Factors affecting the structure and properties of an injectable self-setting calcium phosphate foam.
One of the main challenges in the investigation on calcium phosphate cements (CPC) lies in the introduction of macroporosity, without loosing the self-setting ability and injectability, characteristic of the cement-type materials. The benefits of macroporosity are related to the enhancement of bone regeneration mechanisms, such as angiogenesis and tissue ingrowth. In this work, the feasibility to obtain self-setting injectable macroporous hydroxyapatite foams by the incorporation of a protein-based foaming agent to a CPC is demonstrated. Albumen is combined with an alpha-tricalcium phosphate [Ca3(PO4)2, alpha-TCP] paste, which hydrolyzes to a calcium deficient hydroxyapatite during the setting reaction. A systematic study is presented, where the effect of different processing parameters is analyzed in terms of porosity, setting properties, injectability, and compressive strength. Self-setting foams with porosities up to 70%, which maintain their porous structure after injection, are obtained. These injectable foams can be used both for direct in vivo applications and for the fabrication of low temperature tissue engineering scaffolds.
Ginebra
Maria-Pau
MP
Biomaterials Division, Department of Materials Science and Metallurgy, Biomedical Engineering Research Centre, Technical University of Catalonia (UPC), Av. Diagonal 647, E08028 Barcelona, Spain. maria.pau.ginebra@upc.edu
Delgado
José-Angel
JA
Harr
Ingela
I
Almirall
Amisel
A
Del Valle
Sergio
S
Planell
Josep A
JA
D000418:Albumins; D001843:Bone Cements / Q000138:chemical synthesis* / Q000737:chemistry; D002130:Calcium Phosphates / Q000737:chemistry*; D017886:Durapatite; D007267:Injections; D010012:Osteogenesis; D016062:Porosity; D023822:Tissue Engineering / Q000379:methods
D000418:Albumins; D001843:Bone Cements; D002130:Calcium Phosphates; D017886:Durapatite; C020243:calcium phosphate