The biodegradation mechanism of calcium phosphate biomaterials in bone.
This study was undertaken to understand the biodegradation mechanisms of calcium phosphate (Ca-P) biomaterials with different crystallization. Two types of sintered Ca-P porous ceramic (HA and beta-TCP) and a Ca-P bone cement (CPC) were implanted into cavities drilled in rabbit femoral and tibiae condyles. The results have shown that a material biodegradation was rapid in the beta-TCP and the CPC, but very weak in the HA. This biodegradation presented a decrease of material volume from the periphery to the center as well as a particle formation causing phagocytosis by numerous macrophages and multinucleated giant cells in the CPC. In the beta-TCP, there was a peripheral and central decrease of material volume as well as an absence of particle formation or visible phagocytosis. The process of biodegradation is considered to be directly influenced by the type of material crystallization. The sintered bioceramics processed at a high temperature exhibit good crystallization and are primarily degraded by a process dependent on interstitial liquids. However, the bone cement is formed by physicochemical crystallization and is degraded through a dissolution process associated with a cellular process.
Laboratoire Interface Matrice Extracellulaire Biomatériaux, Faculté d'Odontologie de Marseille, France. ir2bberck@hopale.com
Jianxi
J
Lu
Michel
M
Descamps
Jacques
J
Dejou
Gilles
G
Koubi
Pierre
P
Hardouin
Jacques
J
Lemaitre
Jean-Pierre
JP
Proust
D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000378:metabolism*; D001673:Biodegradation, Environmental; D001843:Bone Cements / Q000737:chemistry / Q000378:metabolism; D018786:Bone Substitutes / Q000737:chemistry / Q000378:metabolism; D002130:Calcium Phosphates / Q000378:metabolism* / Q000627:therapeutic use; D005269:Femur / Q000166:cytology / Q000601:surgery; D008264:Macrophages; D008422:Materials Testing; D010006:Osteoblasts; D010587:Phagocytosis; D011817:Rabbits; D013977:Tibia / Q000166:cytology / Q000601:surgery
D001672:Biocompatible Materials; D001843:Bone Cements; D018786:Bone Substitutes; D002130:Calcium Phosphates; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; C485838:calcium phosphate, monobasic, anhydrous; C020243:calcium phosphate; C485829:calcium phosphate, dibasic, anhydrous