Biomorphous porous hydroxyapatite-ceramics from rattan (Calamus Rotang)

Abstract

The three-dimensional, highly oriented pore channel anatomy of native rattan (Calamus rotang) was used as a template to fabricate biomorphous hydroxyapatite (Ca(5)(PO(4))(3)OH) ceramics designed for bone regeneration scaffolds. A low viscous hydroxyapatite-sol was prepared from triethyl phosphite and calcium nitrate tetrahydrate and repeatedly vacuum infiltrated into the native template. The template was subsequently pyrolysed at 800 degrees C to form a biocarbon replica of the native tissue. Heat treatment at 1,300 degrees C in air atmosphere caused oxidation of the carbon skeleton and sintering of the hydroxyapatite. SEM analysis confirmed detailed replication of rattan anatomy. Porosity of the samples measured by mercury porosimetry showed a multimodal pore size distribution in the range of 300 nm to 300 microm. Phase composition was determined by XRD and FT-IR revealing hydroxyapatite as the dominant phase with minimum fractions of CaO and Ca(3)(PO(4))(2). The biomorphous scaffolds with a total porosity of 70-80% obtained a compressive strength of 3-5 MPa in axial direction and 1-2 MPa in radial direction of the pore channel orientation. Bending strength was determined in a coaxial double ring test resulting in a maximum bending strength of approximately 2 MPa.

Medical Application of Calcium Orthophosphate Bioceramics

“…Besides, an HA suspension can be cast into a porous CaCO 3 skeleton, which is then dissolved, leaving a porous network [410]. 3D periodic macroporous frame of HA has been fabricated via a template-assisted colloidal processing technique [420,421]. A superporous (~ 85% porosity) HA ceramics was developed as well [450,451].…”

Weaving Enclosure. Material computation and novel forms of crafting

“…These anatomical features and the constant sectional composition and diameter allow for a computational prediction of its behavior. Moreover, its mechanical properties have proved to be relevant for concrete reinforcements (Obilade et al 2014) as well as for bone replacement, due to its porous structure permitting blood vessels and other accessory tissues to penetrate it, allowing seamless integration into the host bone (Eichenseer et al 2009). Rattan's considerable length (up to 100 meters) and vascular morphology contribute to define a lightweight material with high tensile properties and elastic bending capabilities.…”

Calcium orthophosphate bioceramics

“…More to the point, a HA suspension can be cast into a porous CaCO 3 skeleton, which is then dissolved, leaving a porous network [521]. 3D periodic macroporous frame of HA has been fabricated via a template-assisted colloidal processing technique [526,527]. In addition, porous HA bioceramics might be prepared by using different starting HA powders and sintering at various temperatures by a pressureless sintering [523].…”