Morphological variation of hydroxyapatite grown in aqueous solution based on simulated body fluid

Abstract

We successfully controlled the morphology of hydroxyapatite (HAp) grown in a solution system based on simulated body fluid (SBF). Nanometric low-dimensional forms, such as sheets and needles elongated in the c axis, were produced with phosphate-surplus (or calcium-deficient) HAp in the solution at human body temperature. The nanoneedles were obtained on the seed crystals under gentle growth conditions at pH 6.5; the nanosheets were grown through coalescence of tiny grains or needles at a relatively high growth rate above pH 7.0. On the other hand, micrometric bulky hexagonal shapes and faceted plates of semi-stoichiometric HAp were grown under hydrothermal conditions at pH 7.0 and 7.4, respectively. The variation of the morphology is discussed on the basis of the change of the growth mode of HAp crystals depending on the supersaturated conditions.

Incorporation of Fucoidan in β-Tricalcium phosphate-Chitosan scaffold prompts the differentiation of human bone marrow stromal cells into osteogenic lineage

“…The bone bonding ability and osteointegration ( in vivo bioactivity) of a scaffold are occasionally predicted by its capability to form an apatite layer on its surface in vitro upon immersion in SBF (except in special cases, where the scaffold can be integrated within the host bone tissue without detection of a visible apatite layer on their surface) 18 19 . Interestingly, the overall findings of the present study conform, both quantitatively (Ca/P ratio) and qualitatively (morphology), to those reported previously with regard to apatite formation after the initial stages of immersion in SBF 20 21 . The calcium-deficient ACP is known as octacalcium phosphate (OCP), a precursor of hydroxy apatite HA, which later crystallizes into bone-like apatite upon equilibrium 22 23 .…”

About the Genetic Mechanisms of Apatites: A Survey on the Methodological Approaches

“…A more precise problem [47] stands in line with this way of thinking: "Focusing on nano-HAp morphology, needlelike [48][49][50][51] and platelike [52][53][54] nano-particles can be prepared, while in bone tissue only the second type seems to be present [55][56][57]. For both morphologies the prevailing surface terminations are of the {010} type, which in the case of needlelike nano-HAp are the lateral facets of the hexagonal nano-particles elongated along the crystallographic c-axis, while, for the platelike nano-particles they are the basal facets of nano-particles preferentially grown along both the c-and a-(or b-) axis [53,54,58] breaking the crystal symmetry through a mechanism still matter of investigation [52,58].…”

An effective route to the synthesis of carbonated apatite crystals with controllable morphologies and their growth mechanism

“…The nanosheet HAp crystal was observed by Kobayashi et al in a supersaturated solution system based on SBF. 39 Lin, et al used urea as the homogeneous precipitation reagent and obtained a product with a nanosheet morphology. 40 In the presence of HMT, the formation of the nanosheet HAp nanocrystallites facilitated aggregation parallel to the c axis.…”