不同分散剂对纳米羟基磷灰石粒子团聚的影响

为了解决纳米羟基磷灰石团聚的问题，在纳米羟基磷灰石制备过程中，加入适量的乙醇、铈盐和聚乙二醇作为表面分散荆，研究其分散作用。试验结果表明：乙醇具有脱水作用，减少毛细管收缩作用，具有一定的分散作用，且不改变HA六方晶体形貌；铈盐的加入，使六方晶体结构进一步分化，粒子尺寸变小，有细化纳米HA晶粒的作用及分散作用，同时，在分散过程中，参与反应，形成Ce5（PO4）3（OH）；聚乙二醇对纳米羟基磷灰石形貌影响不大，但在表面形成簿膜，隔阻纳米粒子间的接触，具有减少硬团聚的作用。     

戊二醛交联纳米羟基磷灰石/胶原复合材料作用机理研究

为了改善纳米羟基磷灰石／胶原复合材料界面结合性能,采用戊二醛对复合材料进行交联处理,并对交联前后复合材料的溶胀度,结合能进行了分析,研究戊二醛交联对羟基磷灰石／胶原复合材料溶胀度的影响,探讨了戊二醛交联羟基磷灰石／胶原复合材料的可能机理．结果表明,复合材料的溶胀度随戊二醛的浓度增加而降低,当戊二醛的浓度大于0．25％时,复合材料的溶胀度没有明显的变化．戊二醛交联促使羟基磷灰石与胶原之间形成更多键,导致O1s,Ca2p,N1s,P2p和C1s的化学状态和结合能变化,增加了胶原纤维与羟基磷灰石之间的界面结合强度。     

Comparison of Compositions and Structural Characterizations of Synthetic Nano-hydroxyapatite and Mineral Phase from Porcine Femoral Bone

In the paper, nano-hydroxyapatite was synthesized by hydrothermal treatment. The erystal morphology and compositions of the synthetic HA were investigated using TEM,IR, XRD and XPS techniques and were compared with those of porcine femoral bone apatite. The results showed that the synthetic HA is nanometer rod crystal similar to the bone apatite, and the average crystal sizes calculated by Scherrer equation for the four samples (HA dried at 80℃, unburned bone apatite, HA calcined at 750℃ and bone apatite calcined at 750℃ )are 20.6, 21.7, 22.5 and 27.6nm ,respectively, Moreover, the essential compositions for the synthetic HA and bone apatite are almost the same.     

纳米羟基磷灰石/聚乙烯醇/海藻酸钠复合水凝胶的结构与性质研究

采用溶液共混法制备了纳米羟基磷灰石/聚乙烯醇/海藻酸钠三元复合水凝胶材料,测定了复合材料的含水率,采用燃烧实验、扫描电子显微镜、傅里叶红外光谱及X射线衍射对复合材料的结构进行了表征和分析,并研究了复合材料的吸水性.结果表明,制备的复合水凝胶材料组成均匀,各组分间存在相互作用,并且具有好的吸水和保水性能,该复合水凝胶材料可作为一种人工软骨生物材料.     

Blood compatibility of nano-hydroxyapatite dispersed using various agents

Nano-hydroxyapatite (nHAP),dispersed with three kinds of dispersants (heparin sodium,polyacrylic sodium and wa-ter),reacted with red blood cell,Bel-7402 tumor cell,to compare their dispersing efficiency against nHAP from one another. The blood compatibility of nHAP is also determined by blood solubil-ity experiment so that the capability of different dispersant dis-persing against nHAP of different concentration and the relation between nHAP and blood compatibility have been determined. The inhibiting function of Bel-7402 against tumor cells is deter-mined with the MTT staining method. The study result shows that heparin sodium has the best dispersing efficiency for nHAP with-out the phenomenon of hemolysis.     

Preparation and characterization of chitosan/nano-hydroxyapatite composite used as bone substitute materials

Chitosan/nano-hydroxyapatite composites with different weight ratios were prepared through a co-precipitation method using Ca（OH）2, H3PO4 and chitosan as starting materials. The properties of these composites were characterized by means of TEM, IR, XRD, TGA, burn-out tests and universal matertial testing machine. The results showed that the HA synthesized here was poorly crystalline carbonated nanometer crystals and dispersed uniformly in chitosan phase and there was no phase-separation between the two phases. The addition of n-HA resulted in a decrease of decomposing temperature of chitosan. Because of the interactions between chitosan and n-HA, the mechanical properties of these composites were improved, and the maximum value of the compressive strength was measured to be about 120MPa corresponding to the chitosan/n-HA composite with a weight ratio of 30/70.     

羟基磷灰石含量对纳米粒子-聚己内酯复合材料性能的影响

水热法合成纳米羟基磷灰石(HA)并将其分散在己内酯中,以其羟基为引发剂,在催化剂的作用下,引发己内酯开环聚合,制备纳米粒子-聚合物复合材料.NMR、DSC、XRD、PLM以及力学性能试验,探讨纳米粒子含量对复合材料的性能影响.随着纳米粒子含量的增加,聚己内酯(PCL)聚合度逐渐降低,在较高HA含量时,仍然存在较多的纳米粒子团聚;复合材料中PCL的结晶度基本不随纳米HA含量的变化而变化;HA含量为5wt%时,复合材料的断裂延伸率、抗拉强度以及压缩模量达到最大值;HA含量低于20wt%时,复合材料的弹性模量随着纳米粒子含量的增大而增加.     

nHA/PCL复合材料对成骨细胞增殖的影响

研究了纳米羟基磷灰石/聚己内酯(nHA/PCL)复合材料对成骨细胞的增殖的影响.制备了3种不同的nHA/PCL材料浸提液(3种材料中nHA/PCL质量比分别为0∶100,20∶80和40∶60).采用四唑盐比色法(MTT)检测不同的nHA/PCL材料浸提液对成骨细胞增殖率的影响.应用流式细胞术检测复合材料对成骨细胞周期的影响.结果表明:与对照组相比,实验组细胞增殖率和细胞各时期细胞数量均无显著性差异(p>0.05);研究表明:nHA/PCL浸提液对成骨细胞的增殖无不良影响,具有良好的细胞的相容性,其中40%nHA/PCL具有促进成骨细胞增殖指数的作用.     

骨组织工程用纳米羟基磷灰石／细菌纤维素的体外降解行为研究

将细菌纤维素浸泡在模拟体液中沉积而形成的纳米羟基磷灰石／细菌纤维素复合材料（nano-HA／BC）,被认为是在骨组织工程领域中理想的支架材料。从以下几方面分析nano-HA／BC在磷酸盐缓冲液（PBSl中浸泡不同时间后的降解行为及其相应的机制：材料的降解程度、nano．HA颗粒的稳定性和BC的结构变化。结果表明,nano-HA／BC在PBS溶液中浸泡-定时间后,nano-HA颗粒会逐渐溶解或脱落,水分子直接与BC纤维丝相互作用。在水分子和离子的作用下,BC的结晶度降低,BC分子链中分子间和分子内的结合力降低,甚至部分非结晶区内C-O-C键断裂。而C-O-C键的断裂是nHA／BC在PBS溶液中BC大分子降解的主要机制。研究结果对于研究骨组织工程支架材料nHA／BC的体内降解行为具有重要的指导意义。     

鳌合剂对溶胶凝胶制备纳米羟基磷灰石的影响

采用硝酸钙(Ca(NO3)2.4H2O)、磷酸三甲酯(PO(CH3O)3,简称TMP)作为钙与磷的先驱体,用溶胶凝胶法合成纳米羟基磷灰石粉体.探讨了工艺过程中添加乙二醇、柠檬酸、甘氨酸三种鳌合剂对粉体制备及其特性的影响.实验结果表明,在合适配比下,鳌合剂的加入影响干凝胶的形态,并促使碳酸钙晶相出现.柠檬酸和甘氨酸会改变体系pH值,影响酯的水解反应,同时通过鳌合作用及表面电荷作用影响粉体粒径.研究表明甘氨酸是低温下制备纳米羟基磷灰石粉体合适的鳌合剂.