Authors: Ricardo M.P. da Silva, P.B. Malafaya, João F. Mano, Rui L. Reis
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Authors: Bao Hui Su, Jun Guo Ran, Li Gou, Fang Hu Wang, Hai Su Guo
Abstract: BGC, HA, β-TCP and biphase calcium phosphate (β-TCP/HA) were modified by using the cold plasma technique in the present study. The study results came from the formation of bone-like apatite in SBF and results of osteoblast culture in vitro, SEM, XPS, and XRD. The results showed that the formation of bone-like apatite on bioceramics modified by cold plasma was easier than that of no modification and the growth of osteoblast could be promoted. The active mechanism was that impact
on bioceramics by means of the particles with high energy and high activity led to rough and etched surface of bioceramics, as well as the distortion of bioceramics crystal, which increased solubility of materials and local concentration of Ca and P ion. It was helpful for the formation of bone-like apatite. It was showed that the modification using cold plasma technique could increase the activity of
bioceramics.
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Authors: Min Chul Kim, Kyoung Nam Kim, Kwang Mahn Kim, Seong Ho Choi, Chong Kwan Kim, Racquel Z. LeGeros, Yong Keun Lee
Abstract: The development of phosphate glasses for use in orthopaedic implants has attracted much interest because their chemical and physical properties make them suitable for use as bone-bonding materials. We prepared various compositions of CaO-P2O5-MO or CaO-P2O5-M2O (M: K, Li, Na, Mg, Zn) glasses to measure ion release, solubility and bioactivity. The compositions with (Ca,M)/P molar
ratio 0.6 were fixed P2O5 mol% content at 45.45 mol%, and varying MO or M2O mol% at 10, 20 and 30 mol%. Ca2+ ion release properties were investigated in 0.1M potassium acetate with pH 6 at 37oC by immersing 50 mg of powder into 100 ml of acidic buffer solution. The highest and lowest extent of released Ca2+ ion was observed for composition with 10 mol% of K2O and 30 mol% of MgO, respectively. The weight loss in distilled water at 37oC was measured. Solubility increased with
decreasing CaO content, but decreased with increasing MgO content. Bioactivity in the simulated body fluid at 37oC was measured.
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Authors: Bin Xiao, Wei Zhong Yang, Da Li Zhou, Guang Fu Yin, Huai Qing Chen
Abstract: Bioactive composite of apatite-wollastonite(AW)/β-tricalcium phosphate (β-TCP) was
prepared. The nucleation and growth of bio-apatite on the surface of AW/β-TCP ceramic in simulated
body fluid (SBF) were investigated. The surface morphological structure, phase compositions and
microstructure of the materials were characterized by scan electron microscopy (SEM), X-ray diffraction
(XRD) and infrared spectroscopy (IR); Results show that the surfaces of the AW/β-TCP composite
ceramic are covered with a layer of carbonate hydroxyapatite (HCA) when soaked in SBF, which
indicates their bioactivity; Such HCA layer is composed of fine ball-like HA granules. With excellent
bioactivity and bio-absorption, AW/β-TCP bioactive composite ceramic is expected to be a good
candidate for bone substitutes and bone tissue engineering scaffolds.
1692
Authors: Marziyeh Abbasi-Shahni, Saeed Hesaraki, Ali Asghar Behnam-Ghader, Masoud Hafezi-Ardakani
Abstract: In this study, nanocomposites based on of β-tri calcium phosphate (β-TCP) and 2.5-10 wt% merwinite nanoparticles were prepared and sintered at 1100-1300°c. The mechanical properties were investigated by measuring compressive strength and fracture toughness. Structural properties were evaluated by XRD, TEM and SEM analysis, and the in vitro bioactivity was studied by soaking the samples in simulated body fluid (SBF). The mechanical strength of the sintered samples were increased, by increasing the amount of merwinite phase up to 5 wt%, whereas it decreased when the samples were sintered at 1100 and 1200°c. Nanostructured calcium phosphate layer was formed on the surfaces of the nanocomposites within 1 day immersion in simulated body fluid. Because of appropriate mechanical properties the composite is suggested to be used as substitute for hard tissue.
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