The Bisphosphonate Clodronate Modifying Hydroxyapatite Bioceramics for Bone Scaffold

1Introduction Variousbiomaterialsareincreasinglyusedasbone substitutesinorthopedicsurgery,oralandmaxillo facial surgery.Toserveasabonesubstitute,thematerialmust bebiocompatible,osteoconductive,andosteointegrative.Hydroxyapatite(HA)hasfavorablebiocompatibi…     

修复长骨大段骨缺损的ZrO2增韧HA陶瓷研究

研究了用于修复长骨大段骨缺损的ZrO2增韧羟基磷灰石复合生物陶瓷。采用XRD及SEM测定了材料的矿物组成与显微结构，并测试了材料的理化性能。分析了材料的结构和性能并初步确定了较为理想的配方。     

用于大段骨缺损修复的TCP／HA基多孔生物陶瓷的研制

探索了ＴＣＰ／ＨＡ基多孔生物陶瓷的配料组成，确定了较优制备条件，并通过Ｘ－射线衍射分析及ＳＥＭ等揭示了材料的矿物组成及显微结构。制备出有望用于临床的多孔生物陶瓷材料     

TCP－HA－BG多孔复合生物陶瓷降解性能研究

从物理化学、物质结构、热力学、断裂力学等观点出发，远用原子吸收光谱电子计算机图象分析仪等手段，考察了该系统复合陶瓷的体外静、动态溶解性能及动物体内降解性能，分析了影响材料降解能力的各种内在及外界因素。得出材料的降解机理主要是液体介导过程。     

Drug Release Characteristics of Hydroxyapatite Bone Cement

1Introduction Hydroxyapatitebonecement(HAC)isanewlyde velopedartificialbonematerialusedforbonedefects.Itisaself settingandnonceramicbonematerial,whichismadeofcalciumphosphatepowderanddilutedacidor isotonicsaline.HAChasaverypracticalcharacteristic:itcanbes…     

Composition and Structure of Fibrous Hydroxyapatite Growth on an Injectale Bone Tissue Engineering Scaffolds Material

Fibrous hydroxyapatite （ HA ） wns grown upwards from the crosslinked unsaturated polyphosphoester（ UPPE ） which was used us an injectable bone tissue engineering scaffolds. Composition of fibrous HA was determined by FT- IR, XRD and EDX, which suggested that the fibrous HA was calcium deficient carbonated apatitie with low crystallinity. SEM micrographs indicated that the fibrous HA had a hollow tubing structure and tube wall wus a flakelike assembly. The fibre with poor mechanical property arm with a growth rate about 0. 5 mm/min reached several centimeters in length after 2 hours. The growth was at the tip of the fibre suggested that the procedure of forming fibrous HA was as follows ： Co^2＋ ions were firstly incorporated into the crosslinked UPPE by dipping in Ca^2＋ solution, then supplied through micropores of the material reacted with PO4^3- ions to form α small tuhe , the osmotic pressure or capillary force lead the Ca^2＋ continuously gushed oat into the PO4^3- solution, thus fibrous HA was obtained.     

Composition and Structure of Fibrous Hydroxyapatite Growth on an Injectale Bone Tissue Engineering Scaffolds Material

1Introduction Thetreatmentofbonedefectsinducedbyinjuryor pathologicalchangecouldbenefitfrombiocompatiblema terialsbasedonbiodegradablepolymerthatassistinthe boneregeneration.Thesepolymersareverypromisingasa temporarystabilizationforaugmentationoffracturef…     

磷酸单酯偶联剂对羟基磷灰石的表面改性研究

通过熔化共混等工艺制备了羟基磷灰石(HA)粉末的磷酸单酯(PL)偶联剂表面改性复合物。用水的浸润高度、疏水性保持率、润湿角等手段对改性粉末的性能进行了表征，用IR图谱对复合物的结构进行了分析。对HA粉末的煅烧温度、改性粉末的偶联剂加量对改性效果的影响以及改性粉末的稳定性进行了研究，初步探讨了偶联剂对粉末表面改性的作用机理。结果表明PL是一种高效的表面改性偶联剂，与羟基磷灰石的反应活性高，能与羟基磷灰石形成稳固的键合。所制备的HA—PL复合物具有良好的疏水性，稳定性。用此改性HA粉末与高聚物共混，制取HA／高聚物复合材料时将可能大大改善HA与高聚物的结合性能。     

纳米羟基磷灰石的表面改性及其细胞毒性的研究

利用聚乙烯亚胺(PEI)和聚丙烯酸钠(PAA)对纳米羟基磷灰石(nHA)进行表面改性,并从影响细胞增殖和凋亡的角度出发,采用四唑盐比色法(MTT法)和荧光染色法对改性后的纳米羟基磷灰石颗粒进行了体外细胞毒性评价。结果表明:利用PEI和PAA可以显著地改变nHA的表面电性;而细胞的毒性与其共培养的颗粒表面电性、浓度和共培养时间有关,在较低浓度下,没有经过表面改性的纳米羟基磷灰石颗粒具有最好的细胞相容性,其细胞毒性为0级,PEI改性的纳米颗粒的细胞相容性最差,而PAA改性的纳米颗粒的细胞相容性介于二者之间。初步证明了表面电性对材料细胞毒性的影响,即正电性纳米颗粒的细胞毒性较大。     

利用Fe2+对羟基磷灰石粉末表面改性的研究

因其独特的化学组分和晶体结构,羟基磷灰石(HA)可通过引入金属离子实现表面改性,即将制备的HA粉末放入含有二价铁离子的溶液中,Ca²⁺与具有小离子半径的Fe²⁺完成离子交换.对改性粉末进行表征后发现,HA粉末的表面电势、OH和PO4基团的伸缩振动频率以及(00l)晶面的间距都发生了变化.另外,在含油酸钠的溶液中Fe²⁺改性的HA粉末与阴离子电解质间的化学键合能力大大下降.本研究可模拟人体骨骼和牙齿中的Ca²⁺被体内循环系统中Fe²⁺取代的情况.     

Preparation and Behaviour of New Materials for Percutaneous Access

1Introduction HAbioceramicsarewidelyusedinclinic,buttheir applicationsaresometimeslimitedowingtolowstrengthof thematerial.Ontheotherhand,theimplantedmaterial ofpercutaneousaccessandbodytissueswillreactmutual lyintheextremelycomplicatedphysiologycircumstan…     

钛基体上化学法制备羟基磷灰石涂层的优化工艺研究

研究通过简单的化学反应法在钛基体上制备羟基磷灰石（HA）涂层．钛板经粗糙化、酸蚀、清洗、干燥以后,在5mol／L的NaOH溶液中60℃处理24h,然后在饱和Ca（0H）,溶液中进行预钙化处理,接着在过饱和Ca3（PO4）2溶液中进行沉积处理,最后在0．1mol／L的NaOH溶液中60℃对沉积层进行48h的后处理,制得一定厚度的、Ca／P=1．67的羟基磷灰石涂层．用扫描电镜、能谱仪和X射线衍射仪对涂层进行显微组织观察、测定涂层厚度、并进行物相和元素分析．本研究对使用的各种溶液的浓度、处理温度和时间均进行了优化．     

Surface Modification of Hydroxyapatite by Using γ-aminopropyl Silane

Surface modification of hydroxyapatite( HA) powder was performed with r-aminopropyi silane in toluent solvent. The modification effects were characterized by using XPS and FT-IR methods . The results indicated that the P2p electron binding energy of the modified HA decreases 0.4 eV compared to that of HA . Furthermore , a new peak, 998cm-1 absorption appeared in IR differential spectra of modified HA and HA, which is due to a stretching vibration of structure P-O-Si, meaning that a direct covalent bonding between hydroxyl group on HA surface and the organic silane molecule was realized after modification, and the chemical bonding type was P- O-Si. The formation of the above structure suggested that the more effective interfacial adhesion between the modified HA and polymer matrix could be carried out.     

Enhanced Interfacial Adhesion in HDPE/HA Composites by Surface Modification of HA Particles via in situ Polymerization and Copolymerization

1Introduction Particulatehydroxyapatite(HA)reinforcedhigh densitypolyethylene(HDPE)compositehasbeendevel opedsinceearly1980sasananaloguematerialforbone replacement[14].Thecombinationofbioactive,stiff,butbrittleHA,andlowelasticmodulus,ductileHDPEal lowsthecompositehavingagoodbiocompatibilityandad equatemechanicalproperties.Unliketheconventionalim plantmaterialssuchasmetalsandceramics,HDPE HAcompositesmatchthemechanicalproperties(ie,stiffnessandstrength)ofcorticalbone.Thereby,itavoidsthe…     

Preparation and Mechanical Properties of HIPS Composites Containing PS-grafted-hydroxyapatite Particles

The surfaces of the micron- sized HA particles were modified by in situ copolymerization of vinyl triethoxyl silane （VIES） and styrene （ St ）. Then, the modified HA particles were compounded with HIPS. The results showed that the polystyrene （PS） macromolecules were grafted on the surfaces of HA particles during in situ copolymerization of VIES and St. Thereby, PS chains grafted on the HA surface enhance the compatibility between HA and HIPS, improve the dispersion of HA particles in HIPS matrix, and enhance the interfacial adhesion between HA and matrix. The stiffness, tensile strength and notch impact strength of HIPS/HA composites are improved at the same time. And there is a critical coating thickness of PS to the HA surface for the optimum mechani- cal properties of HIPS/HA composites.     

Enhanced Interfacial Adhesion in HDPE/HA Composites by Surface Modification of HA Particles via in situ Polymerization and Copolymerization

Hydroxyapatite （ HA ）- reinforced high density polyethylene （HDPE） was developed as a bone replacement material,In order to enhaace the interfacial bonding between HA and polyethylene and improve the mechanical properties of HDPE/ HA composites, the surface of the micron-sized HA particles was modified by in situ polymerization of butyl acrylate （ BA ） and in situ copolymerization of vinyl triethoxyl silane （ VTES ） and BA , then the modifwd HA particles were compounded with HDPE. The effects of the surface modification of HA on morphology and mechanical properties of HDPE/ HA composites were investigated. The experimental results show that the presence of HA particles does tuft inhibit the polymerization of BA . The poly（ butyl acrylate） （ PBA ） segments on the HA surface enhance the compatibility between HA and HDPE, improve the dispersion of HA particles in HDPE matrix, and enhance the interfacial adhesion between HA and matrix. Surface modifieations , especially by in situ copolymerization of VTES and BA, significantly increase notch impact strengths and marginal stiffness and tensile strengths of HDPE/HA composites. And it is found that there is a critical thickness of PBA coating on HA panicles for optimum mechanical properties of HDPE / HA composites.     

Preparation and Mechanical Properties of HIPS Composites Containing PS-grafted-hydroxyapatite Particles

1Introduction Hydroxyapatiteisawell knownbioceramicthathas gainedmuchattentionfrombiologistsandbiomaterial scientists[1].Duetoitsreasonablemechanicalbehavior underlow loadconditionsandexcellentbiocompatibility,combinedwithslowreplacementbythehostboneafter…     

Hydroxyapatite/alumina nanocrystalline composite powders synthesized by sol-gel process for biomedical applications

Hydroxyapatite/alumina nanocrystalline composite powders needed for various biomedical applications were successfully synthe- sized by sol-gel process. Structural and morphological investigations of the prepared composite powders were performed using X-ray dif- fractometer （XRD）, scanning electron microscopy （SEM）, X＇Pert HighScore software, and Clemex Vision image analysis software. The re- suits show that the crystallite size of the obtained composite powders is in the range of 25 to 90 nm. SEM evaluation shows that the obtained composite powders have a porous structure, which is very useful for biomedical applications. The spherical nanoparticles in the range of 60 to 800 nm are embedded in the agglomerated clusters of the prepared composite powders.     

The Effects of Dense/Nanometer Hydroxyapatite on Proliferation and Osteogenetic Differentiation of Periodontal Ligament Cells

The objective of this study is to investigate possible effects of nanometer powder of hydroxyapatite on proliferation of periodontal ligament cells. With sol-gel method, the nanometer hydroxyapatite powder were fabricated. The primary periodontal ligcament cells were caltured on dense particle hydroxyapatite and nanometer particle hydroxyapatite. The effects on proliferation of periodontal ligament cell were examined in vitro with MTT （ methyl thiazolil tetracolium） test. The intercellalar effects were observed with scanning electron microscopy and energy dispersive X-ray analyzer. In addition, the influence of two materials on osteogenetic differentiation was determined with measurement of ALP （ alkaline phosphatase ） activity. It is concluded that nanometer hydroxyapatite can promote proliferation and osteogenetic differeraiation of periodontal ligament cells and it may become absorbable agent in osseous restoration.