Stimulatory effect of zinc-releasing calcium phosphate implant on bone formation in rabbit femora

Abstract

Although hydroxyapatite (HAP) and tricalcium phosphate (TCP) are currently used as bone graft substitutes or coatings on metallic prostheses because of their excellent biocompatibility and osteoconductivity, they do not stimulate bone formation or inhibit bone resorption. Zinc, an essential trace element in many animals, has a direct specific proliferative effect on osteoblastic cells and has a potent and selective inhibitory effect on osteoclastic bone resorption in vitro. Therefore, zinc-containing beta-tricalcium phosphate (ZnTCP) ceramics and composite ceramics of ZnTCP and HAP (ZnTCP/HAP) were implanted in the femora of New Zealand White rabbits for 4 weeks to promote bone formation. The implants were sintered ceramics with zinc contents of 0 (control), 0.063, 0.316 and 0.633 wt %. Histological and histomorphometrical investigation of the undecalcified sections revealed an increase by 51% (p =.0509) in the area of newly formed bone around the ZnTCP/HAP implants of 0. 316 Zn wt % compared with the control. Plasma zinc concentration was unchanged. An increased bone resorption on the endosteal surface was observed when ZnTCP and ZnTCP/HAP of 0.633 Zn wt % were implanted. To promote bone formation, the optimum zinc content of the calcium phosphate ceramics was therefore 0.316 wt %.

Coral Exoskeletons as a Precursor Material for the Development of a Calcium Phosphate Drug Delivery System for Bone Tissue Engineering

“…11) This has motivated the syntheses of zinc-tricalcium phosphates (Zn-TCP), which in appropriate concentration and dosage, have been shown to have a stimulatory effect in the treatment of osteoporosis. [12][13][14] Traditionally, the synthesis of Zn-TCP requires high temperature sintering at around 800°C. By employing an additional hydrothermal treatment after the conversion of the β-TCP, Zn-TCP can be synthesized at relatively lower temperature (220°C).…”

Dissolution mechanisms of .BETA.-tricalcium phosphate doped with monovalent metal ions

“…28)34) In fact, Zn-TCP has been shown to enhance bone growth via increased cell growth and viability. 35) Conversely, the presence of toxic metal ions such as Cd, Cr, and Ni inhibits bone growth. 36),37) Consequently, it is also important for biomedical applications to clarify the dissolution mechanism, particularly the elution behavior of metal ions from biomaterials.…”

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) .…”