Deep-ultraviolet Raman spectroscopy study of the effect of aging on human cortical bone

The age-related deterioration in bone quality and consequent increase in fracture incidence is an obvious health concern that is becoming increasingly significant as the population ages. Raman spectroscopy with deep-ultraviolet excitation (244 nm) is used to measure vibrational spectra from human cortical bone obtained from donors over a wide age range (34-99 years). The UV Raman technique avoids the fluorescence background usually found with visible and near-infrared excitation and, due to resonance Raman effects, is particularly sensitive to the organic component of bone. Spectral changes in the amide I band at 1640 cm(-1) are found to correlate with both donor age and with previously reported fracture toughness data obtained from the same specimens. These results are discussed in the context of possible changes in collagen cross-linking chemistry as a function of age, and are deemed important to further our understanding of the changes in the organic component of the bone matrix with aging.