含镁羟基磷灰石、磷酸三钙复合生物陶瓷涂层的研究

通过溶胶凝胶法在钛合金基体上合成了含镁羟基磷灰石/β-磷酸三钙陶瓷复合涂层．研究表明,羟基磷灰石相与β-磷酸三钙相共同存在于600℃烧结的复合涂层中．X射线光电子能谱分析显示,镁离子已合成到涂层之中．在模拟体液中,在复合涂层表面沉积出了较为明显的新生类骨层．使用MG63细胞进行培养试验,结果显示涂层具有良好的细胞亲和性．试验结果表明：含镁羟基磷灰石／β-磷酸三钙复合涂层具有良好的生物活性,有望在医疗实践中作为人工骨质材料得到广泛应用．     

含La羟基磷灰石生物活性膜层的制备与性能研究

采用微弧氧化法在含有乙酸钙、β-甘油磷酸钙、硝酸镧的电解液中在纯钛金属表面原位生成了多孔含La羟基磷灰石的生物涂层.用XRD、SEM、EDS、细胞培养等方法对膜层的厚度、物相、成分组成及生物相容性进行了研究.结果表明,膜层粗糙多孔,厚度在15μm左右,与钛基体之间无明显界面;膜层表面主要物相为含La的羟基磷灰石.细胞培养结果表明,膜层有良好的生物相容性.     

聚乳酸超细纤维膜的制备及降解性能研究

通过静电纺丝法制备了不同相对分子质量的聚乳酸和聚乳酸/羟基磷灰石(PLLA/HA)复合纤维膜。对纤维膜的微观结构、热性能及体外降解进行了分析。结果表明:实验中所制备的PLLA纤维膜具有珠串的微结构,经过体外降解后变成了多孔结构,该结构有利于细胞的吸附;PLLA/HA纤维复合膜中羟基磷灰石抑制了PLLA降解过程中的自催化作用,减缓了降解速率。     

电流对钛合金微弧氧化合成生物陶瓷膜的影响

提出了一种直接合成羟基磷灰石的方法,采用微弧氧化技术,在钛基体表面生长出一层致密的、结合良好的羟基磷灰石生物陶瓷膜,考察了微弧氧化电流对生成陶瓷膜的影响。并借助XRD、SEM等测试手段,研究了该生物陶瓷膜的物相组成和表面形貌特征。研究结果表明该生物陶瓷膜是具有双层结构的物相羟基磷灰石/二氧化钛(HAP/TiO_2)。     

二氧化钛与羟基磷灰石纳米复合材料制备与表征

通过在水溶液中将由磷酸氢氨和硝酸钙制得的“盐溶液”与由钛酸正丁酯和冰醋酸制得的“酯溶液”反应,并将产物在800 ℃下活化4 h,获得二氧化钛与羟基磷灰石的纳米复合物.用X射线衍射、红外光谱和透射电镜(TEM)对纳米复合物的组成和结构进行了研究.红外光谱显示了TiO2和PO4-3的两个特征峰,证实了纳米复合物由二氧化钛和羟基磷灰石组成.透射电镜表明,羟基磷灰石包覆在二氧化钛微晶颗粒的表面,形成颗粒尺寸约为100 nm的二氧化钛/羟基磷灰石复合物.X射线衍射图谱显示所得的二氧化钛与羟基磷灰石纳米复合物在2θ = 30°～35 °处出现3个新的衍射峰,说明纳米复合物的二氧化钛与羟基磷灰石界面上可能生成了分子复合物.     

针状硅灰石对磷酸盐骨水泥性能的影响

以磷酸氢二钾和磷酸二氢钾为固化液,以磷酸四钙、α-磷酸三钙、磷酸氢钙、焦磷酸钙、羟基磷灰石和碳酸钙为原料合成骨水泥,向其添加针状硅灰石,研究了针状硅灰石对其性能的影响。结果表明,在磷酸钙骨水泥中添加针状硅灰石可以缩短凝结时间,提高抗压强度。当针状硅灰石的添加量为3%,骨水泥性能达到最佳;其初凝时间、终凝时间分别为14和28 min,样品在Ringer’s模拟液溶液中浸泡2周后抗压强度达49.23 MPa,浸泡液的pH值变化幅度小(7.1~7.8),在安全范围之内。     

聚乳酸／硅灰石生物医用复合材料的降解性能

对聚乳酸/硅灰石这种新型的生物医用复合材料进行了研究.采用溶剂共沉淀法制备含不同质量分数硅灰石(5%,10%,20%和30%)的复合物材料并模压成型,测定其力学性能,包括拉伸强度和弯曲强度.结果表明,在聚乳酸基体中加入硅灰石,其力学性能有所下降,仅当硅灰石质量分数为10%时,拉伸强度略高于纯聚乳酸材料.选取含硅灰石10%的复合材料放入37.5°C恒温模拟体液中浸泡1,2,4,6,8,11,14,17,20,24及28周,考察其体外降解性能,包括质量损失、体系pH值变化及力学强度的变化.在降解过程中,聚乳酸/硅灰石复合材料降解速度较慢,并且保持相对较好的力学性能,适于应用在骨修复及骨组织工程领域.     

镁蔷薇辉石的生物活性

用溶胶-凝胶法制备出纯相镁蔷薇辉石(Ca3MgSi2O8)陶瓷,通过模拟体液浸泡和体外成骨细胞共培养对其体外生物活性进行了研究.XRD、SEM和EDS的结果表明,该陶瓷在模拟体液浸泡7 d后就在其表面沉积有碳酸羟基磷灰石(CHA),浸泡14 d后其表面出现呈蠕虫状结构结晶较好的碳酸羟基磷灰石.材料与细胞的共培养试验表明:与磷酸三钙(β-TCP)对比,该陶瓷更能促进成骨细胞的贴壁、黏附和铺展.     

钛合金生长羟基磷灰石的电镜分析

从生物相容性的角度考虑,羟基磷灰石(HA)是人体组织置换种植体最适合的陶瓷材料。但陶瓷和基体(钛合金)的相互关系,过渡层结构对该材料性能有重要影响。对界面的研究有助于更好的制备羟基磷灰石膜和研究羟基磷灰石在钛合金表面生长的机理。本文主要对基体、过渡层、羟基磷灰石做初步分析。过渡层上存在钛的一氧化物,羟基磷灰石的电镜照片与人骨的照片很相似。     

压力对均相共沉淀法制备羟基磷灰石晶体形貌的影响

以硝酸钙、磷酸氢二铵混合水溶液为原料、以尿素为缓冲剂,采用均相共沉淀法制备羟基磷灰石晶体,并通过X射线衍射、扫描式电子显微镜、透射电子显微镜等3种分析方法对样品分别进行了物相组成、晶体形貌、晶体取向的表征,研究了不同压力对羟基磷灰石晶体形貌的影响.结果表明:当反应压力从0.11 MPa增加至1.1 MPa时,所得羟基磷灰石晶体的物相组成由含有羟基磷灰石和磷酸八钙两种物相向只含有羟基磷灰石一种物相过渡;所得羟基磷灰石晶体的形貌从针状晶须（经由长板状和六方柱状）向薄片状晶体进行过渡;所得羟基磷灰石晶体的生长取向由沿一个方向（c轴）生长向沿另外两个方向（a轴和b轴）生长转变.     

In vitro biocompatibility assessment of a novel PRGD/PDLLA/NGF composite material

The objective of this study was to evaluate the degradability and biocompatibility of a novel composite materials which was grafted with RGD and immobilized with NGF(PRGD/PDLLA/NGF). The releasing of NGF, the biodegradability and cell-biocompatibility of PRGD/PDLLA/NGF membrane were evaluated in vitro. The experimental results showed that the NGF release process was prolonged over 30 days. Furthermore, the PRGD/PDLLA/NGF showed a better hydrophilicity, better biodegradation properties and cells affinity than PDLLA, which means a good support to adhesion and proliferate of Schwann cells. Therefore, the novel composite material holds considerable promise as scaffolds in nerve tissue engineering.     

Evaluation of a novel bioabsorbable PRGD/PDLLA/<Emphasis Type="Italic">β</Emphasis>-TCP/NGF composites in repair of peripheral nerves

Peripheral nerve regeneration using a novel nerve conduit (PRGD/PDLLA/β TCP/NGF) was evaluated, which was made of RGD peptide modified poly{(lactic acid)-co-[(glycolic acid)-alt-(L-lysine)]} (PRGD), poly(d,l-lactic acid) (PDLLA) and β-tricalcium phosphate (β-TCP). And the effectiveness was compared with that of PRGD/PDLLA/β-TCP, PDLLA and autograft in terms of nerve regeneration across a gap. Both of biodegradablity and cell-biocompatibility of the novel nerve conduit were evaluated in vitro. The results show that PRGD/PDLLA/β-TCP/NGF composite materials have better biodegradation properties and cell affinity than PDLLA, and could promote the RSC96 Schwann cells adhesion, proliferation and growth on the surface of materials. PRGD/PDLLA/β-TCP/NGF composite conduit was significantly superior to that of the PDLLA conduit in histological and axon morphologic index. PRGD/PDLLA/β-TCP/NGF conduit is more beneficial to nerve regeneration than PDLLA conduit. The biodegradable PDLLA/PRGD/β-TCP/NGF conduit has a good biocompatibility with rats tissue and it could effectively promote the nerve regeneration after bridging sciatic nerve defect of rats, the effect is as good as that of the autograft nerve, significantly superior to the PRGD/PDLLA/β-TCP conduit and PDLLA conduit. PDLLA/PRGD/β-TCP/NGF composite conduit is a potential ideal conduit. Funded by 973 State Key Fundamental Research and Development (No. G2005CB623905)     

PA6超微化及PA6／PP／硅灰石复合材料制备新方法

采用粒度分析,透射电镜观察,分子量测定及力学性能测试等手段研究尼龙6（PA6）及与内烯接枝马来酸酐（PP－g-MAH)和硅灰石混合的PA6在碾磨力场作用下的结构及力学性能的变化,实现了PA6的超微化,使用碾磨共混所得的PA6／PP－g-MAH／硅灰石混合微粉制备一PA6／PP硅灰石复合材料,研究表明,在碾磨力场作用下,PA6分子链发生断裂,粒度减小,最小可以达到80nm,碾磨过程中聚合物和填料之间的分散和相互作用使PA6／PP／硅灰石复合材料的力学性能增加,其屈服强度最高达到57MPa.     

PDLLA/HA/FK506复合神经导管的制备及体外降解性能

以聚乳酸（PDLLA）为基材、纳米羟基磷灰石（HA）为添加剂、加入免疫抑制剂FK506，用溶剂挥发法制备PDLLA／HA/FK506复合神经导管。通过观察复合导管在磷酸缓冲溶液中降解时pH值变化、质量损耗及材料微观形貌，研究了该复合导管的体外降解性能。结果表明：加入适量纳米羟基磷灰石可以改善聚乳酸降解的酸性问题并提高其力学强度。免疫抑制剂FK506的加入对导管材料的降解性能有一定的影响。PDLLA/HA／FK506复合神经导管具有良好的降解性能。     

硅灰石的改性及HDPE/硅灰石复合材料的研究

用硅烷偶联剂改性硅灰石,填充HDPE制备HDPE/硅灰石复合材料.从红外光谱、拉伸强度、冲击强度等方面对其性能进行了表征.结果表明:硅灰石经硅烷偶联剂改性能降低其表面能,提高其疏水性,用量为硅灰石质量1.3%～2%为宜;改性硅灰石填充HDPE能提高复合材料的弯曲强度和抗冲击强度,但降低了复合材料的拉伸强度,填充量以30%为宜.     

Preparation and Degradation Characteristics of Poly （d,l-lactide） Composite Films

PDLLA/CHI/β-TCP/NGF composite films were prepared by a solvent evaporation method. The degradation characteristics of the poly （d, l-lactide） composite films were studied in vitro and in vivo. The acidity produced by poly （d, l-lactide） materials was not obvious. Adding chitosan and β-TCP can relieve the acidity problem and improve strength performance of films. The NGF has influences on the degradation characteristics of films. It is verified that PDLLA/CHI/β-TCP/NGF composite films prepared by solvent evaporation method have excellent degradation characteristics. It can be used as a perfect biomaterial for repairing nerve injuries.     

BIODEGRADATION AND MECHANICAL PROPERTIES OF HYDROXYAPATITE/POLY-DL-LACTIDE COMPOSITES FOR FRACTURE FIXATION

The biodegradation and mechanical properties of self-designed hydroxyapatite/poly-DL-lactide (HA/PDLLA) compositites -were investigated in vitro and invio. In vitro, the specimens of HA/PDLLA and unfilled PDLLA -with similar molecular weights were immersed in phosphate-buffered saline. Ageing of the various devices were monitored by measuring molecular weight,water absorption, weight loss, PH, mechanical strengths and mi-crostructural changes. The follow-up times were 2, 4 , 6 , 8, 10 and 12 weeks. In vivo, a transverse transcondylar osteotomy of the distal femur was fixed with a HA/PDLLA rod (diameter, 4. 5mm;length, 30-40mm). The follow-up times were 3. 6 and 12 weeks. Roentgenographic, histologic, and biomechanical studies were carried out. The results show that the HA/PDLLA composities have higher mechanical strength and slower degradation than that of the unfilled PDLLA and that of all osteotomies unite within six weeks without delay. Consequently, the HA/PDLLA composites possess sufficient mechani     

Preparation and Charactcrization of a Novel PDLLA/Chondroitin Sulfate/Chitosan Asymmetry Film

A novel bioactive and bioresorbable asymmetry film was prepared,The PDLLA membrane was activated by 1,6-hexanediamine to obtain a stable positive charge surface.Chondroitin sulfate and chitosan were then deposited on activated PDLLA membrane via layer-by-layer(LBL)electro-static assembly (ESA)technique.The deposition process was monitored by UV-Vis absorbance spectroscopy.The composite membrane was frozen lyophilized to form the asymmetry film and characterized by attenuated total reflectic (ATR)-FT-IR,XPS and SEM.The experimental results show that a stable 1,6-hexanediamme layer on PDLLA substrate based on the aminolysis of the polyester and the layer thickness increase linearly first with the increase of the deposited layers,and then increases slowly due to the layer interpenetration.The test results of ATR-FT- IR and SEM show the asymmetry film is modified uniformly with a dense inner layer and a porous sponge outer layer.     

接枝聚丙烯对羟基磷灰石填充聚丙烯的增容作用

采用固相接枝法制备了聚丙烯（PP）接枝马来酸酐（MAH）；采用熔融接枝法制备了PP接枝MAH，PP接枝十一烯酸，PP接枝蓖麻油。用化学滴定法和红外光谱对接枝物进行了表征。结果表明，三种单体均能接枝到PP上，并且MAH固相接枝的接枝率高于熔融接枝的接枝率。以上述四种PP接枝物作相容剂，羟基磷灰石、碳酸钙、硅灰石作填料，制备了PP／无机粉体填充复合材料，比较了不同增容剂和不同填料对复合材料性能的影响，结果表明，PP接枝十一烯酸的增容作用最强，而硅灰石填充复合体系力学性能最好。