Synchrotron FTIR microspectroscopy for quantitative assessment of collagen mineralization: a comparative analytical study

Abstract

This study employs synchrotron Fourier transform infrared (SR-FTIR) microspectroscopy to comparatively assess structural changes in wet-spun collagen fibers mineralized by three methods: polymer-induced liquid precursor (PILP), in situ precipitation, and hydroxyapatite mineral addition (H.A.M.A.). Spectroscopic analysis revealed method-dependent protein structural perturbations, with PILP and in situ methods showing minor amide I perturbations (<= 4 cm(-)1) (1656-1658 cm(-)1) while H.A.M.A. induced shifts to 1650 cm(-)1. Mineral quality assessment via Ca/PO4 peak ratios and mineral-to-organic ratios (0.21-0.32) distinguished between approaches. PILP mineralization exhibited minimal structural disruption with the highest Ca/PO4 ratios, whereas H.A.M.A. achieved maximum mineral loading (MTO = 0.32) with greater structural alteration. These analytical findings establish spectroscopic markers correlating mineralization pathway with collagen structural integrity and mineral composition.