Impact of bone age and anatomy, and of collagen self-assembly, on the stability towards thermal unfolding and on the renaturation capacity of mineralized bovine bone collagen solutions and films – Improving valorisation through variability elucidation

Collagen is a structural protein with utmost biological and mechanical functions. Bovine bone is the first source of mineralised collagen, where the mineral fraction (calcium phosphates) confers it additional properties. Collagen was widely used in biomaterials and several avant-garde applications continue to be revealed. However, at a large scale, it is recovered from few and standardised sources, while the majority of the stream is lost. One of main reasons of this defeat is the bone variability with biological parameters, and the high collagen reactivity towards environmental stimuli. While these factors can hindrance bone valorisation and collagen application, if understood and harnessed, they allow the development of products that better meet expectations. Hence, this study aimed at the elucidation of the effect of the bovine bone age (young/adult) and anatomy (femur/tibia) on the conformation of collagen in mixture with calcium phosphates, on the collagen reactivity towards thermal unfolding (25 to 85°C) and on its ability to renature. The impact of collagen self-assembly (fibrils/capsules) and of collagen formulation (solution/film) was concomitantly evaluated. Synchrotron radiation circular dichroism spectroscopy was used, and samples variability was explored by chemometrics. The major clustering effect was imparted by the formulation, followed by bone anatomy and collagen self-assembly. This study is a pioneer approach in the elucidation of the impact of some biological and technological factors on collagen unfolding and renaturation. At same time, this research aims to highlight the importance of animal bones sorting to ensure collagen behaviour homogeneity, improved bones valorisation and more targeted applications.