溶胶–凝胶法制备高比表面积铝磷钙生物活性玻璃（英文）

采用溶胶–凝胶法,在不使用模板剂的情况下制备出高比表面积的介孔CaO-Al_2O_3-P_2O_5生物活性玻璃(MBGs),用BET、XRD、DTA以及FTIR对MBGs的结构进行了表征,并用生物模拟体液(SBF)在36.5℃对生物玻璃进行了体外活性测试,测试时间为1 d、3 d、7 d和14 d。介孔玻璃的比表面积最高达到461.1 m2/g,随着CaO的含量从5mol%增加到30mol%,介孔玻璃的比表面积呈降低趋势。用XRD和FTIR验证了材料的玻璃结构。然而,在生物模拟体液(SBF)实验中,当CaO摩尔含量达到20mol%时,介孔玻璃表现出较高生物活性。这种特殊的高比表面积的介孔铝磷钙生物活性玻璃在生物医药方面有潜在的应用价值。本文的实验结果对优化生物玻璃的介孔结构和CaO含量来提升玻璃的生物活性有一定的指导意义。     

纯钛表面立方介孔SiO2薄膜诱导沉积碳磷灰石层

采用浸渍-提拉法在预处理纯钛表面制备立方介孔SiO₂薄膜, 通过评价体外诱导类骨碳磷灰石层形成能力研究其生物活性。利用小角X射线衍射、傅立叶变换红外光谱、N₂吸附、电镜和能谱等测试技术对模板剂去除前后、模拟体液浸泡前后介孔薄膜结构、组成与形貌进行了研究; 利用固体表面Zeta电位仪研究薄膜表面荷电性质。结果表明, 介孔薄膜具有三维立方介孔结构, 在模拟体液(1.5SBF)中浸泡14 d即能诱导碳磷灰石层在其表面沉积, 显示出良好的生物活性。介孔薄膜独特的孔道结构以及孔表面Si-OH在体液中呈负电性对其生物活性起关键作用。     

生物活性玻璃/PLA-PEG-PLA/聚乳酸组织工程支架在SBF溶液中的降解和矿化

通过测定pH值、质量损失率、SEM、XRD和FTIR,系统研究了生物活性玻璃/聚乳酸-聚乙二醇-聚乳酸嵌段共聚物（PLA-PEG-PLA）/聚乳酸组织工程支架在模拟体液（SBF）中的降解和生物矿化性能。研究结果表明：随着支架在SBF溶液中浸泡时间的延长,SBF的pH值和支架的质量呈下降趋势;生物活性玻璃的存在使pH值升高,而PLA-PEG-PLA嵌段共聚物的存在使pH值降低。XRD、FTIR图谱和SEM图像表明：在SBF中浸泡一定时间后,有无定型或结晶不完善的磷灰石在生物活性玻璃/PLA-PEG-PLA/聚乳酸组织工程支架表面沉积形成,并且PLA-PEG-PLA共聚物降解速度比聚乳酸快;在SBF中浸泡7天后,PLA-PEG-PLA共聚物的含量已经很难通过FTIR检测出来。     

CaO-P2O5-SiO2溶胶凝胶玻璃在模拟体液中HCA层形成的研究

采用溶胶凝胶法制备了高硅含量的CaO-P2O5-SiO2系统玻璃.组成范围为(mol%)CaO13～18,P2O5 3～6,SiO2 78～83.样品采用体外溶液实验(in vitro)方法,在模拟体液(SBF)内浸泡不同时间.通过测定样品在SBF浸泡不同时间的溶液pH值变化,并对样品采用XRD、SEM等测试技术,研究了样品表面碳酸羟基磷灰石(HCA)层的形成机理及形貌变化.结果表明SiO2含量达78～83 mol%时玻璃仍具有很高的生物活性.玻璃表面在SBF中24 h内已开始形成HCA层,第3天已呈稳定态并布满整个表面,浸泡10d后的HCA由粒径在0.5～2.0 μm的球形颗粒构成.球形颗粒是纳米级HCA微晶聚集而成的多晶体.     

BaTiO3-ZnNb2O6陶瓷介电及储能性能研究

采用固相法制备(1-x)BaTiO₃-xZnNb₂O₆ (x=0.5mol%, 1mol%, 1.5mol%, 2mol%, 3mol%, 4mol%) (简称BTZN)陶瓷, 研究了BTZN陶瓷的烧结温度、结构、介电性能和铁电性能。BTZN陶瓷烧结温度随着ZnNb₂O₆含量增加逐渐降低。XRD结果表明当ZnNb₂O₆含量达到3mol%时出现第二相Ba₂Ti₅O₁₂。介电测试结果表明随ZnNb₂O₆含量的增加, BTZN陶瓷介电常数逐渐减小, 而介电常数的频率稳定性逐渐增强。介电温谱表明所有BTZN陶瓷均符合X8R电容器标准。BTZN陶瓷的极化强度值随着ZnNb₂O₆含量的增加逐渐降低。当x=4mol%时, BTZN陶瓷获得240 kV/cm的击穿电场和1.22 J/cm ³的可释放能量密度。     

溶胶-凝胶生物活性玻璃纤维的制备及其体外矿化性能研究

采用溶胶-凝胶法制备出CaO-P2O5-SiO2系统生物活性玻璃纤维．通过倒置相差显微镜、SEM、FTIR等测试手段考察了生物活性玻璃纤维的微观形貌和显微结构；采用生物材料的体外实验方法以及XRD、SEM、FTIR等测试手段研究了生物活性玻璃纤维在模拟生理体液（SBF）中浸泡后的表面反应产物的形成机理、结晶程度和微观形貌．结果表明，这种生物活性玻璃纤维是一种不连续的短纤维，具有较好的纤维形态和较高的生物活性，在短时间内即可在模拟生理体液（SBF）中形成茸毛状A类碳酸羟基磷灰石（HCA）层．     

稀土掺杂对ZnO-B2O3-SiO2玻璃热稳定性及结构的影响

为了探索镧系与非镧系元素对ZnO-B₂O₃-SiO₂系统玻璃热稳定性及结构的影响, 本研究采用差示扫描量热仪(DSC)和傅立叶变化红外光谱仪(FTIR)开展了La₂O₃和Y₂O₃掺杂对该系统玻璃析晶行为、热稳定性和结构变化的系统研究。结果表明: 当La₂O₃掺杂量大于8mol%、Y₂O₃掺杂量大于6mol%时, 60ZnO-30B₂O₃-10SiO₂系统玻璃开始出现析晶现象; 当La₂O₃掺杂量为4mol%、Y₂O₃掺杂量为2mol%时, 该玻璃的热稳定性能最好。结构研究表明, 少量添加稀土氧化物会使该系统玻璃的网络链接程度提高, 而当掺杂量超过一定量时会使该系统玻璃的网络链接程度降低。     

生物活性玻璃/聚乳酸组织工程支架在SBF溶液中的降解和矿化性能

利用扫描电镜、X衍射仪以及红外漫反射仪,并通过对生物活性玻璃/聚乳酸组织工程支架在模拟体液（SBF）中失重率及模拟体液pH值的变化的检测,系统研究了生物活性玻璃/聚乳酸组织工程支架在SBF中的降解和矿化性能。结果发现：随着含有生物活性玻璃的聚乳酸支架在SBF溶液中浸泡时间的增长,SBF的pH值不断下降;含有生物活性玻璃...     

羟基磷灰石/聚己内酯-壳聚糖复合材料的制备与表征

为提高复合材料的力学性能和生物活性以聚己内酯(PCL) 、壳聚糖(CS) 、羟基磷灰石(HA)为原料,用Hakke流变仪挤出成型制备了不同 HA含量的HA/ PCL-CS复合材料,并对其进行了拉伸性能的测试,考察了复合材料浸渍于模拟体液(SBF)中的生物活性及其在生理盐水中的降解性能,用X射线衍射(XRD) 、傅里叶变换红外光谱(FTIR) 、扫描电镜(SEM) 、接触角测试仪对材料进行了表征。结果表明：复合材料的拉伸强度和断裂伸长率随 HA含量的增加而降低,而杨氏模量随 HA含量的增加而升高;亲水性能随着HA含量的增加而提高; HA/PCL-CS复合材料在模拟体液(SBF)中浸渍 14d后,在表面形成一层弱结晶的碳磷灰石(CHA)覆盖层 , 显示出良好的生物活性; PCL 的分子量随着降解时间的延长而降低,溶液pH值和质量损失率却增大,浸渍28d后,溶液pH值达到9. 54,失重率达到5.86%,显示出良好的生物可降解性。     

聚乙二醇聚合度对介孔η-Al2O3纤维形貌及吸附能力的影响

分别以2种不同聚合度的聚乙二醇（PEG）PEG600和PEG2000为模板导向剂,采用水热法合成η-Al₂O₃（PEG600）和η-Al₂O₃（PEG2000）介孔纤维,借助XRD、TEM和N₂吸附测试对材料进行表征,研究了PEG聚合度对介孔η-Al₂O₃纤维性质的影响。通过静态吸附平衡实验考察了介孔η-Al₂O₃纤维对亚甲基蓝的吸附特性。结果表明：2种模板导向剂均可用于合成介孔η-Al₂O₃纤维。PEG聚合度对介孔结构、比表面积、孔体积和孔径有较大影响。η-Al₂O₃（PEG600）的比表面积和孔体积分别为189.899 m²·g^-1和0.329 cm³·g^-1,分别是η-Al₂O₃（PEG2000）的1.4倍和1.2倍,平均孔径也比η-Al₂O₃（PEG2000）的大。2种介孔η-Al₂O₃纤维对亚甲基蓝的吸附机制均为多分子层吸附。根据BET多层分子吸附方程计算得η-Al₂O₃（PEG600）和η-Al₂O₃（PEG2000）对亚甲基蓝的平衡吸附量分别为256.391 3 mg·g^-1和204.045 9 mg·g^-1。     

介孔生物玻璃/磷酸钙骨水泥多级孔复合支架的制备及其载药特性研究

采用离心法将介孔生物活性玻璃(MBG)和磷酸钙骨水泥(CPC)高效复合制备出介孔/大孔多级孔复合支架材料, 评价了其对抗癌药物阿霉素的装载及释放性能。实验结果表明, 采用离心法能在大孔支架CPC内有效负载大量的介孔生物活性玻璃, 使其比表面积高达100.1 m²/g, 负载量达47.2%, 而采用传统浸渍法则不能将MBG粉体材料负载于CPC支架上。载药实验发现离心法制备的介孔/大孔复合支架对阿霉素的装载量达到了46 mg/g, 是普通大孔CPC支架的11.5倍, 且在体外具有药物缓释的特性。     

硼硅酸盐生物活性玻璃在直流电场下的体外矿化性能

硼硅酸盐生物活性玻璃具有良好的生物活性和骨传导性, 但大多数生物活性玻璃表现出非线性降解和矿化行为, 矿化性能会随着时间而减缓。电场作为一种外场辅助调节的方法, 能够干预玻璃的离子交换和扩散。本研究利用直流电场干预硼硅酸盐生物活性玻璃的体外矿化, 加快降解较慢阶段中硼硅酸盐生物玻璃的生物活性。将熔融法制备的成分为18SiO₂-6Na₂O-8K₂O-8MgO-22CaO-2P₂O₅-36B₂O₃的硼硅酸盐生物活性玻璃浸泡在SBF生理模拟液中, 施加0~90 mA的电流, 研究直流电场对硼硅酸盐生物玻璃降解及体外矿化性能的影响。研究结果表明, 施加电场不仅可以提高硼硅酸盐生物活性玻璃的降解率和离子释放量, 而且有利于玻璃网络水解和表面羟基化, 加速羟基磷灰石的生成。其中失重率比对照组提高了3%~5%, 硼和钙的离子释放量分别较对照组提高了2.3~2.9倍和1.9~2.3倍。对硼硅酸盐生物活性玻璃表面结构分析得出, 暴露在电场下的样品表面生成了磷灰石层。应用直流电场可以提高生物活性玻璃的降解及体外矿化性能, 为提升骨修复效果提供了一种新思路。     

Local structures of mesoporous bioactive glasses and their surface alterations in vitro: inferences from solid-state nuclear magnetic resonance

We review the benefits of using (29)Si and (1)H magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy for probing the local structures of both bulk and surface portions of mesoporous bioactive glasses (MBGs) of the CaO-SiO(2)-(P(2)O(5)) system. These mesoporous materials exhibit an ordered pore arrangement, and are promising candidates for improved bone and tooth implants. We discuss experimental MAS NMR results from three MBGs displaying different Ca, Si and P contents: the (29)Si NMR spectra were recorded either directly by employing radio-frequency pulses to (29)Si, or by magnetization transfers from neighbouring protons using cross polarization, thereby providing quantitative information about the silicate speciation present in the pore wall and at the MBG surface, respectively. The surface modifications were monitored for the three MBGs during their immersion in a simulated body fluid (SBF) for intervals between 30 min and one week. The results were formulated as a reaction sequence describing the interconversions between the distinct silicate species. We generally observed a depletion of Ca(2+) ions at the MBG surface, and a minor condensation of the silicate-surface network over one week of SBF soaking.     

The effect of Sr concentration on bioactivity and biocompatibility of sol–gel derived glasses based on CaO–SrO–SiO2–P2O5 quaternary system

In the present study, sol–gel derived glasses based on CaO–SrO–SiO₂–P₂O₅ system were prepared and the effect of Sr concentration on in vitro bioactivity and cellular properties of the glasses were investigated. SrO was substituted for CaO in the glass formula up to 10 mol% and in vitro bioactivity of the samples was evaluated by soaking them in simulated body fluid followed by structural characterization using XRD, FTIR and SEM techniques. The effects of various glass compositions on proliferation and differentiation of osteoblastic cells were also evaluated. The results showed that the substitution of Sr for Ca in the glass composition retarded formation of apatite layer onto the glass surfaces. Morphologies of the apatite layers were also different in which abundance of the crystals decreased with increasing Sr concentration. The bioactive glasses did not exert cytotoxic effect on the cells, however the proliferation and alkaline phosphatase activity of the cells on the samples containing low doses of Sr were higher than those of control and the samples with high dose of Sr. Glass specimen with 5 mol% of Sr exhibited appropriate bioactivity with optimal cell proliferation and ALP activity.     

Influence of SrO substitution for CaO on the properties of bioactive glass S53P4

Commercial melt-quenched bioactive glasses consist of the oxides of silicon, phosphorus, calcium and sodium. Doping of the glasses with oxides of some other elements is known to affect their capability to support hydroxyapatite formation and thus bone tissue healing but also to modify their high temperature processing parameters. In the present study, the influence of gradual substitution of SrO for CaO on the properties of the bioactive glass S53P4 was studied. Thermal analysis and hot stage microscopy were utilized to measure the thermal properties of the glasses. The in vitro bioactivity and solubility was measured by immersing the glasses in simulated body fluid for 6 h to 1 week. The formation of silica rich and hydroxyapatite layers was assessed from FTIR spectra analysis and SEM images of the glass surface. Increasing substitution of SrO for CaO decreased all characteristic temperatures and led to a slightly stronger glass network. The initial glass dissolution rate increased with SrO content. Hydroxyapatite layer was formed on all glasses but on the SrO containing glasses the layer was thinner and contained also strontium. The results suggest that substituting SrO for CaO in S53P4 glass retards the bioactivity. However, substitution greater than 10 mol% allow for precipitation of a strontium substituted hydroxyapatite layer.     

基于介孔硼硅酸盐生物活性玻璃微球的可注射复合骨水泥

以溶胶-凝胶法制备的介孔硼硅酸盐生物活性玻璃微球(MBGS)作为固相, 海藻酸钠(SA)溶液作为液相,开发了一种可注射复合骨水泥。对MBGS中氧化硼/氧化硅的比例对其质构性能及骨水泥的可操作性、抗压强度和生物活性的影响进行表征。实验结果表明, 随着硼含量的增加, MBGS的比表面积从161.71 m²/g增大至214.28 m²/g, 平均孔径以及总孔容也随之增长, 加速了玻璃相中钙离子的释放, 使得玻璃与SA的快速交联, 改善了骨水泥可操作性能和力学性能, 凝固时间由21 min缩短至9 min, 抗压强度由3.4 MPa提升至4.1 MPa, 体外矿化性能也随之提高。综合各方面性能表现, BC-30骨水泥兼具良好的可操作性能、力学性能和体外矿化能力, 是最合适的骨水泥组分。总之, 提高MBGS的质构性能是增强复合骨水泥的可操作性、抗压强度和生物活性的有效方法。     

Sol–gel-derived manganese-releasing bioactive glass as a therapeutic approach for bone tissue engineering

Sol–gel processing allows the production of bioactive glasses (BG) with flexible compositions and the incorporation of different metallic ions with therapeutic benefits into the glass network. Manganese is among several previously studied therapeutically beneficial ions and has been shown to favour osteogenic differentiation, in addition to playing an important role in cell adhesion. The incorporation of Mn into bioactive glasses for tissue engineering has been previously conducted using the conventional melting route, whereas the sol–gel route has not yet been explored. Sol–gel technology has great versatility, allowing the preparation of BG with various compositions, sizes, morphologies and a large surface area that could provide improved cellular responses and enhanced bioactivity when compared to melt-derived glasses. In this context, this work developed new compositions of sol–gel bioactive glasses (on the SiO₂–P₂O₅–CaO–MnO system) and explored the effects of incorporating MnO on the structure, texture, in vitro bioactivity and cytocompatibility of these materials. Our results show that Mn-containing bioactive glasses present an amorphous character, high surface area and mesoporous structure. The formation of a hydroxycarbonate apatite (HCA) layer after immersion in simulated body fluid (SBF) revealed the high bioactivity of the glasses. Ion release evaluation indicated that the Si, Ca, P and Mn release levels could be adjusted within therapeutic limits, and cytotoxic analysis demonstrated that the ionic products of all samples generated a cell-friendly environment. Therefore, Mn incorporation into the bioactive glass network appears to be a potential strategy to develop superior materials with sustained ion release for tissue engineering.     

Alkali oxide containing mesoporous bioactive glasses: Synthesis,characterization and in vitro bioactivity

We report, for the first time, the synthesis of sodium oxide containing mesoporous bioactive quaternary glasses and compared with two different mesoporous ternary silicate systems by modified sol–gel process. With the aid of three different glass systems, a systematic analysis has been made on phosphorous-bearing (P-bearing) and phosphorous-free (P-free) mesoporous bioactive glasses to investigate the role of phosphorus on in vitro bioactivity of various silicate glasses with constant alkali oxide content. The combined use of multiple analytical techniques XRD, FTIR, SEM, nitrogen adsorption/desorption analysis before and after soaking in the SBF solution allowed us to establish strong correlation between composition, pore structure and bioactivity. We find that the P-bearing mesoporous glasses show the rapid hydroxycarbonate apatite (HCA) crystallization than P-free mesoporous glasses independent of calcium content. The present study reveals that the presence of phosphorous jointly with calcium in the bioactive glass system significantly enhances the rate of apatite formation as well as crystallization of apatite phase. Additionally, we find that a glass with sodium orthophosphate rich phase enhances the solubility when immersed in SBF and further accelerate the kinetics of apatite formation. The influences of the chemical composition and their superior textural properties on bioactivity are explained in terms of the unique structure of mesoporous bioactive glasses.     

SPS烧结制备生物活性镁黄长石陶瓷

钙硅基生物陶瓷具有良好的生物活性和细胞相容性, 在生物医疗领域具有广阔的发展前景。但是其粉体烧结性能差的缺点导致很难获得致密的陶瓷材料, 阻碍了其应用的进程。本研究采用化学共沉淀法制备了纯度高且烧结活性好的镁黄长石粉体, 然后采用放电等离子烧结技术(SPS)制备了镁黄长石陶瓷材料。通过X射线衍射(XRD)和扫描电子显微镜(SEM)表征了样品的组成结构和显微形貌, 并通过阿基米德法和模拟体液浸泡法分析了镁黄长石陶瓷样品的致密度和生物活性。研究结果表明, 采用SPS技术在1170℃、70 MPa保温5 min条件下可获得致密度超过99%的镁黄长石陶瓷材料。在模拟体液中浸泡3 d, 陶瓷样品表面出现磷酸盐的沉积, 浸泡7 d后生成了类骨羟基磷灰石, 说明SPS技术制备的致密镁黄长石生物陶瓷具有良好的诱导沉积类骨磷灰石能力。     

Synthesis of CaO–SiO<Subscript>2</Subscript>–P<Subscript>2</Subscript>O<Subscript>5</Subscript> mesoporous bioactive glasses with high P<Subscript>2</Subscript>O<Subscript>5</Subscript> content by evaporation induced self assembly process

Mesoporous bioactive glasses (MBGs) of the CaO–SiO₂–P₂O₅ system containing relatively high P₂O₅ contents (10–30 mol%) were prepared from a sol–gel. An evaporation-induced self-assembly (EISA) technique was used with poly(ethylene oxide)-block–poly(propylene oxide)-block–poly(ethylene oxide) (EO₂₀–PO₇₀–EO₂₀, P123) acting as a template. The structural, morphological and textural properties of MBGs were investigated by small-angle X-ray diffraction (SAXRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and a N₂ sorption/desorption technique. SAXRD and TEM results display the reduced long-range ordering of mesopores with increasing P₂O₅ content. N₂ sorption/desorption analysis shows that all three samples exhibit a type IV isotherm with type H1 hysteresis loops, characteristic of independent cylindrical slim pore channels and this material has a Barret–Joyner–Halenda (BJH) model pore size of ~4 nm and BET specific surface area ~430 m²/g. NMR results indicate a more condensed framework for samples with 30 mol% P₂O₅ than samples with 10 mol% P₂O₅. For in vitro bioactivity tests where samples were soaked in simulated body fluid (SBF), samples with 30 mol% P₂O₅ showed higher crystallinity than those with lower P₂O₅ contents Silicon concentration increased in SBF solution during the soaking period, which indicates MBGs can be degradable in SBF solution.