Towards the control of the biological identity of nanobiomaterials: impact of the structure of 011¯0 surface terminations of nanohydroxyapatite on the conformation of adsorbed proteins

ABSTRACT High-resolution transmission electron microscopy, ζ-potential and in-situ IR spectroscopy of adsorbed CO were combined for elucidating the ratio between { 01 1 ¯ 0 } _ Ca-rich: { 01 1 ¯ 0 } _ P-rich terminations of { 01 1 ¯ 0 } facets, i.e. the surfaces with the highest morphological importance, in two nanohydroxyapatite samples. Bovine serum albumin was found to form at least a monolayer on the surface left accessible to protein molecules by the agglomeration of nanoparticles when suspended in the buffered incubation medium. Noticeably, the conformation of adsorbed proteins appeared sensitive to the ratio between the two types of { 01 1 ¯ 0 } terminations, also resulting in a difference in the surface exposed toward the exterior by the adsorbed protein layer(s).