An Insight into the Structural Dependence of Amino Acids in Inducing Hydroxyapatite Mineralization

Investigating the effect of amino acids, which are the building blocks of proteins, in biomineralization is beneficial to provide deeper insight into the function that protein exerts in mineralization. In this work, we tethered different amino acids to a single layer of two-dimensional polymer so that the density and spatial dispersion of amino acids could be controlled, and we studied the structural dependence of amino acids in inducing hydroxyapatite (HAp) mineralizaion. FTIR, Raman, X-ray photoelectric spectroscopy, and scanning electron microscopy were utilized to explore the morphological characteristics, chemical components, and crystallinity of the mineral layers. The results demonstrated that aspartate had stronger effectiveness in mineralization compared with serine, which can be rationalized by the difference in carboxyl group density and surface potential between these two materials. Our strategy provides a possible path for the decoupling of complex influencing factors in biomimic mineralization so that it gives more detailed insight into the structure-performance relationship.