HRTEM Study of the Mineral Phases in Human Cortical Bone

Abstract

Although bone minerals have been widely studied by various techniques in previous studies, crystal structures and morphology of bone minerals remained as controversy. In this study, bone minerals were extracted from human cortical bone with ethylenediamine tetraacetic acid solution (pH 7.4, ambient temperature) and examined by high‐resolution transmission electron microscopy. The results showed that the majority of bone minerals were flake‐like and a few were needle‐like. Most of flake‐like minerals were less than 100 nm in their largest dimension and the needle‐like minerals have a width of ∼10 nm. Hydroxyapatite structure was identified in relatively thick bone minerals. However, octacalcium phosphate structure was identified in relatively thin flake‐like bone minerals. Moreover, central dark line defect similar to that reported in dentin and enamel crystals was observed in some of needle‐like bone minerals.

Ultrafine heat-induced structural perturbations of bone mineral at the individual nanocrystal level

“…In high resolution mode, it allows reaching sub-angstrom resolution [13] and therefore provides atomic details of the crystals. This increased resolution comes at the cost of the image field of view, which may not provide representative results due to the tissue heterogeneity.…”

Instructive composites for bone regeneration

“…[315] Using CR (Figure 1b) we observed that the spectrum of the synthesized apatite contained all the characteristic vibrational bands for a calcium phosphate apatite, and chemical similarity with bone mineral was seen (see also (Figure 1c), and such size is similar to that of needle-like apatite observed in human cortical bone. [23] Interplanar spacing (i.e. the d-value) in the synthesized apatite has been estimated with FFT-HRTEM as 7.85±0.39 Å (Figure 1d) that is close to the typical values recorded for synthetic hydroxyapatite.…”

“…It is interesting that other investigations reported that human cortical bone apatite has mainly flake-like morphology (30-100 nm length) but needle-like minerals (over 100 nm length and larger than 10 nm) were observed as well. [23] The Ca/P ratio of unsintered apatite, characterized by EDX, …”

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Improving the bone forming ability of synthetic bone substitutes using trace element additions

“…Bone is a complex nano-matrix system consisting of an organic framework of mainly type-I collagen fibrils in which small inorganic prism-shaped carbonated hydroxyapatite crystals (2-50 nm) are evenly embedded [222][223][224]. Because of their chemical similarity to bone mineral, calcium phosphate ceramics are considered the most promising materials for bone replacement [82].…”