title: Fabrication of low temperature macroporous hydroxyapatite scaffolds by foaming and hydrolysis of an alpha-TCP paste.
abstract: The development of the new technologies of bone tissue engineering requires the production of bioresorbable macroporous scaffolds. Calcium phosphate cements are good candidate materials for the development of these scaffolds, as an alternative to the traditional porous sintered ceramics. In this work a novel two-step method, based in the foaming of an alpha-tricalcium phosphate (alpha-TCP) cement paste and its subsequent hydrolysis to a calcium deficient hydroxyapatite (CDHA) is presented. The foaming agent was a hydrogen peroxide (H2O2) solution, which decomposes in water and oxygen gas. CDHA foams, which combined an interconnected macroporosity with a high microporosity were obtained. The apatitic phase obtained by the hydrolysis reaction was more similar to the biologic one, in terms of chemical composition, crystallinity and specific surface than the hydroxyapatites obtained by sintering. The percentage of porosity in the foams reached a 66%. It was shown that it was possible to control the porosity, and pore size and shape by different processing parameters such as the liquid-to-powder ratio, the concentration of the H2O2 solution and the particle size of the powder.
authors.affiliation: Biomaterials Division, Department of Materials Science and Metallurgy, Biomedical Engineering Research Centre, Technical University of Catalonia (UPC), Av. Diagonal 647, E08028 Barcelona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Almirall
authors.forename: G
authors.initials: G
authors.lastname: Larrecq
authors.forename: J A
authors.initials: JA
authors.lastname: Delgado
authors.forename: S
authors.initials: S
authors.lastname: Martínez
authors.forename: J A
authors.initials: JA
authors.lastname: Planell
authors.forename: M P
authors.initials: MP
authors.lastname: Ginebra
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D001843:Bone Cements / Q000737:chemistry*; D018786:Bone Substitutes / Q000737:chemistry*; D002130:Calcium Phosphates / Q000737:chemistry*; D019245:Compressive Strength; D017886:Durapatite / Q000737:chemistry*; D005740:Gases / Q000737:chemistry; D006868:Hydrolysis; D008420:Manufactured Materials / Q000032:analysis; D008422:Materials Testing; D009824:Ointments; D010316:Particle Size; D044367:Phase Transition; D016062:Porosity; D011208:Powders; D013499:Surface Properties; D013718:Tensile Strength; D023822:Tissue Engineering
chemical_list: D001672:Biocompatible Materials; D001843:Bone Cements; D018786:Bone Substitutes; D002130:Calcium Phosphates; D005740:Gases; D009824:Ointments; D011208:Powders; C485828:alpha-tricalcium phosphate; D017886:Durapatite