Fourier Transform Infrared Spectroscopy of Bone Tissue: Bone Quality Assessment in Preclinical and Clinical Applications of Osteoporosis and Fragility Fracture

Abstract

The pathogenesis of bone fragility is of utmost importance especially to modern societies with aging populations. Increased skeletal fragility due to aging and disease motivates researchers to investigate the contributing biological mechanisms and to find ways to inhibit them. Bone quality is a set of structural and compositional variables that contribute to bone strength and influence its ability to resist fracture. They originate from multiple bone hierarchical levels and include the morphology (mass distribution), the chemical composition, and the biomechanical properties of bone tissue such as stiffness, fatigue strength, and fracture toughness. Qualitative and quantitative measurements of bone material properties reflect the underlying health or disease status. Fourier transform infrared (FTIR) spectroscopy and imaging are able to evaluate spatially inhomogeneous structures like bone in the form of sections or homogenized powder, providing simultaneous quantitative and qualitative information from both organic and inorganic tissue components. These techniques give a snapshot of structural and material properties that essentially depend on bone turnover while they are also sensitive to tissue alterations due to metabolic and nonmetabolic diseases, and external factors like administration of drugs. In this review, we discuss the application of FTIR spectroscopy and imaging to preclinical and clinical studies. The interpretation of results emphasizes the potential of infrared spectroscopic techniques to associate bone heterogeneity with fracture risk, assess the compositional and structural properties of osteoporotic bone, and investigate bisphosphonates’ antiresorptive action and side effects.