Preparation, solubility, and cytocompatibility of zinc-releasing calcium phosphate ceramics

Abstract

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 %.

Cytocompatibility evaluation of hydroxyapatite/collagen composites doped with Zn+2

“…Zinc is an essential trace element with stimulatory effects on osteoblastic cell proliferation and bone formation in vitro and in vivo. It hold an inhibitory effect on osteoclastic bone resorption [6,7]. Several researchers have attempted to doper materials with Zn +2 at low concentrations increasing the bioactivity of bone cells [4,[6][7][8] and decreasing and regulating the inflammatory reaction [9].…”

“…The literature studies related that zinc released from the ZnCaP stimulates osteoblastic activities [6,7,9]. Nevertheless, zinc is known as a potent inhibitor of the crystal growth of apatite, which is a controversial issue.…”

Preparation and characterization of fluorinated porcine hydroxyapatite

“…However, among the frequently used animal bones, porcine bone bears the closest resemblance to human bone in terms of bone macrostructure and microstructure, bone composition, and bone remodeling rate 5) . Numerous studies were carried out on ion incorporation (e.g., F − , Mg 2+ , Sr 2+ , CO3 2− ) into synthetic apatite [6][7][8][9][10][11][12] and biological apatite (such as bovine bone, natural coral, or cuttlefish bone) 3,[13][14][15][16] . In general, these studies showed that ion-incorporated hydroxyapatite composites were promising candidates for biomedical applications.…”

Preparation and Characterization of Zinc-substituted Bioactive Glasses with Sol–gel Method

“…The use of synthetic bone substitutes for delivery of zinc ions has recently gained attention in research communities. There are numerous studies regarding the development and evaluation of zinc-containing calcium phosphate ceramics both in vitro and in vivo (9)(10)(11)(12)(13) . There are also reports concerning the use of different bioactive glass compositions as short-or longterm zinc delivery vehicles (14)(15)(16)(17) .…”