Preparation, solubility, and cytocompatibility of zinc-releasing calcium phosphate ceramics.
Zinc is an essential trace element with stimulatory effects on bone formation. Therefore, zinc was doped into beta-tricalcium phosphate to develop zinc-releasing biomaterials to promote bone formation. The zinc-doped beta-tricalcium phosphate, beta-tricalcium phosphate, and hydroxyapatite powders were mixed at a (Ca+Zn)/P molar ratio of 1.60, followed by sintering into a dense body at 1100 degrees C for 1 h. The sintered body was a composite ceramic consisting of zinc-doped beta-tricalcium phosphate and hydroxyapatite phases. The composite ceramic contained zinc oxide when the zinc content was higher than 1.20 wt %. The composite ceramic released zinc under pseudophysiological conditions. However, the release of calcium and phosphate decreased with an increase in zinc content in a range higher than 0.12 wt % owing to a decrease in solubility of the zinc-doped beta-tricalcium phosphate phase. Proliferation of osteoblastic MC3T3-E1 cells was significantly increased on the composite ceramic with a zinc content from 0.6 to 1.20 wt %, compared with those without zinc. When the zinc content was higher than 1.20 wt %, release of zinc from the zinc oxide caused cytotoxicity. Therefore, the zinc content of the composite ceramic must be <1.20 wt %.
Ito
A
A
National Institute for Advanced Interdisciplinary Research, MEL, MITI, 1-1-4 Higashi, Tsukuba-shi, Ibaraki 305-8562, Japan.
Ojima
K
K
Naito
H
H
Ichinose
N
N
Tateishi
T
T
D000818:Animals; D001672:Biocompatible Materials; D016723:Bone Remodeling; D018786:Bone Substitutes; D002130:Calcium Phosphates; D002460:Cell Line; D002516:Ceramics; D010006:Osteoblasts / Q000166:cytology / Q000502:physiology; D015032:Zinc
D001672:Biocompatible Materials; D018786:Bone Substitutes; D002130:Calcium Phosphates; D015032:Zinc