PRECIPITATION OF HYBRID HYDROXYAPATITE / AUTOFIBRIN NANOCOMPOSITES

Abstract

Hybrid composites based on hydroxyapatite and autofibrin were synthesized by precipitation in a medium with pH=9. Soft precipitation conditions and rapid isolation of the composite precipitates favored preservation of a biopolymer matrix of autofibrin. An effect of fibrin macromolecules contributed to destabilization of the amorphous calcium phosphate phase and formation of stoichiometric hydroxyapatite. The medium of the citrated plasma stimulated precipitation of calcium-deficient hydroxyapatite with x≈0,1 and the Ca/P ration of 1,65 which transformed into the mixture of hydroxyapatite / β-tricalcium phosphate at 800°С. Biomimetic apatite composites were synthesized with an addition of 30 vol. % of a Simulated Body Fluid (SBF) model solution. The effect of Mg^2+, CO3^2- ions of SBF promoted the stabilization of amorphous calcium phosphate and formation of carbonated hydroxyapatite that exhibited thermal stability up to 800°С. The cummulative effect of autofibrin and ions of induced SBF provided controlling composition of the mineral part of hybrid nanocomposites without disruption of an autofibrin matrix.

Keywords

• hybrid nanocomposite
• hydroxyapatite
• fibrin
• citrated plasma
• amorphous calcium phosphate
• calcium-deficient hydroxyapatite
• carbonated hydroxyapatite