Kinetic characterization of the deproteinization of trabecular and cortical bovine femur bones

•This work is focused on the kinetics of the in vitro deproteinization of bone.•Trabecular and cortical bones were deproteinized with 6% NaOCl (37, 50, 60 °C).•Trabecular bone deproteinizes faster than cortical, as expected.•However, trabecular bone requires more energy to start deproteinization.•Results are discussed considering structural/molecular differences in these bones.

The present study proposes an interpretation of the mechanism of bone deproteinization. Cortical and trabecular bovine femur bones were deproteinized using 6% NaOCl (37, 50, 60 °C). The kinetic parameters (rate constant and activation energy) were calculated, and the surface area of each type of bone was considered. A statistical analysis of the rate constants shows that cortical bone deproteinizes at a lower rate than trabecular. The activation energy is higher for trabecular than cortical bone, and no significant differences are found in the protein concentration values for both bones. Therefore, although trabecular bone deproteinizes at a higher rate than cortical, trabecular bone requires more energy for the deproteinization reaction to take place. Considering that both types of bones are constituted by mineral, protein, and water; the present work shows that the individual inner matrix architecture of trabecular and cortical bones, along with characteristics such as the mineral concentration and its bonding with collagen fibers, may be the responsible factors that control protein depletion.

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