纳米羟基磷灰石及其复合材料技术进展

介绍了纳米羟基磷灰石制备和掺杂技术,以及纳米羟基磷灰石复合材料,包括它们在组织工程支架材料、缓控释药物载体、靶向药物传递及环境功能材料等方面的制备技术和应用,显示纳米羟基磷灰石及其复合材料在生物医学领域将会有良好发展前景。     

纳米羟基磷灰石制备方法的研究进展

介绍了目前纳米羟基磷灰石的制备方法,重点阐述了化学沉淀法制备纳米羟基磷灰石的研究情况,并对纳米羟基磷灰石整个行业的发展做出了展望。     

纳米羟基磷灰石的制备方法研究进展

介绍了羟基磷灰石的应用和纳米羟基磷灰石的制备方法。总结了不同制备方法的优缺点,指出了寻找新的表面活性剂可以合成出性能更好的纳米羟基磷灰石。     

纳米羟基磷灰石的制备、性能及在牙膏中的应用

介绍了纳米羟基磷灰石的制备方法，纳米羟基磷灰石在牙齿再矿化、牙齿脱敏和牙齿美白方面的性能及纳米羟基磷灰石在牙膏中的应用。     

纳米羟基磷灰石粉体的制备工艺

简要介绍了羟基磷灰石的结晶结构和其理化性质,综合论述了纳米羟基磷灰石的制备工艺及其原理。同时,对常用制备方法进行了比较,指出了目前纳米羟基磷灰石粉体制备存在的问题及今后的发展方向。     

模板法在纳米羟基磷灰石制备中的应用进展

由于模板法可以有效地设计和调控纳米材料的形貌、结构、尺寸等,赋予纳米材料独特的性能,近年来,在介孔纳米羟基磷灰石的制备研究中,引起了学者们的广泛关注。简述了软模板法和硬模板法合成纳米羟基磷灰石的机理,重点综述了模板法在制备纳米羟基磷灰石中常用的模板剂类型,并总结了其优缺点,最后对模板法合成纳米羟基磷灰石进行了展望。     

模拟体液法制备纳米级羟基磷灰石

以制备羟基磷灰石粉体的其中一种反应体系为研究对象,用模拟体液法制备纳米羟基磷灰石粉体。在此实验过程中,研究了反应温度、反应浓度和反应时间对羟基磷灰石粉体合成的影响。结果发现,制备纳米级羟基磷灰石的最佳工艺条件为:反应温度为60℃,浓度为15SBF,反应时间为10h。在此工艺条件下,制备的羟基磷灰石粉体的微观形貌为球形颗粒,平均颗粒直径为30nm。     

含锶纳米羟基磷灰石的制备及性能研究

采用化学沉淀法制备了纳米掺锶羟基磷灰石（Sr-CaHAP）,通过XRD、FT-IR、TEM等手段,对纳米掺锶羟基磷灰石进行了结构分析。以牛血清白蛋白（BSA）为吸附目标,研究了纳米掺锶羟基磷灰石的吸附性能。结果表明,实验制备的纳米掺锶羟基磷灰石分散性好,是具有一定粒径的纳米针状晶体。在吸附时间为1 h、反应温度为45 ℃、pH为7时,掺锶羟基磷灰石对牛血清白蛋白的吸附量最大;且随着牛血清白蛋白浓度的增加,对牛血清白蛋白的吸附量也随之增加。相比较,掺锶羟基磷灰石对牛血清白蛋白的吸附量较羟基磷灰石大。     

功能化纳米羟基磷灰石改性聚乳酸复合材料的研究

采用硬脂酸对纳米羟基磷灰石进行表面改性,通过溶液共混和熔融挤出法制备纳米羟基磷灰石/聚乳酸复合材料。研究发现,改性后纳米羟基磷灰石在复合材料中的分散效果明显改善,同时与未改性的纳米羟基磷灰石/聚乳酸复合材料相比,改性后复合材料的一些力学性能有所提高。     

功能化纳米羟基磷灰石改性聚乳酸复合材料的研究

采用硬脂酸对纳米羟基磷灰石进行表面改性,通过溶液共混和熔融挤出法制备纳米羟基磷灰石/聚乳酸复合材料。研究发现,改性后纳米羟基磷灰石在复合材料中的分散效果明显改善,同时与未改性的纳米羟基磷灰石/聚乳酸复合材料相比,改性后复合材料的一些力学性能有所提高。     

Kinetics of Hydroxyapatite Formation at Low Temperature

The influence of temperature on the kinetics of formation of calcium-deficient hydroxyapatite by an acid-base reaction has been determined. Calcium-deficient hydroxyapatite is compositionally similar to bone apatite. Reactants used in this study were tetracalcium phosphate, a calcium phosphate more basic than hydroxyapatite, and dicalcium phosphate, which is more acidic than hydroxyapatite. The kinetics of hydroxyapatite formation are initially controlled by the surface areas of the reactants; however, eventually the rate of hydroxyapatite formation becomes diffusionally controlled. The origin of diffusion control appears to be associated with the epitaxial formation of hydroxyapatite on the surface of the dicalcium phosphate reactant. The microstructure of hydroxyapatite formed at 5°, 15°, and 25°C were generally similar and are characterized by the formation of a porous acicular product which covers the surfaces of the reactants. The microstructure of the hydroxyapatite formed at 38°C was distinct from this and exhibited a pseudomorphic relationship with the dicalcium phosphate reactant. Seeding with hydroxyapatite accelerated the initial reaction but did not appear to have major long-term effects on the fractional degree of reaction or on microstructural development. Reaction was also accelerated in a neutral salt solution of high ionic strength.     

PA1010/羟基磷灰石复合材料的制备与性能

利用熔融共混法制备了聚酰胺1010(PA1010)/羟基磷灰石(HA)复合材料,采用傅立叶变换红外光谱、热重分析仪和差示扫描量热仪测试了PA1010/HA复合材料的结构特征和热稳定性,利用电子万能试验机测试了PA1010/HA复合材料的力学性能。结果表明:复合材料中PA1010与HA之间通过氢键作用结合,而氢键作用的主要发生位置在PA1010酰胺键的氨基与HA的羟基之间;PA1010/HA复合材料具有良好的热稳定性,HA的加入对PA1010/HA复合材料的熔点基本没有影响,随着HA含量的增加,其熔融焓和结晶焓都降低。HA的加入,增强了PA1010/HA复合材料的拉伸性能和弯曲性能,与纯PA1010相比,分别提高了33.4%,98.3%。     

羟基磷灰石生物陶瓷的研究状况及发展趋势

综合论述了羟基磷灰石生物陶瓷的研究状况、分类、特性以及主要合成方法。同时，综合探讨了羟基磷灰石生物陶瓷临床应用中存在的问题及目前解决问题的途径和未来的发展趋势。     

羟基磷灰石及其复合多孔支架材料的研究概况

本文综合论述了羟基磷灰石及其多孔材料的性质,以及Ca—P“溶解－沉淀”机制对羟基磷灰石的骨传导特性的解释,概括了应用于医学骨组织领域的多孔高生物活性羟基磷灰石材料所要求具备的性能要求,并分析了羟基磷灰石复合材料的优点以及研究进展。     

Microstructure and <Emphasis Type="Italic">in vitro</Emphasis> Bioactivity of Silicon-Substituted Hydroxyapatite

Silicon-substituted hydroxyapatite has shown superior biological performance compared to its stoichiometric counterpart both in vitro and in vivo. In the present study, single-phase silicon-substituted hydroxyapatite was successfully synthesized by the precipitation method. Chemical composition, crystalline phase, microstructure, and morphology of the materials were characterized by XRF, XRD, FT-IR, solid-state NMR and SEM. The results showed that hydroxyapatite kept its original structure with silicon up to a level of 0.9 wt%. The precipitation method was proved to be an efficient way to synthesize single-phase silicon-substituted hydroxyapatite. Solid-state NMR combined with other techniques gave direct evidence for the isomorphous substitution of PO₄ ^3- by SiO₄ ^4- in the hydroxyapatite structure. Silicon-substituted hydroxyapatite showed better bioactivity than stoichiometric hydroxyapatite in the in vitro bioactivity experiment. The higher the silicon content in the hydroxyapatite structure, the better the in vitro bioactivity. The enhanced bioactivity of silicon-substituted hydroxyapatite over pure hydroxyapatite has been attributed to the effect of silicate ions in accelerating dissolution.     

金属基生物活性羟基磷灰石涂层材料的研究进展

羟基磷灰石(HA)是人体和动物的骨骼和牙齿的主要无机成分,人工合成的羟基磷灰石具有良好的生物相容性和生物活性,但质脆;医用金属材料具有较好的强度、韧性和优良的加工性能,但是生物相容性差。金属基生物活性HA涂层材料兼备金属材料优良的力学性能和生物陶瓷材料的生物相容性,成为近年来发展最为迅速的一种生物材料。本文简要评述了国内外金属基HA涂层材料的研究进展状况,主要介绍了制备金属基HA涂层材料的各种物理化学方法,提出了一些存在的问题和解决方法,展望了制备HA复合涂层的发展前景。     

再生丝素蛋白/羟基磷灰石多孔复合材料的制备

再生丝素蛋白具有良好的生物相容性,羟基磷灰石同时还具有成骨诱导性。通过将再生丝素蛋白制备形成丝素蛋白多孔材料,并在37℃下将其浸渍于模拟体液中可以制备再生丝素蛋白/羟基磷灰石多孔复合材料。扫描电镜研究发现在再生丝素蛋白多孔材料的孔隙中羟基磷灰石由针状晶体聚集而成,红外光谱和XRD等表征表明复合材料中羟基磷灰石以羰基取代的羟基磷灰石存在。制备的再生丝素蛋白/羟基磷灰石多孔材料有望作为骨组织修复材料使用。     

乙二胺四乙酸二钠对镍钛合金表面电沉积羟基磷灰石涂层的影响

先用10mol/L的NaOH溶液处理镍钛片,随后采用电沉积法制备羟基磷灰石涂层。电沉积工艺参数为:硝酸钙0.042mol/L,磷酸二氢铵0.025mol/L,EDTA-2Na1.5×10-4mol/L,温度65℃,pH4.5,电流密度1mA/cm2,时间1h。采用扫描电镜、红外光谱仪和能谱仪对所得涂层进行表征。NaOH溶液处理有利于羟基磷灰石的生长。溶液中EDTA-2Na的存在不影响羟基磷灰石的生成,只是促使羟基磷灰石末端聚拢,使羟基磷灰石之间的空隙扩大,并减少涂层的CO3-2含量,增加OH-,有效减少了涂层的镍含量。     

Nanocomposite biomaterials based on hydroxyapatite xerogel

A hydroxyapatite xerogel with high adsorption-structural characteristics and nanometer-sized crystals has been synthesized using dehydration of a hydroxyapatite gel in air at temperatures of 20–40°C with dehydrating agents, cryogenic treatment (−18 and −196°C), lyophilic drying, and vacuum conductive-sorption drying. The following nanocomposite biomaterials based on the hydroxyapatite xerogel have been prepared and investigated: hardening hydroxyapatite cements, elastic “hydroxyapatite-fiber carrier (cellulose, carbon)” composites, and hydroxyapatite coatings on titanium substrates. It has been established that the hardening calcium phosphate cements based on a 4- to 17-wt % hydroxyapatite gel and a hydroxyapatite powder are characterized by a hardening time in the interval from 1 min to 1 h and by a static strength up to 2.7 MPa. The hydroxyapatite content in the elastic composites varies from 4 to 540 mg/g depending on the type of fiber carriers and on the preparation conditions. In vitro and in vivo preclinical tests performed on rats have demonstrated that titanium implants with a biocoating based on the hydroxyapatite cement possess a high biocompatibility and a toxicological safety.     

New hydroxyapatite–hydrotalcite composites II. microwave irradiation effect on structure and texture

Acid-basic materials are often used to catalyse organic reactions. Hydroxyapatite is acidic and hydrotalcite presents basic properties. The association of both compounds in a single material should present a rather unique catalytic behavior. Three preparations of hydroxyapatite impregnated with hydrotalcite are presented. The effect of microwave irradiation, at different preparation levels, is discussed. A homogeneous distribution of hydrotalcite on hydroxyapatite surface is obtained when hydrotalcite is precipitated over a previously microwave irradiated hydroxyapatite. Instead, if the hydrotalcite mixture is incorporated to the hydroxyapatite precursor gel and the resulting mixture microwave irradiated, hydrotalcite is preferentially deposited in the hydroxyapatite interparticle spaces. When both hydroxyapatite and hydrotalcite solutions are irradiated, mixed and irradiated again, the composite behaves as the addition of the two components.