Non-collageneous proteins influence bone crystal size and morphology: A SAXS study

Bone is a complex hierarchical natural composite. Its ability to accumulate damage and avert catastrophic failure is determined in part by its quality that is dependent on factors like bone material quality, bone micro-architecture and bone turnover. The hierarchy of bone, which ranges six orders of magnitude, also contributes significantly to toughening its matrix. Recently, non-collageneous proteins (NCP) have come to light as structural elements in bone's extracellular matrix. Apart from their structural role, it has been well studied that NCPs including osteocalcin (OC) and osteopontin (OPN) regulate the process of mineralization and crystal growth. Their deletion form the matrix is likely to alter crystal formation and growth processes and hence modify mineral organization at the ultrastructural level. Using small angle x-ray scattering (SAXS), this study aims at identifying how NCPs alter bone crystal structure and organization.