<title>Early mineralization of normal and pathologic calvaria as revealed by Raman spectroscopy</title>

Abstract

Bone tissue consists of a carbonated apatite-like mineral supported on a hydrated, collagen-rich protein matrix. Despite extensive studies into the macroscopic characteristics of bone, much about the early stages of bone formation remains unknown. Raman microspectroscopy and imaging are increasingly important tools for the study of mineralized tissue, due to advancements in both spectral acquisition and analysis protocols. With this technique, mapping of both organic and inorganic components of bone, in addition to determining their distributions with high spatial resolution across a specimen, can be realized. We have employed Raman microscopy to investigate the early stages of mineralization in four different mouse calvarial systems: typical and atypical osteoblastic (bone forming) cell cultures and healthy and diseased bone tissue. These systems are commonly utilized as models for mineralization. The mineral deposited by osteoblast cultures grown atypically gives a Raman signal completely different to that observed in osteoblast cultures grown in the conventional manner. Similarly, Raman images of healthy and diseased bone tissue show differences in the relationship of the mineral and matrix environments. In this report, we compare the several differences between these four mineral environments, and discuss the chemistry of mineral maturation observed.