纳米羟基磷灰石/聚乳酸复合材料力学性能

将纳米羟基磷灰石(n-HA)和聚乳酸(PUA)在溶剂中混合,干燥后再采用热压成型工艺制备n-HA/PLLA复合材料.制备过程中n-HA采用F-127和PEG改性处理.拉伸实验发现:n-HA加入PLLA基体中,能提高PLLA的塑性;PEG改性n-HA与PLLA复合力学性能较好,PEG可以改善HA的分散性.扫描电镜图片显示:与PLLA比较,PEG改性n-HA/PLLA复合材料的断裂为韧性断裂,PLLA的断裂接近脆性断裂.     

β-磷酸三钙/聚L-乳酸复合支架材料制备过程中的表面改性研究

对β TCP粉末表面改性剂进行了筛选,并对棕榈酸的改性效果进行了优化研究。通过润湿角测量仪、扫描电镜(SEM)和 X光电子能谱(XPS)分别对改性前后β TCP 的水性接触角、颗粒形貌以及表面—OH基团进行了表征,同时研究了改性β TCP/聚乳酸(PLLA)复合材料的力学性能。结果表明:用 1%棕榈酸在20min超声分散搅拌处理后的β TCP 微粒具有良好的疏水性,且在 PLLA 基质中分散均匀;通过棕榈酸改性,改善了β TCP/PLLA复合材料界面粘结强度,提高了复合材料的力学性能。     

硬脂酸改性β-磷酸三钙及其复合材料机械性能研究

为了提高β-磷酸三钙(β-TCP)复合材料的机械性能,采用硬脂酸(C17H25COOH)对β-TCP表面进行改性处理,研究了β-TCP与C17H25COOH的界面作用机理.利用透射电镜、傅里叶红外光谱、热重分析等技术分别对改性前后β-TCP的颗粒形貌、组分和表面—OH基团进行了表征,研究了改性β-TCP/聚左旋乳酸(PLLA)复合材料的机械性能,并利用扫描电镜观察了复合材料断面形貌.研究表明:硬脂酸包覆在β-TCP表面,改性后β-TCP粉末具有一定的疏水性,硬脂酸的H+可以与β-TCP中的PO43-的一个O发生质子化反应形成—OH.改性β-TCP/PLLA复合材料的机械性能相比改性前有明显提高,改性后的β-TCP微粒在PLLA中分散均匀,两者结合紧密.     

HA改性短切碳纤维/PMMA生物复合材料力学性能的研究

采用原位合成与溶液共混的方法,制备了纳米羟基磷灰石(HA)-短切碳纤维（C_f）/聚甲基丙烯酸甲酯(PMMA)生物复合材料, 研究了HA对HA-C_f/PMMA复合材料的力学性能和微观结构的影响. 采用万能材料试验机测试了HA-C_f/PMMA复合材料的力学性能,用X射线衍射仪（XRD）、透射电镜（TEM）、场发射扫描电子显微镜（FESEM）和红外吸收光谱仪(FT-IR)分析测试手段对材料的组成结构及断面的微观形貌等进行了测试和表征. 结果表明,采用卵磷脂改性后的HA纳米片与PMMA基体的界面结合性能得到了有效改善,显著提高了复合材料的力学性能;随着HA含量的增加,HA-C_f/PMMA复合材料的弯曲强度、拉伸强度、压缩强度、弯曲模量和拉伸模量均呈先增大后减小的趋势. 当HA含量在8wt%时,复合材料的力学性能最佳.     

聚DL-丙交酯/羟基磷灰石(PDLLA/HA)复合材料:(Ⅳ)HA表面处理及PDLLA界面作用研究

采用3-甲基丙烯酸丙酯-三甲氧基硅烷(A-174)、聚丙烯酸(PAA)分别对羟基磷灰石(HA)表面进行改性处理,通过溶液共混、取向模压成型技术制备出直径为3.2 mm的聚DL-丙交酯(PDLLA)/HA复合棒材。上述方法由于增进了复合材料在界面的相互作用,从而引起复合材料玻璃化转变温度升高,力学性能也得到了明显的改善。      

羟基磷灰石/液晶复合材料仿生人工骨的制备及性能

通过优化的加工条件制备了羟基磷灰石/热致液晶高分子(HA/Vectra A950)复合材料仿生人工骨, 研究了HA含量对复合材料显微结构和力学性能的影响, 分析了HA与Vectra A950共混后的力学性能以及界面结合问题。研究结果表明: 当HA与Vectra A950的质量比小于10∶100时, 复合材料呈现明显的皮芯结构, 皮层液晶微纤高度取向, HA主要分散在芯部, 其模量和强度达到或超过天然骨的力学性能; 随着HA含量的增加, 皮芯结构逐步减弱并消失, 而缺陷显著增加。当HA与Vectra A950的质量比增加到20∶100, 复合材料的力学性能、尤其是韧性显著降低, 这可能是由于HA颗粒与液晶基体之间的结合较差导致的。为保证复合材料仿生人工骨的生物活性, HA的含量应与天然骨接近。因此, 需对HA和Vectra A950的界面进行改性以提高其结合性能。      

玻璃纤维表面纳米SiO_2改性对GF/PCBT复合材料力学性能的影响

为研究玻璃纤维(GF)表面纳米SiO2改性对GF增强树脂基复合材料力学性能的影响,利用真空辅助模压(VAMP)工艺制备了不同含量的纳米SiO2表面改性GF增强聚环状对苯二甲酸丁二醇酯(PCBT)复合材料。分析了GF表面改性对GF/PCBT复合材料力学性能的影响,研究了纤维表面改性对GF/PCBT复合材料抗湿热老化性能的影响规律。纤维拔出试验结果表明:经表面处理的GF/PCBT复合材料的界面剪切强度提高了1.16倍;采用含量为0.5wt%和2wt%(与树脂质量比)的纳米SiO2处理GF表面后,复合材料的三点弯曲强度分别提高1.5倍和1.67倍,弯曲模量分别提高1.03倍和1.17倍。SEM结果显示:当纳米SiO2用量为2wt%时,破坏后的纤维表面被树脂完全覆盖,树脂与纤维粘结良好。在湿热条件下,由于纳米SiO2颗粒的存在,水分子很难通过界面相扩散到改性后的材料内部,其抗湿热性能提高。     

磷酸单酯偶联剂改性羟基磷灰石/高密度聚乙烯复合人工骨材料的制备和性能

采用磷酸单酯偶联剂对羟基磷灰石( HA) 进行表面改性处理, 通过熔融共混复合等工艺制备了改性HA/ 高密度聚乙烯( HDPE) 复合人工骨材料。用IR、TGA 和燃烧实验对复合材料的结构和组成进行了表征, 并对复合材料的流变性能、热稳定性、力学性能进行了初步研究。结果表明,所制备的改性HA/ HDPE 复合材料比未改性HA/ HDPE 具有更好的流变性能和机械力学性能, 组成均一, 具有良好的热稳定性, 通过控制复合材料中改性HA 及HDPE 配比, 可制备出机械力学性能优良的复合人工骨材料, 在生物医学材料研究中具有重要意义。      

高HA含量的PEKK/HA复合材料的制备及其力学相容性

本研究合成了一种由高分子聚醚酮酮(PEKK)和羟基磷灰石(HA)组成的复合材料,其中部分HA被PEKK包裹,制得的PEKK/HA复合材料中HA的质量分数达到50%,与人体骨骼中HA的含量相近。该复合材料中HA在PEKK中分布均匀,无明显的相分离现象,模量为14.5GPa,硬度为0.5GPa,断裂屈服强度为167.65MPa,此三项力学性能均与人体骨骼的性能接近。     

改性纳米MgO/PLLA复合薄膜的制备及性能

为了改善左旋聚乳酸(PLLA)的降解性,采用溶液共混法将PLLA和MgO纳米颗粒(MgO-NPs)进行复合,制备了一种具有良好力学性能的骨修复复合材料.结果显示:改性MgO纳米颗粒(g-MgO-NPs)在PLLA基体中的分散效果及界面结合性比未改性的好.4%(质量比)g-MgO-NPs的添加量使薄膜的拉伸强度从10.6 MPa增大到30.1 MPa,断裂伸长率从71%减小为59%,并使薄膜降解后的pH值趋于稳定,基本接近生理盐水的pH值.由此表明:g-MgO-NPs在一定程度上能改善聚乳酸复合膜的降解性及其力学性能.     

羟基磷灰石（HA）生物复合材料的研究进展

综述了强韧化羟基磷灰石生物复合材料的类型,烧结制备和力学性能等方面的研究进展,并简单介绍了功能性活性ＨＡ生物复合材料。     

Hydroxyapatite (HA) bone scaffolds with controlled macrochannel pores

Hydroxyapatite (HA) macrochanneled porous scaffolds, with a controlled pore structure, were fabricated via a combination of the extrusion and lamination processes. The scaffold was architectured by aligning and laminating the extruded HA and carbon filaments. The macrochannel pores were formed by removing the carbon filaments after thermal treatments (binder removal and sintering). The porosity of the scaffolds was varied between 48 and 73% with a controlled pore size of ∼450 μm, by adjusting the fractions of HA and carbon filaments. As the porosity was increased from 48 to 73%, the compressive strength decreased from 11.5 to 3.2 MPa. However, the osteoblast-like cell responses on the scaffold, such as the proliferation rate and alkaline phosphatase (ALP) activity, were significantly enhanced as the porosity was increased.     

致密羟基磷灰石（HA）生物陶瓷烧结行为和力学性能

从生物相容性的角度考虑,羟基磷灰石是人体硬组织置换种植体最适合的陶瓷材料。但目前ＨＡ陶瓷很差的力学性能使得它不能在受载场合下应用,如人造牙齿或骨。所以力学性能高的致密羟基磷灰石陶瓷或径基磷灰石基生物材料是我们所期望获得的。本文简要介绍了国内外关于在磷灰石,生物陶瓷烧结行为和力学性能的研究进展。     

Immersion behavior of hydroxyapatite (HA) powders before and after sintering

The immersion behavior of two different hydroxyapatite (HA) powders before and after sintering was investigated by soaking them in simulated body fluid (SBF) for various periods. The results showed that the mechanism of formation of bone-like apatite on the two HA powders was different due to their different phase composition. Moreover, after being sintered at a proper elevated temperature, the bioactivity of HA powders was increased.     

钛表面接枝壳聚糖诱导羟基磷灰石涂层的形成

钛及其合金材料广泛应用于矫形外科植入器械等生物材料领域,在钛表面制备羟基磷灰石涂层可以明显提高其生物相容性及其成骨性能.采用仿生溶液生长法在钛表面及共价接枝壳聚糖的钛表面沉积羟基磷灰石涂层,结果表明,与没有接枝壳聚糖的钛相比,在钛表面接枝壳聚糖可以加速诱导羟基磷灰石涂层的形成,且形成的涂层致密均匀.     

Hyaluronic acid (HA)-based hydrogels for full-thickness wound repairing and skin regeneration

In this work, two kinds of hyaluronic acid (HA)-based hydrogels were fabricated: one is made from physical freezing-thawing of HA solution (HA1), and the other is from chemical cross-linking of HA and polysaccharide (HA2). They were applied to repair full-thickness skin defects with New Zealand rabbits as the test animals, using powder HA and cotton dress as the references. The wound starts to heal after wounds were disinfected with iodine followed by coating with HA2, HA1, HA and cotton dress (the control), respectively. They were recorded as 4 treatments (groups), HA2, HA1, HA and the control. The healing progress was followed and tested in the duration of 56 days, and the biological repairing mechanism was explored. From the wound area alteration, white blood cell (WBC) measurements and H&E staining, HA2 was the most promising treatment in promoting the wound healing with least serious scar formation. Immunochemistry analyses and real-time PCR tests of the bio-factors involved in the wound healing, vascular endothelial growth factor (VEGF), alpha-smooth muscle actin (α-SMA) and transforming growth factor beta-1 (TGF-β1), exhibited that HA2 enhanced VEGF and α-SMA secretion but reduced TGF-β1 expression at early stage, which alleviated the wound inflammation, improved the skin regeneration and relieved the scar formation.     

Effect of hydrophilic–hydrophobic balance on biocompatibility of poly(methyl methacrylate) (PMMA)–hydroxyapatite (HA) composites

The purpose of this study is to put in evidence the correlation between hydrophilic/hydrophobic balance and biocompatibility of PMMA–HA composites, in order to select the best composites for futures clinical applications. For this purpose, PMMA–HA cements with different compositions were prepared and static contact angle measurements, water absorption and gingival fibroblasts cell culture were performed and discussed.     

磁控溅射法在生物材料表面制备羟基磷灰石涂层的研究现状

主要以牙科种植体为例,介绍钛合金和羟基磷灰石的性能及在生物材料应用中的局限,并简述磁控溅射法的优越性.概述了国内外利用磁控溅射制备生物涂层的动向,得出梯度功能复合膜层制备发展的大趋势及磁控溅射法制备涂层的良好前景,以及在牙科种植体的应用.     

An investigation of the chemical synthesis and high-temperature sintering behaviour of calcium hydroxyapatite (HA) and tricalcium phosphate (TCP) bioceramics

The experimental conditions for the synthesis of sub-micrometre,spherical particles of calcium hydroxyapatite[Ca10(PO4)6(OH)2] (HA) andtricalcium phosphate [Ca3(PO4)2] (TCP) areinvestigated through chemical coprecipitation from the aqueous solutions ofcalcium nitrate and di-ammonium hydrogen phosphate salts. The precipitationprocess employed was also found to be suitable for the production ofsub-micrometre HA/TCP composite powders in situ. The synthesized pureHA and TCP powders were found to be stable even at 1300°C in air forprolonged heating times. Bioceramic sample characterization was achieved bypowder X-ray diffraction (XRD), scanning electron microscopy (SEM), energydispersive X-ray spectroscopy (EDX), and density and surface area measurements.Crystallographic analyses of HA powders were performed by the Rietveld method onthe powder XRD data.     

聚乳酸涂层改善网状羟基磷灰石陶瓷支架力学性能的研究

采用有机泡沫浸渍法制备出高孔隙率的三维网状羟基磷灰石(HA)生物陶瓷支架,并采用不同浓度的聚乳酸(PDLLA)溶液涂覆网状HA支架,以达到增强补韧网化陶瓷支架的目的.通过扫描电镜观察PDLLA涂覆网状HA陶瓷支架的显微结构和测试力学强度,研究了不同浓度PDLLA溶液涂覆对网状HA支架的涂层厚度、显微结构和力学性能的影响.实验结果表明:涂覆一定量的PDLLA涂层可以显著提高网状HA生物陶瓷支架的抗压强度,同时保持网状陶瓷支架的贯通性和孔隙率.