Influence of hydrochloric acid concentration on the demineralization of cortical bone

Abstract

a b s t r a c tAlthough demineralized bone matrix has been considered a successful grafting material, combining both osteoconductive and osteoinductive properties, conflicting results have been published in the literature regarding its bone-inducing abilities. This may be a consequence of following different demineralization procedures that naturally result in products with different properties.The present work examines the evaluation of the demineralization process of similar samples of human cortical bone using three different concentrations of hydrochloric acid solutions (0.6 M, 1.2 M and 2.4 M). Sample calcium content was determined (by Atomic Absorption Spectroscopy) at various immersion times, allowing the construction of the corresponding kinetic profiles. Phase and chemical composition were enabled by X-Ray Diffraction Spectroscopy and Fourier Transform Infrared Analysis, respectively. Structural modifications were followed by Light and Scanning Electron Microscopy and quantified by mercury porosimetry (in terms of porosity and pore size distribution).As expected, increasing the acid concentration led to an increase in the demineralization rate, but not in a proportional way. However, one of the most significant effects of the acid concentration was found on the sample structural features. In fact, a considerable increment in porosity was detected for the sample subjected to the highest hydrochloric acid concentration. Microscopic observations demonstrated that despite the structural deformation resultant from demineralization, the basic microstructure was preserved.

When size matters: differences in demineralized bone matrix particles affect collagen structure, mesenchymal stem cell behavior, and osteogenic potential

“…The first one was due to water evaporation of the main mass around 90°C which corresponds to an endothermic process. The second weight loss derived from the decomposition of collagen and other residual organic components . The third weight loss, above 800°C, matches mostly to the fraction of hydroxyapatite as the inorganic constituent.…”

“…The second weight loss derived from the decomposition of collagen and other residual organic components. 27 The third weight loss, above 8008C, matches mostly to the fraction of hydroxyapatite as the inorganic constituent. These results are evidence that the grinding of the bone damages the crystalline structure of the apatite while the collagen does not undergo significant change.…”

Characterization of Bone and Bone-Based Graft Materials Using FTIR Spectroscopy

“…FTIR has been used to monitor the bone demineralization process using HCl under different experimental conditions (acid concentrations and exposure times) (Figueiredo et al, 2011). Fig.…”

Osteoinductive PolyHIPE Foams as Injectable Bone Grafts

“…The demineralization process was adapted from Figueiredo et al 38 Long hind bones were extracted from the rats, rid of soft tissue using a scalpel and gauze, and the majority of marrow removed with water and compressed air. Bones were soaked in a 1:1 volume chloroform: methanol solution at 1 g bone to 30 mL solution for 3 h. After solvent treatment, bones were washed once with reverse osmosis water, placed in a 0.6 M HCl solution, and stirred for 24 h to decalcify.…”