硅替代纳米羟基磷灰石的研究进展

硅元素掺杂羟基磷灰石可有效提高移植骨组织生物活性和生物相容性,在骨修复材料领域有着广泛的研究。概述了硅元素在骨修复材料中的作用,硅替代纳米羟基磷灰石粉体的制备、表征方法、替代机理及硅替代羟基磷灰石生物陶瓷在体内、体外实验中的最新研究成果,同时综述了硅替代羟基磷灰石目前存在的一些问题和其在骨修复材料方面的发展前景。     

含硅羟基磷灰石粉体的合成及其与蛋白质的相互作用研究

将硅掺入羟基磷灰石(HA)晶格中能有效地提高HA的生物相容性.采用湿法合成了含硅羟基磷灰石微粉(Si-HA),用X射线荧光光谱(XRF)、X射线衍射(XRD)、红外光谱(FTIR)、扫描电镜(TEM)和荧光光谱等对Si-HA的晶相、结构、化学组成、形貌及其与牛血清白蛋白(BSA)的相互作用进行了表征和分析.结果表明:Si元素溶入磷灰石晶格中,使HA晶胞参数和结构发生变化,随着Si含量的增加,HA中-OH和PO3-4的吸收峰呈减弱趋势,表明SiO4-4可能部分取代了PO3-4.Si-HA与BSA作用后的PO3-4吸收峰发生变化,在Si-HA图谱中出现了蛋白质的酰胺Ⅰ带和酰胺Ⅱ带吸收峰,随着Si-HA与BSA作用时间由2h～3d的变化,BSA溶液酰胺I带位置出现蓝移,半峰宽减小且峰型变得尖锐,酰胺II带则向低频区移动.Si-HA与BSA作用3d后,开始在1139处出现PO3-4的吸收峰.荧光光谱显示:加入相同质量的HA和Si-HA后蛋白质内源荧光强度较纯BSA溶液下降,随着Si-HA中Si质量分数的增加BSA荧光强度下降幅度增大,发射峰也出现红移,且Si-HA与BSA作用较纯HA与BSA的作用强,说明Si-HA使蛋白质二级结构发生改变,Si-HA中的Ca、PO3-4、SiO4-4与BSA之间发生了相互溶解、吸附和键合等作用,证明了Si-HA与生命物质蛋白质之间具有较高的反应性能,对Si-HA的生物活性及其与BSA相互作用的机理进行了详尽的阐述.     

制备生物活性羟基磷灰石陶瓷粉末的新工艺

为开发制备含CO32-的羟基磷灰石(HA)新工艺,以Ca(OH)2-H3PO4为原料,依据中和法原理,用CaCO3代替部分Ca(OH)2,采用不同于常规的反应温度和加料操作制备HA.通过控制反应体系终点pH值、反应时间和反应温度制得含CO32-的羟基磷灰石,并用XRD和IR技术分析了生成物的组成和结构.研究结果表明:采用本文工艺生成的沉淀物不经陈化,易于过滤分离;制备较佳工艺条件为:反应体系终点pH值控制在微酸性条件(pH=6),反应温度≥75℃,沉淀反应时间约3 h.     

碳羟基磷灰石的吸附性能研究

综述了目前关于碳羟基磷灰石(CHAP)吸附性能的研究,主要介绍了CHAP的类型、与羟基磷灰石(HAP)相比的结构变化和对吸附性能的影响、对重金属离子的吸附影响因素和不同碳含量对吸附性能的影响,最后探讨了CHAP的吸附机理.     

人血清浸泡纳米羟基磷灰石及其聚酰胺复合材料的表面生物活性研究

对n-HA及n-HA／PA66复合材料在人血清中的浸泡行为进行了研究。通过ICP、FT-IR、XRD、SEM等检测手段,分析了n-HA及n-HA／PA66复合材料浸泡前后表面化学组成、结晶结构及表面形貌等的变化。结果表明,n-HA及n-HA／PA66复合材料表面均能吸附蛋白质,并在材料表面生成了与骨磷灰石相似的类骨磷灰石层。这对材料植入体内与骨组织形成骨性键合有着重要意义。同时,也说明了n-HA／PA66复合材料具有优异的生物活性。     

羟基磷灰石表面吸附性能的研究综述

羟基磷灰石(HA)吸附能力受酸碱度、其它离子浓度等外界因素的影响,对HA表面改性处理能在一定程度上改变HA表面电性结构,从而改善吸附性能.动力学上多因素作用影响HA吸附速度或改变具体的吸附行为.通过总结HA对无机物、金属及有机物的作用条件、反应过程及吸附机理发现:人们还没有找到一个普遍的理论模型来解释HA与其它材料发生吸附作用的过程,目前对HA表面吸附性能的研究还停留在具体零碎材料的相互作用上.在HA表面嫁接有用的作用基团或物质,通过改变HA表面部分结构以改善吸附性能成为目前和今后一段时间内HA吸附性能研究的重点之一.     

湿法制备羟基磷灰石生物活性陶瓷粉末的热力学分析

本文对制备羟基磷灰石的Ｃａ（ＮＯ３）２－（ＮＨ４）２ＨＰＯ４－ＮＨ４ＯＨ－Ｈ２ＯＬ体系进行热力学分析。计算求得ＨＡ沉淀最宜ｐＨ条件为１０．６－１２．４，热力学计算与实验结果和文献报告数据结果一致。     

羟基磷灰石纳米棒的合成及其体外生物活性研究

在没有任何表面活性剂存在的情况下，利用水热法合成了尺寸分布均匀的羟基磷灰石（HAp）纳米棒，其长度和直径分别为0．5～1．51am和45～60nm。通过模拟体液（SBF）浸泡实验，研究了其体外生物活性。结果显示，浸泡10d后的羟基磷灰石纳米棒直径变为60～140nm，表面有新的羟基磷灰石层的形成，表明了该羟基磷灰石纳米棒具有良好的生物活性．     

电化学制备羟基磷灰石涂层的生物活性研究

应用电化学沉积方法在钛金属表面制得致密均匀的羟基磷灰石涂层;使用MG63人成骨肉瘤细胞的培养评价涂层的生物活性.结果表明电化学沉积方法制得的羟基磷灰石涂层具有优良的生物相容性,涂层的晶粒尺寸及涂层的微观形貌对涂层的生物性能有较大影响.     

水热制备锌、硅、镁、铁等元素掺杂羟基磷灰石及其表征

微量元素掺杂是赋予羟基磷灰石材料更多生物学功能的一条有效途径, 但不同元素的掺杂行为尚待进一步揭示。本研究使用并行水热合成方式, 制备分别含有锌、硅、镁、铁、锰、铜、锶、硒、钴的9种羟基磷灰石粒子, 并对其物理化学特性进行研究。结果表明, 元素掺杂显著改变了羟基磷灰石粒子的形貌和晶体生长方向, 但不改变其物相组成和官能团。晶体的(211)和(112)晶面衍射峰的强度均降低, 结晶度下降。元素实际掺杂效率分析结果显示锰>锌>镁>铁(三价)>锶>钴>铜>硒>硅, 与元素的离子半径大小相关。锰、锌、镁三种元素掺杂量较高, 因其离子半径与其替代的钙离子接近。铜元素掺杂效率较低是由于其在合成溶液中与氨产生络合作用, 硅元素和硒元素则因几何结构和电荷(SiO₃^2-、SeO₃^2-/PO₄^3-)差异导致掺杂率低。本研究揭示了掺杂行为与离子特性之间的联系, 为功能化羟基磷灰石的设计和开发提供有益的参考基础。     

汽巴蓝功能微球对人血清白蛋白的吸附性能研究

通过分散共聚制得了聚苯乙烯接枝聚醋酸乙烯酯(PSt-g-PVAc)微球,粒径控制在500～700nm之间.在碱性条件下将PSt-g-PVAc微球表面的PVAc链醇解为聚乙烯醇(PVA),得到了PSt-g-PVA微球,提高了其在水中的分散稳定性.使汽巴蓝(CB)与PSt-g-PVA表面的羟基进行亲核反应,制得了CB作为配体的新型吸附剂汽巴蓝功能微球(CB微球),元素分析测得CB微球表面的CB最大含量为139.22μmol/g,探讨了其在不同人血清白蛋白(HSA)浓度、pH值和吸附时间下对HSA的吸附性能.当HSA浓度为1.0mg/mL、pH为5.14时,CB微球对HSA的最大吸附量为40.9mg/g,并分析了CB微球与HSA的相互作用机理.由NaSCN进行解吸试验,发现可将吸附在CB微球上的HSA解吸92.11%以上,且CB微球的重复使用性能良好.     

Competitive adsorption of fibronectin and albumin on hydroxyapatite nanocrystals

Abstract

Competitive adsorption of two-component solutions containing fibronectin (Fn) and albumin (Ab) on hydroxyapatite (HAp) nanocrystals was analyzed in situ using the quartz crystal microbalance with dissipation (QCM-D) technique. Adsorption of the one-component protein (Fn or Ab) and the two-component proteins adjusted to different molar ratios of Fn to Ab at a fixed Fn concentration was investigated. The frequency shift (Δf; Hz) and the dissipation energy shift (ΔD) were measured with the QCM-D technique, and the viscoelastic changes of adlayers were evaluated by the saturated ΔD/Δf value and the Voigt-based viscoelastic model. For the adsorption of the one-component protein, the Fn adlayer showed a larger mass and higher viscoelasticity than the Ab adlayer, indicating the higher affinity of Fn on HAp. For the adsorption of the two-component proteins, the viscoelastic properties of the adlayers became elastic with increase in Ab concentration, whereas the adsorption mass was similar to that of Fn in the one-component solution regardless of the Ab concentration. The specific binding mass of the Ab antibody to the adlayers increased with increase in Ab concentration, whereas that of the Fn antibody decreased. Therefore, Fn preferentially adsorbs on HAp and Ab subsequently interacts with the adlayers, indicating that the interfacial viscoelasticity of the adlayers was dominated by the interaction between Fn and Ab.     

Competitive adsorption of fibronectin and albumin on hydroxyapatite nanocrystals

Competitive adsorption of two-component solutions containing fibronectin (Fn) and albumin (Ab) on hydroxyapatite (HAp) nanocrystals was analyzed in situ using the quartz crystal microbalance with dissipation (QCM-D) technique. Adsorption of the one-component protein (Fn or Ab) and the two-component proteins adjusted to different molar ratios of Fn to Ab at a fixed Fn concentration was investigated. The frequency shift (Δf; Hz) and the dissipation energy shift (ΔD) were measured with the QCM-D technique, and the viscoelastic changes of adlayers were evaluated by the saturated ΔD/Δf value and the Voigt-based viscoelastic model. For the adsorption of the one-component protein, the Fn adlayer showed a larger mass and higher viscoelasticity than the Ab adlayer, indicating the higher affinity of Fn on HAp. For the adsorption of the two-component proteins, the viscoelastic properties of the adlayers became elastic with increase in Ab concentration, whereas the adsorption mass was similar to that of Fn in the one-component solution regardless of the Ab concentration. The specific binding mass of the Ab antibody to the adlayers increased with increase in Ab concentration, whereas that of the Fn antibody decreased. Therefore, Fn preferentially adsorbs on HAp and Ab subsequently interacts with the adlayers, indicating that the interfacial viscoelasticity of the adlayers was dominated by the interaction between Fn and Ab.     

Selective adsorption of acidic protein of bovine serum albumin onto sheet-like calcium hydroxyapatite particles produced by microreactor

The protein adsorption behavior onto sheet-like calcium hydroxyapatite Ca₁₀(PO₄)₆(OH)₂ (Hap) particles produced by microreactor was examined by using typical acidic bovine serum albumin (BSA) and basic lysozyme (LSZ). Since the sheet-like Hap particles were highly growth through b- (or a-) and c-axes, the particles had larger fraction of bc (or ac) crystal face. The saturated amounts of adsorbed BSA ($n_s^{\text{BSA}}$) for the sheet-like Hap nanoparticles were increased with increase in the particle size; i.e., $n_s^{\text{BSA}}$ showed a good linear relationship with the total surface area of bc and ac faces of each particle. This result strongly suggested that the sheet-like Hap particles progressed in b- and c-axes with large fraction of C sites on bc and ac particle faces and exhibit a high selective adsorption of BSA. On the contrary, very few LSZ molecules adsorbed onto sheet-like Hap particles. Hence the present study developed that the amounts of adsorbed protein, especially for BSA, can be controlled optimally by altering the size of sheet-like Hap particles. It was also found that the sheet-like Hap particles can be applied to separate completely BSA molecules from BSA–LSZ mixed solution.     

N-组氨酸壳聚糖/聚乳酸支架吸附牛血清白蛋白研究?

采用二次相分离制备7种 N-组氨酸壳聚糖/聚乳酸(NHCS/PLLA)支架,考察其在模拟体液中对牛血清白蛋白(BSA)的吸附性能,并研究其吸附等温式、吸附动力学和热力学行为等.结果表明,在37．0℃、BSA 的初始浓度为2．5 mg/mL 时,50 kD-NHCS-3与PLLA质量比为5/5制得的 NPs3支架对BSA 的吸附容量最大,达928．53 mg/g;吸附遵循Langmuir吸附等温式和准一级动力学方程,可为分离纯化BSA提供借鉴.     

Molecular dynamics simulations of the adsorption of amino acids on the hydroxyapatite {100}-water interface

The understanding of interfaces and interaction of organic molecules and inorganic materials are the important issues in biomineralization. Experimentally, it has been found that amino acids (AA) can regulate the morphology of hydroxyapatite (HAP) crystals significantly. In this study, molecular dynamics simulation is employed to investigate the detailed adsorption behavior of polar, ionic, and hydrophobic AA on the {100} face of HAP at the atomic level. The results indicate that various AA are adsorbed on the HAP crystal surface mainly by amino and carboxylate groups at the specific sites. Multiple interaction points are found for polar and ionic AA. The adsorbed AA molecules occupy the Ca and P sites of the HAP surfaces which may inhibit and regulate the HAP growth. The adsorbed amino acid layer can also change the interfacial hydration layer and influence the transportation of ions in and out of HAP, which may be another strategy of biological control in biomineralization.     

含钾羟基磷灰石粉体的制备及其吸附性能研究?

采用化学沉淀法制备出 Ca3(PO4)2粉体,经过高温煅烧得到α-Ca3(PO4)2粉体.将粉体投入到KOH 溶液中,在120℃温度下水化不同时间,制备出含钾羟基磷灰石粉体,利用 X 射线衍射,透射电子显微镜进行分析表征.再将含钾羟基磷灰石粉体投入到NaF溶液中,研究粉体对 F－的吸附性.实验结果表明,含钾羟基磷灰石粉体对氟离子的吸附采用Lagerg-ren拟二级反应动力学方程拟合效果较好,吸附速率较快,吸附机制主要是通过离子交换作用.将吸附过程通过 Langmuir/Freundlich 吸附等温模型拟合,采用Langmuir模型拟合效果较好,静态吸附饱和量为31．55 mg/g.     

TiO2纳米管阵列膜对牛血清白蛋白的吸附与脱附

采用电化学阳极氧化法以含氟的乙二醇溶液为电解液阳极氧化纯钛制备出排列规则的高长径比TiO2纳米管阵列膜,并用扫描电镜(SEM)、比表面积仪表征了TiO2纳米管阵列膜的形貌和比表面积。结果表明,所制得的TiO2纳米管阵列的管径约180nm,管长可达230μm,比表面积约59.8m2/g。以牛血清白蛋白(BSA)为药物蛋白分子的模型,并研究了TiO2纳米管阵列膜对BSA的吸附和脱附行为,考察了溶液pH值、BSA初始浓度和溶液离子强度对BSA吸附的影响与吸附态的BSA在不同pH值的PBS溶液中的释放行为。结果表明,BSA分子在其等电点(pH值=4.8)附近较容易吸附到TiO2纳米管上,吸附量随着BSA初始浓度的增加而增加,较高的离子强度会降低BSA的吸附,碱性条件下吸附态的BSA容易从TiO2纳米管上脱附,并由于纳米管的扩散限制效益呈现一定程度的缓释。