bluuebunny/crossref_metadata_2025 huggingface dataset:
Cell Repopulation in Calcium Phosphate Hybridized Tendon Graft
Authors: Mutsuzaki Hirotaka , Sakane Masataka , Katayoshi Yumi , Hattori Sinya , Nakajima Hiromi , Tanaka M. , Ochiai Naoyuki
Published: March 2009

Calcium phosphate (CaP) hybridized to a whole tendon graft delayed cell
repopulation in anterior cruciate ligament (ACL) reconstruction in rabbits. However, a tendon
graft masked with an adhesive tape at the intra-articular (IA) portion to prevent CaP
hybridization did not delay cell repopulation. Synovial tissues can adhere to the tendon graft and
can invade the tendon graft masked at the IA portion. The masking induced an effect similar to
that of the unhybridized tendon graft. The CaP hybridized tendon grafts masked at the IA portion
showed cell repopulation 2 weeks earlier than the unmasked CaP hybridized tendon grafts.
Reconstructing Box-Like Bone Defect of Mandible with In Vivo Tissue Engineering Bone
Authors: Yao Jin Feng , Zhang Y.Z. , Bao C.Y. , Sun L.Y. , Hao X.M. , Fan Hong Song , Zhang Xing Dong
Published: March 2009

The purpose of this study was to explore the feasibility of repairing massive bone defect with in vivo tissue engineering(TE) bone, and to provide experimental evidence for the application of in vivo TE bone into clinic in the future. Six calcium phosphate ceramics (Ca-P ceramics) columns were prepared, and then immersed in dynamic revised simulated body fluid (RSBF). 72 hours later, the bone-like apatite was formed on the surface and pore walls of ceramics. Three dogs were used in this study. Two ceramic columns were implanted bilaterally in the femoral muscles of each dog to construct living bone graft of in vivo TE bone. 6 weeks after implantation, they were transplanted to the box-like bone defects sites created in bilateral mandible of the same animals. The dogs were sacrificed at 8, 12 week after operation respectively. Samples were harvested for gross observation, X-ray examination, tetracycline fluorescence labeling, SPECT and histological observation. These results demonstrated that as a living bone graft, in vivo TE bone participated in the bone metabolism of host, and integrated with the host bone. It is feasible to reconstruct box-like bone defect of mandible with the in vivo TE bone.
Mechanical and Phase Stability of Zirconia Toughened Alumina
Authors: Nakanishi Takefumi , Sasaki Megumi , Ikeda Junji , Miyaji Fumiaki , Kondo Makoto
Published: March 2009

The JMM-ZTA, a kind of zirconia-toughened alumina, is a bearing ceramic newly developed for artificial joints. Although it has already been reported that mechanical strength and fracture toughness are higher in the JMM-ZTA than in alumina, the stability of the JMM-ZTA has not been studied in detail yet. In the present study, the stability of the JMM-ZTA with respect to mechanical strength and crystalline phases was examined under hydrothermal environment, and the results were compared with those of alumina. Both the 4-point bending strength and the fraction of monoclinic zirconia unchanged even after the aging test at 121°C for 300 h. These results indicate that the JMM-ZTA possesses quite excellent stability to be used as bearing material of artificial joints.
Research of Herringbone Structure of Fragum Unedo Shell
Authors: Chen Bin , Peng Xiang He , Wu Xin Yan
Published: March 2009

The microstructure of a Fragum unedo shell is observed with a scanning electronic
microscope (SEM). It shows that the shell is a kind of bio-ceramic composite consisting of
aragonite and collagen protein layers. The observation also shows that the aragonite layers consist
of thin and long aragonite sheets. A kind of particular herringbone structure of the aragonite sheets
is found. In the structure, the aragonite sheets in an arbitrary aragonite layer make a crossed angle
against that in its neighboring aragonite layers. Based on the SEM observation the comparative
experiments in the maximum pull-out forces of both the herringbone and conventional 0°-structures
are conducted. It shows that the maximum pull-out force of the herringbone structure is markedly
larger than that of the 0°-structure, and the larger the crossed angle is, the more the maximum
pull-out force of the herringbone structure will increase compared with that of the 0°-structure.
In Vitro and In Vivo Bactericidal Effect of Sol-Gel/Antibiotic Thin Films on Fixation Devices
Authors: Radin Shula , Antoci V. , Hickok N. , Adams Christopher S. , Parvizi Javad , Shapiro I.M. , Ducheyne Paul
Published: March 2009

Beneficial properties of room temperature processed silica sol-gels as resorbable and
biocompatible materials for the controlled release of drugs and macromolecules have been
described before. Recently, it was shown that a thin sol-gel film can be used for the controlled
delivery of antibiotics such as vancomycin. It was also demonstrated that the release and
degradation properties of the sol-gel films can be tailored via processing parameters. In this work,
we evaluated the in vitro and in vivo bactericidal effects of vancomycin-containing thin sol-gel
films applied on Ti-alloy intramedullary nails. Both the in vitro and the in vivo results demonstrate a
pronounced bactericidal effect of the sol-gel/antibiotic films. This study suggests that thin
antibiotic-containing sol-gel film holds great promise for the prevention and treatment of bone
infections.
Bone Formation Effect of HA/β-TCP Composite Powders in Rabbit Calvarial Bone Defects: Histologic Study
Authors: Jang Hyun Seon , Lee Kwang Ho , Jeong Moon Jin , Park Joo Cheol , Kim Heung Joong , Kwon Young Sun , Kim Chong Kwan , Kim Byung Ock
Published: March 2009

This study evaluated the histology results of surgically created bone cavities in the
calvaria of rabbits that were subsequently filled with a HA/ß-TCP composite powder developed in
Korea (Dentium, Korea). Ten young adult rabbits were used. Four defects were surgically produced
in the calvaria of each rabbit. These defects were classified into 4 groups: the control group, no
graft materials; experimental group I, normal saline + graft materials; experimental group II, venous
blood + graft materials; and experimental group III, graft materials only. The defects were
randomly filled with the graft materials. The rabbits were sacrificed with at 1-, 2-, 4-, 6- and 8-
weeks after surgery. The histology specimens were prepared using the general method with H & E
staining at a 6 ㎛ thickness. Histologically, the degree of new bone formation was similar in all
experimental groups. However, for experimental group II, many cells had gathered around the graft
materials 1-week after surgery, and new bone formed slightly faster and than in the other groups.
No bone formation was observed in the control group. Based on histology findings, the new HA/ß-
TCP composite powders appeared to act as a scaffolding material for the regeneration of osseous
defects.
Novel Local Treatment with Paclitaxel-Loaded Hydroxyapatite-Alginate Gels for Spinal Bone Metastases
Authors: Abe Tetsuya , Sakane Masataka , Ikoma Toshiyuki , Tonegawa Toru , Yoshioka Tomonori , Tanaka M. , Ochiai Naoyuki
Published: March 2009

The extent of osseous involvement, particularly spinal cord compression, is directly
correlated with patient survival. To treat metastatic spine cancer, we have developed novel
paclitaxel-loaded hydroxyapatite-alginate gels. In this study, an intraosseous spinal cancer model in
rats was used to investigate the efficacy of local treatment. Ten rats were randomized into two groups,
a local treatment group and a control group. Disease-free time and survival rate in the local treatment
group were significantly longer in this model. (p<0.05)
The Effect of Ceramic Surface Treatments on the Shear Bond Strength of Dental Composite Resin to All-Ceramic Coping Materials
Authors: Kim W.H. , Lee H.J. , Lee Keun Woo , Kim Kwang Mahn , Kim Kyoung Nam , Shim J.S.
Published: March 2009

The purpose of this study was to evaluate the shear bond strength of composite resin to 4
different all-ceramic coping materials with 3 different surface treatments after thermocycling and
without thermocycling. Three different surface treatments - sandblasting with 50 ㎛ alumina particles
(AB); sandblasting with 50 ㎛ alumina particles and acid etching with 4% hydrofluoric acid (AE);
sandblasting with 50 ㎛ alumina particles and 30 ㎛ alumina particles with tribochemical silica
coating (SI) and silane application - were used on four different all-ceramic; Feldspatic ceramic
(Duceram Plus); Lithium disilicate ceramic (IPS Empress2); Alumica ceramic (In-Ceram Alumina);
Zirconia ceramic (Zi-Ceram) - substrates. Shear bond strength of restorative composite resin to
substrate was tested after thermocycling and without thermocycling (n=10). Each specimen was
subjected to a shear load at a crosshead speed of 2 ㎜/min until fracture. Two-way analysis of
variance and Duncan multiple comparison test (α =0.05) were used to analyze the bond strength
values. There were significant differences in the bond strengths for ceramic types (P<.001), surface
treatments (P<.001), and thermocycling (P<.001). The Duncan analysis showed that the Si specimens
had significantly higher bonding strengths than other specimens. The bond strength of composite
resin decreased after thermocycling.
Mechanical Properties and Marginal Fitness of Glass Infiltrated Alumina Core Fabricated from Aqueous-Based Alumina Tape
Authors: Oh Nam Sik , Jeong S.I. , Kim S.H. , Lee Keun Woo , Lee Myung Hyun , Kim I.K. , Kim Dae Joon
Published: March 2009

This study was designed to evaluate mechanical properties and the marginal fitness of
glass infiltrated alumina core fabricated from aqueous alumina tape. Utilizing the automatic Dr.
Blade model (DP-150 of Japan JinChungjungGi manufacturer) fabricated the slurry into 0.5 ㎜
thickness aqueous-based alumina tape. The coefficient of thermal expansion and biaxial flexural
strength of alumina composite produced from alumina tape were investigated. Three upper central
resin incisors were prepared with 90o, 110o, 135o shoulder margin for all-ceramic crown. Individual
tooth model’s impressions were taken 15times each to make epoxy resin die. Cores were made of
alumina tape to each and every dies. Crown setting was done on the epoxy resin dies. The
specimens were evaluated for measuring for marginal gaps of glass infiltrated alumina core
fabricated from aqueous alumina tapes under 180 magnifications with Kan Scope(Sometech
Vision, Korea) was done. The retained measurements were analyzed with Turkey’s Studentized
Range Test for marginal fitness of each specimen. Coefficient of thermal expansion of alumina tape
was 7.5x10-6/°C, and biaxial flexural strength was observed to be 498±32MPa. The marginal fits of
alumina cores made of alumina tapes showed the least marginal gap of 41.5 ㎛ in the 110o shoulder
margin, and increasingly with 135o, 90o shoulder margin. Marginal fitness should be better in angles
larger than 90o.
Ultrafine Grinding of Radix Salvia Miltiorrhiza Particles and the Physicochemical Properties by High Speed Centrifugal Sheering
Authors: Su Y.L. , Fu Zheng Yi , Wang Wei Min , Wang Hang , Wang Yu Cheng , Zhang Jin Yong , Ma P.Y.
Published: March 2009

Radix salvia miltiorrhiza is a commonly used herbal medicine in China, and tanshinone IIA is one of the major active ingredients. Nano Radix salvia miltiorrhiza particles were successfully prepared by high speed centrifugal sheering (HSCS) technology, and the prepared nanoparticles suspension was subsequently spray-dried. The different properties of nano particles and raw powder were systematically studied by laser light scattering granulometric analyzer, TEM, SEM and FTIR. The extractive quantity of tanshinone IIA was determined by high-performance liquid chromatography (HPLC). The results illustrate that raw Radix salvia miltiorrhiza powder can be ultrafinely ground to nanosize within 50min, and the molecular structure of active ingredients doesn’t change after being ground. Furthermore, the active ingredients can dissolve out directly and fully, and the extractive ratio of tanshinone IIA increases 28.6% by HSCS processing. It is valuable to combine nanotechnology and TCM to improve the bioavailability and rapid releasing.
Influence of Different Hydroxyapatite Particles on the Behavior of Highly Malignant Melanoma Cells
Authors: Guo B. , Li B. , Wang Xin Long , Zhang M.X. , Yan N.H. , Zhang Xing Dong
Published: March 2009

The aim of this study is to reveal the response of highly malignant tumor cell to different hydroxyapatite particles. Human’s highly malignant melanoma (MM) cell line A875 is exposed to two kinds of short-rod hydroxyapatite particles. After incubated with hydroxyapatite particles at different time points, the effects of MM cell morphology, proliferation and invasion are evaluated by SEM, MTT, and MMP2 protein immunohistochemistry respectively. SEM figures show that superficial sentus of MM cells reduce; more secretion is found; and smaller HA particles have more obvious effect. At the same time, no statistic difference can be found in MTT assay and MMP2 expression measurement. This study also provides useful information about biosecurity of hydroxyapatite ceramic in transplantation after highly malignant tumor excision.
Evaluation of Osteoblast Responses to Silver-Hydroxyapatite/Titania Nanoparticles In Vitro
Authors: Zhang Jing Chao , Liao Juan , Mo An Chun , Wu Hong Kun , Li Yu Bao , Lv Guo Yu , Li Xiao Yu
Published: March 2009

In the present in vitro study, osteoblasts proliferation, vitality and ultrastructure were investigated when cultured in the presence of silver-hydroxyapatite/titania nanoparticles (nAg_HA/TiO2) compared to HA nanoparticles (nHA) at various concentrations and cell culture without nanoparticles for up to 120 hours. Results confirmed the detrimental influences of both nAg_HA/TiO2 and nHA on osteoblast growth.Cell vitality was slightly higher during the earlier 24h, but after that was inhibited. Both cell proliferation and vitality by addition of nanoparticles were restricted with concentrations of nanoparticles increasing. However, the respiration rates by addition of nanoparticles were showed higher than that of the cell culture without nanoparticles. No remarkable ultrastructure changes were showed in the osteoblasts exposed nanoparticles. The difference in cell proliferation, vitality and ultrastructure between nAg_HA/TiO2 and nHA were insignificant. It was demonstrated that biocompatibility of nAg_HA/TiO2 is almost the same as nHA.
Preparation and Characterization of CaSiO3-Ca3(PO4)2 Composite Bioceramics
Authors: Ni Si Yu , Chang Jiang , Lin Kai Li , Zhai Wan Yin
Published: March 2009

In this study, CaSiO3 (CS)/Ca3(PO4)2 (TCP) composites with 50% CS and 50% TCP sintered at different temperatures (1100oC, 1200oC and 1300oC) were prepared. The formation of bone-like apatite on CS-TCP composites was investigated by soaking the ceramics in simulated body fluid (SBF), and the presence of bone-like apatite layer on the composite surface after soaking in SBF was determined by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The results showed that the bone-like apatite was formed on all the CS-TCP composites sintered at different temperatures after 7 days of immersion. In addition, the degradation of CS-TCP composites prepared at different temperatures was evaluated by measurement of weight loss of the ceramics in Tris-HCl buffer solution at 37oC, and the results showed that there was no difference in degradation rate between the samples. In vitro cell experiments indicated that the osteoblasts proliferated faster on the CS-TCP ceramics sintered at higher temperature, and cells on the CS-TCP ceramics sintered at 1300oC showed highest proliferation rate. These results provide valuable information for designing CS-TCP composite bioceramics for bone regeneration applications.
Improvement of Microstructure of Bovine Hydroxyapatite with Yttria
Authors: Ozyegin L.S. , Salman S. , Oktar Faik N. , Agathopoulos Simeon , Meydanoglu Onur , Akesi S. , Yukler I.
Published: March 2009

Composites of calcinated bovine bone derived hydroxyapatite (HA) with 0.5 and 1 wt% Y2O3 were prepared by sintering. Money and time saving feature the production of HA from natural sources. In this study, results of scanning electron microscopy (SEM) and X-ray diffraction analysis aimed to interpret the results of measurements of densification, microhardness, and compression strength of the produced composites. The best mechanical properties were achieved after sintering at 1200°C for compressive strength and 1300°C for microhardness. The results are in a fair agreement with densification measurements and microstructure analysis.
Preparation and Characterization of Porous β-TCP/PLLA Composites with High β-TCP Content
Authors: Liu Hui Bin , Gao Yan Bo , Miao Shun Dong , Weng Wen Jian , Cheng Kui , Du Pi Yi , Shen Ge , Han Gao Rong
Published: March 2009

Porous β-tricalcium phosphate (β-TCP)/ Poly L-lactic acid (PLLA) composites were
prepared by thermally induced phase separation method. The results showed that the composite had
an interconnected pore structure with ～200μm macropores. The inorganic particle content in the
composites varied from 50% to 80% and these particles were homogeneously dispersed in PLLA
matrix. The composites obtained in this study could act as a promising scaffold for bone tissue
engineering because of the pore structure and the mechanical properties.
The Behavior of SiC Films Fabricated by Hybrid Laser-Magnetron Deposition after Immersion
Authors: Badea Nicoleta Maria , Jelinek M. , Tite T. , Prodana Mariana , Campean A. , Demetrescu Ioana
Published: March 2009

The in-vitro bioactivity of SiC growing using the innovative hybrid laser-magnetron
deposition technique was investigated. The biological response has been analysed after being
immersed in a human blood plasma solution for 10 days. Surface analysis by SEM microscopy
shows clearly an adsorption process after immersion. The products formed are mainly attributed to
a rich-calcium phosphate and silica-complexes layers. Citotoxicity test shows a normal phenotype
of fibroblast cell culture on SiC and MTT assay indicates an increased viability of cells around 15%
after only one day of immersion. Results obtained are supported by FTIR analysis. Strong changes
in the absorbance of bands after immersion are observed, which indicates a strong bioactivity of
SiC.
Bloodcompatibility Improvement of Titanium Oxide Film Modified by Hydrogen Plasma Reduction
Authors: Xu Y. , Huang Nan , Sun Hong
Published: March 2009

In this work, nonstoicheometric titanium oxide film on silicon matrix was prepared by unbalanced reactive pulsed magnetron sputtering /hydrogen plasma reduction method. The film chemical composition was analyzed by X-ray diffraction and X-ray photoelectron spectroscopy (XPS). The XRD patterns of the prepared films showed that titanium oxide films possess the single phase rutile structure . the XPS spectra of the film displayed that the valence state of Ti is Ti4+, Ti3+ and Ti2+ respectively and the films were nonstoichiomeric Ti-O film. The evidence showed that isolated oxygen exist in films. Ti/O ratio of Ti-O film from the XPS data vary with depth under different reduction temperature and time. And it corresponded with platelet adhesion tests of Ti-O film in vitro. Antithrombotic property of reduced titanium oxide thin films was examined by platelet adhesion tests. The results showed that the Ti-O films with lower non-stoicheometrical extent posses the better anticoagulation property than stoichiomeric TiO2 film and the Ti-O films with higher non-stoicheometrical extent. Hence hydrogen introducing is an effective way to improve the bloodcompatibility of titanium oxide film.
Preparation of Titania Films on Implant Titanium by Electron Cyclotron Resonance Plasma Oxidation
Authors: Masumoto Hiroshi , Goto Takashi , Honda Yoshitomo , Suzuki Osamu , Sasaki Keiichi
Published: March 2009

Titania (TiO2) thin films were fabricated on titanium (Ti) substrates at low temperatures
by electron cyclotron resonance (ECR) plasma oxidation, and the relationship among the
oxidization conditions, crystal structure and osteoconductive property was investigated. Amorphous
TiO2 films were obtained below 300°C and crystallized rutile-type TiO2 films were obtained above
400°C. The XRD peak intensity of rutile TiO2 increased with increasing oxidation temperature.
Mixtures of octacalcium phosphate (OCP) and Dicalcium phosphate dihydrate (DCPD) peaks were
observed after calcification. The intensity of the OCP and DCPD peaks after calcification increased
with increasing oxidation temperature. The ECR plasma was significantly effective to prepare
crystallized TiO2 films at low temperatures.
Fabrication of Bioactive HA/Ti Composite Coating by Laser Cladding
Authors: Yang Sen , Man Hau Chung
Published: March 2009

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.
The Bevavior of Ceramic Coating on Titanium Using Chemical and Electrochemical Deposition
Authors: Ionita D. , Bojin D. , Demetrescu Ioana
Published: March 2009

The goal of this paper is elaboration and characterization of chemical and
electrochemical phosphate deposition on titanium. The behavior of the bioactive coating was
evaluated using electrochemical methods (open circuit potential, cyclic voltametry) and
spectroscopy (FTIR and atomic adsorbtion spectroscopy).
Biomimetic Synthesis of a Strontium-Substituted Apatite Coating Grown on Ti6Al4V Substrate
Authors: Oliveira A.L. , Reis Rui L. , Li Pan Jian
Published: March 2009

In this study we explore the possibility of incorporating Sr into nano-apatite coatings prepared by a solution-derived biomimetic methodology for coating titanium based implants. The way this element is incorporated in the apatite structure and its effects on the stereochemistry and morphology of the resulting apatite layers were investigated, as well as the resulting mineralization kinetics. The presence of Sr in solution induced an inhibitory effect on mineralization, leading to a decrease in the thickness of the mineral layers. This ion was incorporated in the apatite structure through a substitution mechanism by replacing Ca in the crystal lattice. The obtained Sr-substituted biomimetic coatings are expected to enhance bone formation and osteointegration.
Mineralization Behavior of Bioactive Ceramic Coatings Formed by Micro-Arc Oxidation on Titanium
Authors: Nan Kai Hui , Pei G.X.
Published: March 2009

Titanium oxide films were obtained by MAO at the applied voltages of 250-550V and
their bio-mineralization behavior was investigated. The films were composed mainly of TiO2 phases
in the form of anatase and rutile and enriched with Ca and P elements in the form of CaTiO3 and
amorphous calcium phosphate. Their bio-mineralization behavior was evaluated in a simulated
body fluid (SBF). After immersed in SBF for 72 h, white mineralized layers were observed on the
samples obtained at high voltages. The bio-mineralized rate of samples increased with the applied
voltages, which resulted in the difference on morphology of different samples. The structure and
composition of the films have an important effect on their bio-mineralization behavior.
Preparation of Hydroxyapatite / Titania Double Layer Coating on Poly-I-lactide due to Hydrolysis of Titanium Tetrachloride
Authors: Liu Jin Fang , Hayakawa Satoshi , Tsuru Kanji , Jiang Jian Zhong , Osaka Akiyoshi
Published: March 2009

Rutile films were deposited on poly-l-lactide (PLLA) substrates using 0.5 M titanium
tetrachloride aqueous solution at 40 °C for 72 h. The rutile films exhibited excellent in vitro
bioactivity as they induced apatite deposition in a simulated body fluid (SBF) within 3 days. This
simple treatment provided an effective route to synthesize bioactive and biodegradable scaffolds.
Biocompatibility of Cerium Oxide Films Synthesized by Dual Plasma Deposition
Authors: Jing Feng Juan , Wang Lu , Liu Y.W. , Cheng J.Y. , Leng Yong Xiang , Fu R.K.Y. , Zhao X.B. , Chu Paul K. , Huang Nan
Published: March 2009

Cerium oxide films have been fabricated using dual plasma deposition. X-ray diffraction. (XRD) reveals a crystalline phase and X-ray photoelectron spectroscopy (XPS) shows that La exists predominantly in the +4 oxidation state. The activated partial thromboplastin time is longer than that of blood plasma and stainless steel. Furthermore, the numbers of adhered, aggregated and morphologically changed platelets are reduced compared to low-temperature isotropic carbon (LTIC). HUVEC cells exhibit good adhesion and proliferation behavior on cerium oxide films. This study suggests rare earth oxide films are potential blood-contacting biomedical materials.
Preparation of Bone-Like Microstructured β-TCP/Collagen Layer on Fluoridated Hydroxyapatite Coating
Authors: Zhou Ja Bei , Weng Wen Jian , Cheng Kui , Song Chen Lu , Du Pi Yi , Shen Ge , Han Gao Rong
Published: March 2009

Bone-Like Microstructured β-TCP/Collagen Layer on Fluoridated Hydroxyapatite
Coating, which could able to create a biodegradation layer with enhancing bone formation, was
prepared in wet synthesis. The formation of the layer was characterized and discussed.
Research on the Layered Microstructure of Shankbone
Authors: Chen Bin , Wu Xin Yan , Peng Xiang He
Published: March 2009

Bone is a kind of biomaterial in nature. It behaves favorable strength, stiffness and fracture toughness which are closely related to its fine microstructure. SEM observation on a shankbone shows that the bone is a kind of natural bioceramic composite consisted of hydroxyapatite layers and collagen matrix. The observation also shows that the hydroxyapatite layers consist of many hydroxyapatite sheets and are arranged in a parallel distribution. The fracture toughness of the bone is analyzed based on the representative model of the microstructure of the bone and the idea of maximum pullout force. The analytical result shows that the long and thin shape as well as the parallel distribution of the hydroxyapatite sheets improves the maximum pullout force of the sheets and the fracture toughness of the bone.
Preparation of Caclium Phosphate Paste Composites with Demineralized Bone Matrix
Authors: Lee Kang Yong , Lee Y.W. , Park M. , Kim Hyun Min , Lee J.H. , Kim K.T. , Han J.S. , Oh K.S.
Published: March 2009

In this study, we attempted preparation and assessments of composite pastes of demineralized bone matrix (DBM) and calcium phosphate cement (CPC). While the composite pastes presented self-setting behavior up to a certain DBM content without significant differences in setting time, temperature increase and phase transformation, compressive strength and injection capability decreased in general with the DBM content. The DBM particulates were observed to uniformly disperse in the composite cross-sections, suggesting a new model of bioactive paste with tissue regenerative function.
Development of a New Injectable Calcium Phosphate Cement That Contains Modified Starch
Authors: Chen Ling , Xiang Hong , Li Xiao Xi , Ye Jian Dong , Wang Xiu Peng , Li Lin , Zhang Xi Mei
Published: March 2009

In this study modified starch were used as anti-washout promoters of injectable calcium phosphate cement (CPC) and the effects of the modified starch on the injectability, anti-washout performance, setting time, compressive strength, phase evolution and microstructure of this cement were investigated. The injectability of the cement was improved by adding the modified starch (0.5-2.0%). After mixing with modified starch (0.5-2.0%), the cement showed better anti-washout performance than that without modified starch after immersed and shaken in SBF. Especially, when the content of the modified starch was 1.0%, the remaining percentage of the cement was reached to 92.6%, but only 5.9% of the CPC paste remained and set for the sample without modified starch after shaken for 2 hrs. The compressive strength of cements significantly increased from 44 MPa to 54 MPa when 0.5% of modified starch was added. And a slight increase on the mechanical strength can be observed for other concentrations. Powder X-ray diffraction analysis revealed no significant difference for the conversion of the cement to hydroxyapatite for any concentrations of modified starches. The influence of the modified starch on the microstructure of the set cement was also studied. The results showed the modified starch would reduce the acicular crystal size of hydroxyapatite accompanied with little flaky crystals generation and made a compact structure. It is concluded that modified starch, a suitable anti-washout promoter, improved the performance of CPC.
Bimodal Porous Bi-Phasic Calcium Phosphate Ceramics and Its Dissolution in SBF Solution
Authors: Zhang Y. , Yokogawa Yoshiyuki , Kameyama Tetsuya
Published: March 2009

Biphasic calcium phosphate (BCP) ceramics, a mixture of hydroxyapatite (HAp) and
beta-tricalcium phosphate (β-TCP), of varying HAp/β-TCP ratios were prepared from fine powders.
Porous BCP ceramic materials with HAp/β-TCP weight rations of 20/80, 40/60, and 80/20 were
prepared. In this study, the bioactivity is reduced at a larger HAp content rate, which is likely
related to the high driving pore for the formation of a new phase, and the reaction rate was
proportional to the β-TCP. The porous BCP ceramics having a bigger porosity rate can easily under
up dissolution. The powder having a larger β-TCP content rate can easily generate a new phase. The
dissolution results confirmed that the biodegradation of calcium phosphate ceramics could be
controlled by simply adjusting the amount of HAp or β-TCP in the ceramics and porosity rate.
Segementation of X-Ray Microtomography Data of Porous Scaffold
Authors: Zou Shuo , Best Serena , Bonfield William
Published: March 2009

Computerized X-ray micro tomography (micro CT) is a powerful technique for studying
the structure and properties of porous scaffold. A variety of sample parameters can be studied using
a single micro CT scan [1]. In general a segmented data set is a required for most quantitative
analysis. However, segmentation of CT data can be difficult due to the artifacts in micro CT
images such as blurred interfaces due to the machine contrast transfer function and the partial
volume effect. Therefore the segmentation can be biased and prone to errors. Many methods have
been developed to improve segmentation, however the interface problem has not been solved
perfectly [2]. Porous scaffolds suffer from these effects because of their high surface to volume
ratio and hence large interface. In this paper we discuss the interface problem in detail and
demonstrate the effect of voxel size on the histograms of CT images of porous scaffold as well as a
thresholding method based on 2 dimensional histogram is also presented. The potential of this
method in more complicated scenarios such as 3-phase system is currently being investigated [3].
In Vitro Evaluation of Porous Biphasic Scaffolds
Authors: Santos Silvia R. A. , Rossi Antonella M. , Andrade L.R. , Prado da Silva Marcelo Henrique
Published: March 2009

In the present study, two methods for the production of three-dimensional scaffolds made
of bioactive ceramics are presented. Depending on the method, the final product can be composed by
pure hydroxyapatite or biphasic: hydroxiapatite + tricalcium phosphate. Bioactivity tests showed that
all scaffolds are bioactive. Preliminary studies with adipose stem cells indicated biocompatibility of
both scaffolds.
Structure and Antibacterial Properties of Ag-Doped TiO2 Porous Materials
Authors: Liu Hai Rong , Lin Yi , Ye Rei Fang , Song Li , Chen Qi
Published: March 2009

Antibacterial Ag-doped TiO2 porous monolithics were firstly prepared by hybridization of
polyethylene glycol, Ti(OC4H9)4 and AgNO3 via sol-gel method following by heat-treatment to
remove the organic components. Thermogravimeter−differential thermal analysis, pore structure,
infrared spectra, ultraviolet−visible spectra, release speed of silver ions into 30°C water and
antibacterial properties of Ag-doped TiO2 samples made at different temperature were studied. The
results showed that anatase phase and uniform pore structure can be formed after heated at 500°C.
Ag+ ions from the samples heated at 500°C were stably released into water at 30°C up to 14 days. The
material treated at 500°C has the best antibacterial property and can restrain Escherichia coli
effectively.
Quantitative Assessment of Crack-Tip Stress Field in Semiconductor GaN Using Electrostimulated Piezo-Spectroscopy
Authors: Pezzotti Giuseppe
Published: March 2009

The piezo-spectroscopic (PS) effect, which may be defined as the shift in wavelength of a spectroscopic transition in a solid in response to an applied strain or stress, may occur both in crystalline and in amorphous structures, regardless of the particular spectroscopic transition involved (e.g., luminescence or Raman spectrum), and independent of the specific mechanism of luminescence emission (i.e., including spectra generated from substitutional impurities, optically active point defects, etc.). The PS effect can be monitored on electro-stimulated spectra when the scale on which the needed characterization lie is of a nanometer length. This effect, being a physical property of the studied material, should be calibrated case by case. The high scanning speed (and computer control) of the electron beam, which can be easily obtained with scan coils, is unsurpassed. Since the most recently developed optoelectronic devices have active areas of submicron dimensions and many of them less than 100 nm, no obvious choice is left but urgently developing an electro-stimulated probe for nano-scale residual stress assessments. In this paper, we show the feasibility of nano-scale stress assessments in the neighborhood of the tip of a crack propagating in GaN, selected as a paradigm semiconductor material.
Preparation of Sulphoaluminate-Alite Composite Mineralogical Phase Cement Clinker from High Alumina Fly Ash
Authors: Li Jin Hong , Ma Hong Wen , Zhao Hong Wei
Published: March 2009

Sulphoaluminate-alite cement (SAAC) was successfully prepared from high alumina fly
ash. XRD analysis indicated that the optimal mineralogical phase of cement clinker was obtained
under condition of MG=1.05, MS =0.95 at 1300oC, and C4A3 S reached the strongest intensity and
is 58.73% in the phase of calcined clinckers. SEM observation showed that C4A3 S are well
developed into regular diamond/hexagon-shaped crystal with the size of 1~3.5 μm in the clinker.
Hydrated clinker exhibited its new formed dominant phases in AFt, C-S-H and Afm. Pillar shaped
AFt and sheet shaped AFm coexisted among the colloidal C-S-H substrate. It is demonstrated that
the prepared cement shows a compressive strength of 27 MPa (1d), 36 MPa (3d), 49 MPa (28d),
and flexural strength of 5.9 MPa (1d), 5.9 MPa (3d), 6.1 MPa (28d), indicated that the hydration
product owned a good mechanical strength at early ages and increased steadily in the later stages.
Preparation and Microstructure of Bauxite Ceramic Microsphere
Authors: Cheng Xiao Su , Zeng Ling Ke , Li Xiu Yan , Sheng Wen Yan , Shui An Ze , Liu Ze Hao , Zhang Ying Yuan , Wang Yue , Wang Yong Zhao
Published: March 2009

In this paper, microspheres were prepared by using Chinese bauxite as raw materials through
centrifugal spray drying method. The microstructure and composition of ceramic microsphere were
investigated by X-ray diffraction, scanning electron microscope and X-ray energy spectrum. The particle
size was 10~100#m. The XRD analysis reveals that the main crystalline phase of the ceramic microsphere
were α-Al2O3 and mullite (3Al2O3•2SiO2). The Al2O3 content (chemical composition) of the microspheres
was little more than 70%, and the molar ratio of Al2O3/SiO2 was near to the molar ratio of alumina
and silica of mullite.
Preparation of Amorphous Si-B-C-N Powders and Nano-Sized Ceramics
Authors: Yang Zhi Hua , Zhou Yu , Jia De Chang , Yu Chang Qing , Meng Qing Chang , Ouyang Jia Hu
Published: March 2009

Amorphous nano-sized silicoboron carbonitride (Si-B-C-N) powders with average grain size
<50 nm were fabricated by high energy shaker mill using hexagonal boron nitride, graphite and amorphous
silicon powders as starting materials. The powders were consolidated by spark plasma sintering at
1900° and 1950°C. Amorphous phase were partially retained in ceramic sintered at 1900°C. For ceramic
sintered at 1950°C, amorphous Si-B-C-N ceramic transferred to hexagonal BN and cubic SiC.
Microstructure of Cf/SiC Composite with Precursor of Hexamethyldisilazane by Chemical Vapor Infiltration
Authors: Yuan Ming , Huang Zheng Ren , Dong Shao Ming , Jiang Dong Liang
Published: March 2009

A method of waved-thermal field chemical vapor infiltration was introduced. And interphases of silicon carbide layer and carbon layer were processed via the route. The preforms with the interfacial coatings were densified by method of forced-flow thermal-gradient chemical vapor infiltration (FCVI) employing hexamethyldisilazane (HMDS) as precursor material of the matrix. The matrix of the composites annealed at 1400°C consists of nano-polycrystalline silicon carbide. The configuration of fracture surface was observed by scanning electronic microscopy (SEM). The interphases behaved successfully as mechanical fuse for the reinforcing fibers.
Composition, Structure and Properties of Low Oxygen Content SiC Fibers
Authors: Yang Da Xiang , Song Yong Cai , Mao Xian He , Li Wei
Published: March 2009

A new curing method, chemical vapour curing (CVC) for polycarbosilane (PCS) fibers using
unsaturated hydrocarbon (cyclohexene) vapour was studied. The low oxygen content SiC fibers were
prepared and when the oxygen content in fibers was lower than 4.0%, the maximum tensile strength
reached to 3.8GPa. The relationship between the tensile strength and the oxygen content of the fibers was
investigated. The structure and composition of SiC fibers were also characterized by element analysis,
FT-IR, XRD and XPS. Compared with that by air curing method, SiC fibers with less oxygen and better
mechanical properties were prepared by CVC method.
Mechanical Properties of Al2TiO5 Ceramics
Authors: Chen Chun Hong , Awaji Hideo
Published: March 2009

Aluminum titanate ceramics (Al2TiO5) is a synthetic ceramic material of potential interest for
many structural applications. A critical feature, which greatly limits the mechanical properties of polycrystalline
Al2TiO5, is considerable intergranular microcracking, which occurs due to the high thermal
anisotropy of individual grains. In this study, the temperature dependencies of mechanical properties were
discussed along with the microstructure observation. Both of fracture strength and fracture toughness
increased considerably with increasing the temperature. These phenomena were explained on the basis of
the stress redistribution and unique microscopic feature on the fracture surface of aluminum titanate
ceramics. The experimental results also revealed that the repeated heat treatments resulted in the change
of fracture strength and fracture toughness due to the stress redistribution in the Al2TiO5 matrix.
Preparation and Properties of BN-SiO2 Composite Ceramics
Authors: Zhai Hua Zhang , Cai Hong Nian , Yang Xiao Zhan , Li Jian Bao , Guo Gang Feng , Cao Chuan Bao
Published: March 2009

A series of BN-SiO2 composite ceramics with high relative densities have been fabricated by hot pressing of a mixture of hexagonal boron nitride powder and silica sol. X-ray diffraction (XRD) results show that silica are distributed in the BN matrix as noncrystalline state. Microstructure of as-sintered composite ceramics is observed by scanning electron microscopy (SEM). The influence of the secondary phase on the mechanical properties is studied by varying the silica content from 10 wt% up to 40 wt%. Dielectric properties of composite ceramics are also measured from 1 MHz to 2.0 GHz.
In Vivo Behavior of Injectable Fast-Setting Calcium Phosphate Cement
Authors: Dong Li Min , Wang Chen , Liu Rui , Tian Jie Mo , Zan Qing Feng
Published: March 2009

The in vivo study was performed to evaluate the biocompatibility and osteogenous ability of injectable fast-setting calcium phosphate cement (CPC). Eighteen four-week-old New Zealand white rabbits were divided into six groups randomly, three in each group. According to the principle of selfcontrast at the same time, cavities of 5mm in diameter and 6mm in depth were drilled in femoral condyle of rabbits. The materials were implanted into cavities of the left leg, the right leg as the blank control group. Rabbits were sacrificed at 2, 4, 8, 12, 16 and 24 weeks after surgery. The microstructure of specimens was observed using ESEM. The results showed that injectable fast-setting CPC had good fluidity and plasticity; it could be injected into bone defects and fast-set in situ. The start setting time was 5-8 min and the compressive strength was 25-30 MPa. The CPC had good biocompatibility and osteoconductivity, and benefited to the repair of bone defects.
TEM Analysis on Bio-Functional Gradient Hydroxyapatite/ZrO2 Coatings
Authors: Ning Cheng Yun , Wang Ying Jun , Chen Xiao Feng , Ye Jian Dong , Wu Gang , Zhao Na Ru
Published: March 2009

In the present study, bioactive functional gradient coatings were prepared using net-energy
controlled plasma spraying technology. The microstructure and phases of the bioactive functional gradient
coating were examined by means of transmission electron microscope, scanning electron microscopy
and X-ray diffraction. The results revealed that: (1) as-sprayed coatings contained a large amount of
amorphous phases and some nano-sized HA crystals formed during rapid solidification, (2) surface of the
coating was very rough with different-sized micropores, and the gradient layer was much denser which
firmly bonded to the substrate without gaps and obvious interface between the coating and the substrate
Simulation In Vitro of Subsonic Flame Sprayed Titanium/Biological Glass Composite Coating
Authors: Li Mu Qin , Yang Shuo , Wang Jian Ping , Yang Shi Qin , Yang Gang Lei
Published: March 2009

20wt% bioactive glass was added to the pure titanium power by means of subsonic flame spraying. Soak test in vitro was performed with the sprayed samples after heat treatment, and the polarization curve was determined. The result shows that pH of the solution varied during the 60 h immersion of the coating in the simulated body fluid. This related to the fact that TiO2.CaTi4O9.NaTiO2 etc were dissolved and precipitated in the coating. With different immersion time, the coating weight increased first, and then decreased. The self-corrosion potential and morphology of the coating were influenced by different polarization corrosion rate. When the polarization corrosion rate was low, it contributed to the growth of bone-like apatite, and then the corrosion was restrained. In simulated body fluid, absorption, dissolution, and the formation and growth of new phases took place in the coating. Bone-like apatite may form on the coating surface, which indicates the excellent biocompatibility of 8Ti2G bio-composite coating.
Bisphosphonate Pamidronate Modifying Hydroxyapatite Bioceramics for Hard Tissue Repair
Authors: Luo En , Hu J. , Li J.H. , He Gang , Wei S.C. , Cui Jun
Published: March 2009

This study is to investigate the method of pamidronate modifying HA bioceramics and the effect of pamidronate modifying HA bioceramics on the osteoblastic cells. Pamidronate was immobilized on the surface of porous HA bioceramics for bone scaffold by chelating. The outermost layer of the specimens was analyzed by XPS and FT-IR. The depth profile was investigated by the argon-ion sputtering method. The MC3T3-E1 osteoblastic cells were inoculated and cultured on the scaffolds. SEM and phase contrast microscope observation of the cells, MTT test and ALP activity test evaluated the cell attachment, proliferation and activity on the scaffolds. Characteristic peaks in XPS and FT-IR spectra indicated pamidronate being immobilized on the surface of the bioceramics. The cell culture test indicated that the cells actively proliferated on the scaffolds. There was no significant difference between the ALP activity of the cells cultured for 1d, 3d and 7d on PAM-HA and that of the controls. The result indicated that PAM-HA bioceramics had favorable cytocompatibility to be used as bone scaffold with potential ability to improve osteogenesis.
Microstructure and Properties of In Situ Synthesis of TiC Particle Reinforced Composite Coating by Induction Cladding
Authors: Wang Zhen Ting , Wang Yong Dong
Published: March 2009

A composite coating with TiC Particle of embedded in nickel based alloy has been in-situ
synthesized by induction cladding a precursor mixture of nickel based alloy powder, titanium and
graphite powders. The results showed that the composite coating has good metallurgical bonding with the
substrate as well as there is a good wettability between the reinforcement TiC and the coating matrix. The
microstructure of the composite coating is mainly composed of γ-Ni dendrite, a small amount of M23C6,
and dispersed TiC particle. The volume fraction of TiC particle increases with increasing of volume
fraction of titanium and graphite. The microhardness gradually increased from the bottom to the top of the
composite coating. The average microhardness of the composite coating is HV0.21200, 5 times larger than
that of the 16Mn steel substrate.
Phase Structure and Electrical Properties of Bi1/2Na1/2TiO3-KNbO3 Lead-Free Piezoelectric Ceramics
Authors: Lu Wen Zhong , Fan Gui Fen , Wang Xiao Hong , Liang Fei
Published: March 2009

Lead-free (1-x) Bi1/2Na1/2TiO3-xKNbO3 (x=0, 0.01, 0.02, 0.04, 0.05 0.06, 0.10) piezoelectric
ceramics were prepared by conventional ceramics fabrication technique. The results of x-ray diffraction
(XRD) show that these ceramics possess pure perovskite structures with a symmetry transition from
rhombohedral to cubic at about x = 0.05. The piezoelectric properties of these ceramics were reported and
found to reach extreme values at x = 0.04 with d33 up to 113pC/N and kp up to 22%. The temperature
dependence of dielectric constant and dielectric loss of these ceramics were also investigated. The Curie
temperature and depolarization temperature dropped with the increase of KNbO3 amount.
Preparation of SiO2-TiO2 Films of High Photo-Catalytic Activity in the Electric Field Heating-Treatment
Authors: Zhou Feng , Zhang Hui Chen , Liang Kai Ming
Published: March 2009

In this paper the Li+, Sb3+-doped SiO2-TiO2 thin films, which were heat-treated with an applied electric field, were prepared by sol-gel dip coating. The crystallization of the thin films in the electric field heating-treatment was studied by X-ray diffraction (XRD) and atomic force microscope (AFM). The photo-catalytic activity of SiO2-TiO2 films was studied under the condition of an electric field heating-treatment and mixing with some additive such as Li+ and Sb3+. Finally, studies on photo-catalytic degradation showed that the Li+, Sb3+-doped SiO2-TiO2 films on the quartz glass, of high photo-catalytic activity, were successfully obtained in the electric field heating-treatment.