Gradient Rare-Earths Bioceramic Composite Coating Fabricated by Wide-Band Laser Cladding and its Bioactivity

2009 ◽  
Vol 610-613 ◽  
pp. 1224-1226 ◽  
Author(s):  
Qi Bin Liu ◽  
Ling Wu ◽  
Bang Cheng Yang

A gradient bioceramic composite coating was prepared by wide-band laser cladding technique on TC4 alloy surface. The influence of rare earths oxide CeO2 on microstructure of bioceramic coating was studied. The experimental results indicated that CeO2 plays an important role in inducing HA + β-TCP formation. There is almost no HA+β-TCP in bioceramic coating without CeO2. When CeO2 content is higher than 0.2 wt.%, the amount of HA+β-TCP catalyzed by CeO2 gradually increases. The amount of HA+β-TCP becomes largest when CeO2 content is up to 0.4wt%. However, when CeO2 content ranges from 0.6 wt.% to 0.8 wt.%, the amount of synthesizing HA+β-TCP conversely goes down. Through cell culture experiment in vitro, the effect of bioceramic coating with different CeO2 contents on the expression of characteristic protein is investigated. The results show that the largest amount of expression of hydroxyproline(Hyp) at 2d and alkaline phosphatase(ALP) at 6d on coating is complied with 0.4wt.% CeO2, The result indicates that bioactivity of bioceramic coating is dependent on the amount of HA + β-TCP catalyzed by different CeO2 contents.

2013 ◽  
Vol 668 ◽  
pp. 91-95
Author(s):  
Qi Bin Liu ◽  
Bang Cheng Yang

To improve the quality of bioceramic gradient coatings, wide band laser cladding technique was adopted to produce a kind of gradient composite bioceramic coating, which combines the good biocompatibility of HA and β-TCP with good toughness and strength of TC4 alloy. The rare earths oxide La2O3 was added to improve the properties of the bioceramic coating. The results indicate that when the adding of La2O3 is 0.6wt%, the ceramics coating is of the largest amount of HA and β-TCP catalyzed, and the number of cells proliferated and the ALP secreted on coatings is the biggest, which indicates that the biocompatibility and bioactivity of gradient bioceramic coating is the best. The biocompatibility and bioactivity are closely related to the amount of HA and β-TCP catalyzed by La2O3.


2007 ◽  
Vol 34 (S 2) ◽  
Author(s):  
C Funke ◽  
J Hübener ◽  
H Wolburg ◽  
T Schmidt ◽  
H Toresson ◽  
...  

Applied laser ◽  
2012 ◽  
Vol 32 (5) ◽  
pp. 384-389
Author(s):  
李明 Li Ming ◽  
汪震 Wang Zhen
Keyword(s):  

2005 ◽  
Vol 288-289 ◽  
pp. 351-354 ◽  
Author(s):  
Qi Bin Liu ◽  
Long Jiang Zou ◽  
Min Zheng ◽  
Chuang Dong

In the present paper, bioceramic coating with gradient compositional design was prepared on surface of Ti alloy by using wide-band laser cladding. Effect of rare earth Y2O3 content on gradient bioceramic composite coating was studied. The experimental results indicated that adding rare earth can refine grain. Different contents of rare earth affect formation of HA andβ-TCP in bioceramic coating. With increase of rare earth content, HA andβ-TCP were synthesized. When content of rare earth ranged from 0.4% to 0.6%, the active extent of rare earth in synthesizing HA andβ-TCP got best, which indicated that “monosodium glutamate” effect of rare earth played a dominant role. However, when rare earth content was up to 0.8%, the active extent of rare earth in synthesizing HA and β-TCP conversely went down, which demonstrated that rare earth gradually lost its catalysis in manufacturing HA andβ-TCP.


2013 ◽  
Vol 295-298 ◽  
pp. 78-81
Author(s):  
Hua Liu ◽  
Hua Guang Li ◽  
Su Liu

AIM: To investigate the mechanism of hyaluronic acid on rabbit chondrocyte apoptosis in vitro induced by NO. METHODS: We cultured rabbit chondrocytes as normal group and added SNP after cultured 24 h as model group. Treated group was added HA. We used cell culture experiment. We tested the activity of mitochondria though MTT. The flow cytometry detected mitochondrial membrane potential, the percentage of apoptosis and intracellular free calcium concentration.RESULTS: HA could elevate the active of chondrocyte mitochondria and MMP; it could decrease the rate of chondrocyte apoptosis and intracellular free calcium concentration.CONCLUSION: HA can inhibit the lowering of the MMP in chondrocyte, which has a stable role on MMP and inhibit apoptosis occurred. This effect may be related to inhibiting of intracellular calcium overload chondrocytes.


2007 ◽  
Vol 342-343 ◽  
pp. 685-688 ◽  
Author(s):  
Qi Bin Liu ◽  
Wen Fei Li ◽  
Bang Cheng Yang

In this study, microstructure and biocompatibility of gradient bioceramic composite coating fabricated by Wide-Band Laser Cladding is investigated. The experimental results indicate that the coating consists of an alloyed transition layer and the bioceramic coating. The bioceramic coating is mainly comprised of HA, CaTiO3, CaO, α-TCP, β-TCP and TiO. The coral-shaped structure and short-rod piled structure existing on the surface of coating. After the implantation of the bioceramic coatings into dogs’ femur for 6, 12, and 24 weeks, hypersusceptibility, rejection and pathological changes are not found. No fiber cyst, necrosis of bone tissue and chronic inflammation obviously appear through slice observation of hard tissues. The bioceramic coating with different ratios of Ca : P have different abilities to induce osteogenesis. At Ca: P=1.4 and 0.6wt.% Y2O3 (No.3 sample), the bioceramic coating is of best bioactivity and biocompatibility.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Moon-Jeong Choi ◽  
R. Pierson ◽  
Yongmin Chang ◽  
Haiquing Guo ◽  
Inn-Kyu Kang

Arg-Gly-Asp-Ser (RGDS), a typical membrane-permeable carrier peptide, was conjugated with mercaptoisobutyric acid-immobilized CdTe quantum dot (CTNPs) to enhance the intracellular uptake of quantum dots. Mean size of mercaptoisobutyric acid-immobilized quantum dots (37 nm) as determined by dynamic light scattering was increased up to 54 nm after RGDS immobilization. It was found, fromin vitrocell culture experiment, that fibroblast (NIH 3T3) cells were well proliferated in the presence of RGDS-conjugated quantum dots (RCTNPs), and the intracellular uptake of CTNPs and RCTNPs was studied by means of ICP and fluorescence microscopy. As a result, the RCTNPs specifically bound to the membrane of NIH 3T3 cells and almost saturated after 6 hours incubation. The amount of RCTNPs uptaken by the cells was higher than that of CTNPs, demonstrating the enhancing effect of RGDS peptide conjugation on the intracellular uptake of quantum dots (QDs).


2007 ◽  
Vol 330-332 ◽  
pp. 569-572 ◽  
Author(s):  
Sen Yang ◽  
Hau Chung Man

To accelerate the bone growth around a metallic implant and to achieve the mechanical characteristics needed for biomedical applications, a HA/Ti composite coating was produced on NiTi alloy substrate by laser cladding. The chemical compositions, microstructures and surface morphology of the cladded layer were analyzed using energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and X-ray diffractometry (XRD). The experimental results showed that an excellent metallurgical bonding between the coating and the substrate was obtained. Owing to decomposition of HA under irradiation of high power laser, the microstructures in bioceramics coating were mainly composed of CaO, CaTiO3, Ti4P3, and HA phases. In vitro experimental result showed that HA/Ti composite coating made the bioactivity of NiTi alloy improve remarkably, which would promote the bone growth and could restrain Ni ion releasing from NiTi alloy.


Applied laser ◽  
2013 ◽  
Vol 33 (6) ◽  
pp. 628-632
Author(s):  
李宾 Li Bin ◽  
田兴强 Tian Xingqiang ◽  
汪震 Wang Zhen

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