks postnatal. On this time scale, remodeling does not corrupt the temporal record inherent in the spatial distribution of mineral species. When analyzing transects, line images, of the cranial tissue, multivariate data processing is required to generate chemical state plots from the hundreds of Raman spectra acquired during a single transect experiment. In most cranial tissue specimens more than one phosphate mineral environment is observed, allowing inferences on the relation between chemical structure and physiologically important properties. The prostate cancer cell cultures were cultured for up to nine days. Point microspectroscopy reveals the ratios of mineral species present and the amount of protein species in the cell cultures changes dramatically over the course of 9 days. Very low carbonation, typical of early-mineralized tissue, is observed in both of these models.