title: Atomic force microscopy characterization of the external cortical bone surface in young and elderly women: potential nanostructural traces of periosteal bone apposition during aging.
abstract: On the basis of the suggestion that bone nanostructure bears “tissue age” information and may reflect surface deposition/modification processes, we performed nanoscale characterization of the external cortical bone surface at the femoral neck in women using atomic force microscopy (AFM). The specific aims were to assess age-related differences in bone nanostructure and explore the existence of nanostructural traces of potential bone apposition at this surface. Our findings revealed that the external cortical surface represents a continuous phase composed of densely packed mineral grains. Although the grains varied in size and shape, there was a domination of small grains indicative of freshly deposited bone (mean grain size: young, 35 nm; old, 37 nm; p > 0.05). Advanced quantitative analysis of surface morphological patterns revealed comparable roughness and complexity of the surface, suggesting a similar rate of mineral particle deposition at the surface in both groups. Calcium/phosphorus ratio, a measure of bone tissue age, was within the same range in both groups. In summary, our AFM analyses showed consistent nanostructural and compositional bone features, suggesting existence of new bone at the periosteal bone surface in both young and elderly women. Considering observed age-related increase in the neck diameter, AFM findings may support the theory of continuous bone apposition at the periosteal surface.
authors.affiliation: University of Belgrade, School of Medicine, Institute of Anatomy, Laboratory for Anthropology, 4/2 Dr Subotica, 11 000 Belgrade, Serbia.
authors.forename: Petar
authors.initials: P
authors.lastname: Milovanovic
authors.forename: Marija
authors.initials: M
authors.lastname: Djuric
authors.forename: Olivera
authors.initials: O
authors.lastname: Neskovic
authors.forename: Danijela
authors.initials: D
authors.lastname: Djonic
authors.forename: Jelena
authors.initials: J
authors.lastname: Potocnik
authors.forename: Slobodan
authors.initials: S
authors.lastname: Nikolic
authors.forename: Milovan
authors.initials: M
authors.lastname: Stoiljkovic
authors.forename: Vladimir
authors.initials: V
authors.lastname: Zivkovic
authors.forename: Zlatko
authors.initials: Z
authors.lastname: Rakocevic
mesh_terms: D000367:Age Factors; D000368:Aged; D000375:Aging; D002118:Calcium / Q000032:analysis; D005260:Female; D005269:Femur / Q000737:chemistry / Q000648:ultrastructure*; D006801:Humans; D018625:Microscopy, Atomic Force; D008903:Minerals / Q000032:analysis; D053758:Nanoparticles / Q000032:analysis; D010710:Phosphates / Q000032:analysis; D013499:Surface Properties
chemical_list: D008903:Minerals; D010710:Phosphates; D002118:Calcium