A microstructural study of the degradation and calcium release from hydroxyapatite-calcium oxide ceramics made by infiltration.
Hydroxyapatite pellets, partially densified in a low-temperature heat treatment, were infiltrated with calcium nitrate solution followed by in-situ precipitation of Ca(OH)2and CaCO3. The infiltrated bodies were then densified to high relative density and the calcium carbonate transformed to calcium oxide during sintering and resulted in biphasic hydroxyapatite-CaO ceramics. This work investigated the influence of the infiltration on surface morphology, weight change, and microstructural-level degradation caused by exposure to saline at pH=7.4 and a temperature of 20°C. The CaO rendered the materials more susceptible to degradation, and released calcium into the saline faster than single phase, calcium deficient hydroxyapatite (HA) that were used as a control. In consequence, these ceramics could be used to release calcium into the culture microenvironments of bone tissue or bone marrow cells next to a scaffold surface.
Department of Mechanical Engineering and Materials Science, University of Pittsburgh, 3700 O'hara Street, Pittsburgh, PA 15261, USA. Electronic address: qiz43@pitt.edu.
Qinghao
Q
Zhang
Department of Surgery, McGowan Institute for Regenerative Medicine, University of Pittsburgh, 3025 East Carson Street, Pittsburgh, PA 15203, USA.
Eva
E
Schmelzer
Department of Surgery, McGowan Institute for Regenerative Medicine, University of Pittsburgh, 3025 East Carson Street, Pittsburgh, PA 15203, USA; Department of Bioengineering, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, 3700 O'hara Street, Pittsburgh, PA 15261, USA.
Jörg C
JC
Gerlach
Department of Mechanical Engineering and Materials Science, University of Pittsburgh, 3700 O'hara Street, Pittsburgh, PA 15261, USA.
Ian
I
Nettleship
D002118:Calcium / Q000737:chemistry*; D017610:Calcium Compounds / Q000737:chemistry*; D002516:Ceramics / Q000737:chemistry*; D017886:Durapatite / Q000737:chemistry*; D008422:Materials Testing / Q000379:methods*; D008853:Microscopy; D010087:Oxides / Q000737:chemistry*; D012995:Solubility; D012996:Solutions; D013499:Surface Properties; D013997:Time Factors; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction
D017610:Calcium Compounds; D010087:Oxides; D012996:Solutions; D014867:Water; D017886:Durapatite; C016538:lime; D002118:Calcium
Bioceramics; Degradation; Hydroxyapatite; Infiltration