A facile method to in situ formation of hydroxyapatite single crystal architecture for enhanced osteoblast adhesion

Abstract

Hydroxyapatite (HAp) single crystals with hexagonal rod-like shapes have attracted much attention in orthopaedic and tissue engineering fields, as they have a similar shape to HAp mineral components in human natural bone. The significance of HAp crystals lies in the high surface reactivity of their exposed facets with water and some biological molecules. However, few studies have been reported on the fabrication of an integrated architecture with these single crystals, with an attempt to utilise the benefits of the reactive facets to improve the functionality of the biointerface. In this study, an integrated three dimensional (3D) architecture is formed by nano/submicron HAp single crystals (with an elongated hexagonal bipyramid shape) on HAp-tricalcium phosphate (TCP) biphasic ceramics using a simple one-step method. The described method, based on a crystallographic controlled dissolutionrecrystallization mechanism, allows HAp single crystals to coalesce, forming an interconnected structure. The single crystal structure can be varied by adjusting the proportion of HAp (mother phase) and aor b-TCP (nutrient phase). The resultant architectures are proven to significantly enhance hydrophilicity and promote primary human osteoblast (HOB) adhesion.

On-Demand Guided Bone Regeneration with Microbial Protection of Ornamented SPU Scaffold with Bismuth-Doped Single Crystalline Hydroxyapatite: Augmentation and Cartilage Formation

“…Furthermore, this SAED pattern supported the formation of the hexagonal structure of HA with well-defined hexagonal facets, and the strong single crystal is in good agreement with the WXRD results. Besides, it realized that the crystal growth of the hexagonal HA crystal was parallel to the long axis (preferentially c -axis) of the hexagonal rod with the [001] crystallographic direction . The interplanar spacing distance (lattice fringes) measured from the HRTEM photomicrograph (Figure c) of the single nanorod at 5 nm scale is ≈0.07 nm, corresponding to the interplanar spacing of the (001) of the hexagonal single crystalline Bi-nHA crystals.…”

“…Figure 2b reflects the prominent spots from the SAED, with the clear diffraction patterns confirming the formation of strong single crystalline Bi-nHA, which is in agreement with the earlier reports. 41,42 For the undoped nHA nanorods, it demonstrates very clear ring patterns, highlighting the random orientation (polycrystalline) of the crystalline phase of nHA rods (Figure 2e). Furthermore, this SAED pattern supported the formation of the hexagonal structure of HA with well-defined hexagonal facets, and the strong single crystal is in good agreement with the WXRD results.…”

Refining nanotopographical features on bone implant surfaces by altering surface chemical compositions

“…Cell culture and cell seeding on the TiO 2 , 10%Nb 2 O 5 /TiO 2 , 30% Nb 2 O 5 /TiO 2 , 50%Nb 2 O 5 /TiO 2 and Nb 2 O 5 coatings were performed as previously described. [15][16][17][18] Briey, primary human osteoblasts (HOBs) were rst isolated from normal human trabecular bone, with a permission to use discarded human tissue granted by the Human Ethics Committee of the University of Sydney and informed consent was obtained. HOBs were cultured at 37 C in an atmosphere of 5% CO 2 .…”

Electrospun Poly(butylene-adipate-co-terephthalate)/Nano-hyDroxyapatite/Graphene Nanoribbon Scaffolds Improved the In Vivo Osteogenesis of the Neoformed Bone

“…The TEM image of PBAT with nHAp ( Figure 1 D) and nHAp/GNR ( Figure 1 E) depicts lattice fringes and a well-defined and crystalline structure for both included nanoparticles. A d-spacings of 0.28, 0.34, and 0.69 nm can be assigned to the (211), (002), and (001) lattice planes of HAp (JCPDS # 86–1203), respectively [ 36 , 37 ]. Figure 1 C1 charts an increase in the average diameter of the fibers, which can be attributed to the decrease in used solvent system (dielectric constant), electrical conductivity and the consequent decrease in the density of pure charge in the jet due to the presence of GNR.…”