溶胶凝胶法合成含锌羟基磷灰石粉体

以Ca(NO3)2·4H2O、P2O5和Zn(N03)2·6H2O的乙醇溶液为原料,用溶胶凝胶法合成含锌羟基磷灰石(Zn-HA)粉体.采用X-射线衍射(XRD)、透射电镜(TEM)、红外光谱(FTIR)、热重差热(TG-DTA)对Zn-HA的晶相、形貌、化学组成和热稳定性进行了分析.结果表明:锌取代部分钙进入HA的晶格中降低了磷灰石的颗粒尺寸;当锌含量低于40%时,不会改变HA的晶体结构,但因锌离子半径小于钙离子半径,导致HA的结晶度降低,微晶尺寸减小.TG-DTA分析表明,锌掺入降低姒的热稳定性.     

不锈钢表面羟基磷灰石涂层的溶胶凝胶法制备

在316L不锈钢基体表面采用溶胶-凝胶法和多次提拉法涂覆羟基磷灰石(HA)涂层并对涂层进行了物相、形貌、结合力和耐腐蚀性能的表征,研究了退火温度对涂层性能的影响.结果表明,经400～500℃退火处理,能形成晶化程度不高、晶粒细小的多孔结构羟基磷灰石涂层;升高退火温度可提高HA晶化程度和界面结合力;HA涂层提高了不锈钢的抗侵蚀能力.     

复合TiO2对溶胶凝胶法制备羟基磷灰石晶化的影响

利用溶胶凝胶法,将由前驱盐制备的羟基磷灰石(HA)和TiO2溶胶直接混合,经干燥、热处理制备了含TiO2的复合羟基磷灰石材料,采用X射线衍射分析了复合TiO2对HA晶化过程的影响,通过对XRD衍射数据的计算,研究了复合TiO2对HA晶粒尺寸和结晶度的影响.结果表明,复合TiO2延缓了HA的结晶,使其晶粒长大,促进HA的分解;复合HA的晶粒直径小于100 nm,且结晶度在1000 ℃左右可达到90%.     

钛表面预处理对溶胶-凝胶法制备羟基磷灰石涂层的影响

利用溶胶-凝胶法在工业纯钛表面制备羟基磷灰石（HA）涂层，探讨了酸洗和浓碱热处理两种基体预处理工艺对涂层的影响；用接触角仪测量了涂覆前两种预处理后基体的接触角并计算其表面能；用扫描电镜（SEM）、X射线衍射仪（XRD）分析了基体和涂层的表面、截面形貌及成分。结果表明：通过溶胶-凝胶法，在基体表面涂覆了HA涂层；与酸洗基体相比，浓碱热处理后在钛表面生成了网状多孔的钛酸钠水凝胶层，提高了基体的表面活性及表面能，由酸洗后的57．68mJ·m^-2增加到浓碱热处理后的77．34mJ·m^-2，尤其是极性色散比由0．235增至0．727，有利于HA在其表面涂覆，减少了提拉次数且HA涂层致密、厚度均匀约为3μm；提高了涂层与基体的结合力。     

溶胶-凝胶法在钛表面制备钛/羟基磷灰石生物涂层

以硝酸钙和五氧化二磷为前躯体,使用溶胶-凝胶法制备出羟基磷灰石,并使用浸渍提拉法在纯钛表面合成羟基磷灰石涂层.使用XRD对涂层中的相结构进行分析,以确定不同加热温度以及不同涂层层数对羟基磷灰石涂层性能的影响.结果表明:随加热温度升高,羟基磷灰石的结晶度和体积分数先升后降.在800℃下,羟基磷灰石的结晶度最高,体积分数也...     

兔肝脏中羟基磷灰石-阿霉素缓释剂的释放

目的 观察羟基磷灰石-阿霉素抗癌复合物局部注射,阿霉素在体内的释放过程及其抗肿瘤作用。方法 在B 超引导下向兔肝左叶内注入羟基磷灰石-阿霉素抗癌复合物。应用荧光分光光度仪测定注射羟基磷灰石-阿霉素抗癌复合物后,阿霉素在组织及血浆中的浓度,并与无羟基磷灰石的对照组比较。结果 此复合药物可在组织中维持有效治疗浓度1000 ng·g^-15 d 左右,同时与对照组相比注射后即时外周血浆浓度下降约1/2 。结论 该复合药物局部应用可提高及维持组织有效治疗浓度,减少毒副作用。     

钾对羟基磷灰石晶须的形貌及热稳定性的影响

通过α-TCP水化法制备了HA晶须,并通过向原料中添加KOH的方法来提高所制备晶须的热稳定性。结果表明:K的引入对HA晶须形貌有较大影响,K添加量过大时会抑制晶须的生长;同时,K的引入可以有效提高所制备晶须的热稳定性,相对于不添加K的HA晶须,添加适量K的晶须在1000℃下热处理2h后依然能较好的保持晶须形貌,X射线衍射和热分析结果发现此时仅有少量HA发生分解生成β-TCP,主晶相仍为HA。     

Sol-Gel法合成纳米羟基磷灰石及晶粒生长、结晶度的研究

以Ca(NO3)2·4H2O与H3PO4为前躯体,采用溶胶-凝胶法制备出纳米羟基磷灰石(HA)粉体。通过差热分析仪、X-射线衍射仪、SEM对HA粉体及烧结体进行了表征和分析,采用阿基米德排水法测试了样品密度。结果表明:粒径分布均匀、呈球形、团聚极少,a轴方向和c轴方向的晶粒尺寸分别为10~30nm和20~50nm,随着温度的升高颗粒的尺寸和结晶度增大。600℃烧结2h得到纯度高、晶化好的HA;800和900℃烧结样品中出现的少量Ca3(PO4)2和CaO是由于HA的分解和含磷前躯体的挥发所致。     

羟基磷灰石涂层及其热处理对TLM合金基体的影响

利用DTA/TG、XRD方法研究溶胶凝胶法制备羟基磷灰石(HA)烧结热处理过程中的相转变规律,同时研究制备HA涂层时保温处理对TLM(TiZrSnMoNb系)合金基体力学性能的影响.结果表明,在制备HA涂层的过程中.热处理温度为450～1000℃,所得的HA的晶化程度较高,较纯净.     

煅烧对羟基磷灰石微球孔隙特征的影响

研究煅烧温度和保温时间对羟基磷灰石微球孔隙特征的影响,分别用比表面积-孔隙率分析仪,扫描电镜对其孔隙特征进行表征。结果表明,随煅烧温度增加,羟基磷灰石微球的孔径尺寸逐渐增加,但孔体积逐渐降低;当煅烧温度为500℃时,孔径尺寸随着保温时间的增加而呈现逐渐增大的趋势,而孔体积则有降低趋势,但是总体变化不大。     

Preparation and characterization of nano hydroxyapatite sol

Nano hydroxyapatite has special biological effects when it interacts with cells. The method of preparation of nano hydroxyapatite crystals in water and the stability of hydroxyapatite sol are reported. Nanometer sized hydroxyapatite crystals were synthesized by precipitation with monocalcium phosphate and calcium hydroxide. The size of the crystals is 30 - 50 nm as determined by laser light scattering and transmission electron microscopy (TEM). The shape of the crystals particles is either sphere or rod-shaped. Beijing Synchrotron Radiation Facility (BSRF) micro-probe X-ray fluorescence analysis and TEM analysis reveal that hydroxyapatite crystals can pass human liver cancer cell membrane in the form of particles.     

Inhibition mechanism of aspartic acid on crystal growth of hydroxyapatite

The effects of aspartic acid on the crystal growth, morphology of hydroxyapatite（HAP） crystal were investigated, and the inhibition mechanism of aspartic acid on the crystal growth of hydroxyapatite was studied. The results show that the crystal growth rate of HAP decreases with the increase of the aspartic acid concentration, and the HAP crystal is thinner significantly compared with that without amino acid, which is mainly due to the （10^-10） surface of HAP crystal being inhibited by the aspartic acids. The calculation analysis indicates that the crystal growth mechanism of HAP, following surface diffusion controlled mechanism, is not changed due to the presence of aspartic acid. AFM result shows that the front of terrace on vicinal growth hillocks is pinned, which suggests that the aspartic acid is adsorbed onto the （10^-10） surface of HAP and interacts with the Ca^2＋ ions of HAP surface, so as to block the growth active sites and result in retarding of the growth of HAP crystal.     

纳米羟基磷灰石的精氨酸表面修饰与铕掺杂及其细胞活性

采用水热合成法制备经精氨酸表面修饰和铕掺杂的羟基磷灰石纳米颗粒（HAP-Eu）。利用透射电镜（TEM）、Zeta电位分析仪、傅立叶红外光谱仪和X射线衍射（XRD）对HAP-Eu的成分、形貌、结构、晶粒粒径和Zeta电位进行表征,并通过成像流式细胞仪研究细胞活性。结果表明：制备的HAP-Eu粒径较均匀,约为100nm,特征峰明显;在pH=7.5时,颗粒的表面净电荷均值约为30.10mV;在人上皮细胞和内皮细胞中无毒性。     

Preparation and properties of a cerium-containing hydroxyapatite coating on commercially pure titanium by micro-arc oxidation

A porous cerium-containing hydroxyapatite coating on commercially pure titanium was prepared by micro-arc oxidation （MAO） in an electrolytic solution containing calcium acetate, p-glycerol phosphate disodium salt pentahydrate （β-GP）, and cerium nitrate. The thickness, phase, composition morphology, and biocompatibility of the oxide coating were characterized by X-ray diffraction （XRD）, electron probe microanalysis （EPMA）, scanning electron microscopy （SEM） with energy dispersive X-ray spectrometer （EDS）, and cell culture. The thickness of the MAO film is about 15-25 ~tm, and the coating is porous and uneven, without any apparent interface to the titanium substrates. The results of XRD and EDS show that the porous coating is made up of hydroxyapatite （HA） film containing Ce. The favorable osteoblast cell affinity makes the Ce-HA film have a good biocompatibility. The Ce-HA film is expected to have significant medical applications as dental implants and artificial bone joints.     

Preparation of hydrophobic anodic film on AZ91D magnesium alloy in silicate solution containing silica sol

Anodic films were prepared on the AZ91D magnesium alloy in the electrolyte of 1.0 M Na₂SiO₃ with and without the addition of silica sol under the constant current density of 20 mA/cm² at 60 °C. The anodic films were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that the two main constituents of the anodic films were silicon and oxygen. However, no crystal compound including either silicon or oxygen could be detected by the XRD patterns. The addition of 10 vol.% silica sol increased the thickness of the anodic film and improved the roughness of the film surface. Furthermore, such anodic film revealed some hydrophobic property, which was not observed on the anodic film formed in the base electrolyte without addition of silica sol. And the electrochemical impedance spectroscopy (EIS) results showed that the addition of 10 vol.% silica sol improved the corrosion resistance of the anodic film for the AZ91D Mg alloy obviously.     

丹酚酸A抗肿瘤作用及对逆转A549/MTX肿瘤多药耐药的影响

目的: 探究丹酚酸A的抗肿瘤作用及逆转人肺癌耐药细胞株A549/MTX肿瘤的多药耐药性的作用。方法: 将体外培养人肺癌细胞A549及A549/MTX细胞分别分为3组：空白对照组(只加培养基)、阴性对照组(细胞+培养基)及实验组(细胞悬液+ 3种化疗药)。丹酚酸A以5个浓度(4、8、16、32、64 μg/mL)对A549细胞作用,MTT法检测丹酚酸A在24、48、72 h对A549细胞的抑制作用;同时,检测甲氨喋呤(MTX)、顺铂(CDDP)、吉非替尼(GEF)这3种化疗药对A549、A549/MTX细胞株及丹酚酸A干预后的A549/MTX细胞株的半数抑制浓度(IC50) ,观察丹酚酸A对耐药细胞株的药敏性及药物逆转的作用。结果: 丹酚酸对A549细胞24 h抑制率从(9.16±3.64) %(4 μg/mL)上升至(52.93±5.21)% (64 μg/mL),当浓度增加至64 μg/mL,并分别作用24 h、48 h、72 h后,抑制率为(54.93±5.21)%、(63.83±2.74)%、(72.91±4.06)%,丹酚酸A对A549细胞具有显著的增殖抑制作用,并呈现时间-剂量依赖性。4 μg/mL丹酚酸A对A549细胞及A549/MTX细胞的生长抑制率均低于10%(9.16%,7.38%),说明对两者没有明显的毒性。经4 μg/mL丹酚酸A干预A549/MTX细胞后,甲氨喋呤对A549/MTX细胞株的IC50由(105.72±4.62) μg/mL降低至(26.13±1.36) μg/mL,逆转倍数为4.05倍;顺铂对A549/MTX细胞株的IC50由(174.92±6.86) μg/mL下降至(49.89±1.73) μg/mL,逆转倍数为3.51倍;吉非替尼对A549/MTX细胞株的IC50由(251.38±8.64) μg/mL降为(116.93±5.22) μg/mL,逆转倍数为2.15倍。与对A549细胞的作用相比较,MTX、CDDP、GEF对A549/MTX细胞作用差异均有统计学意义(P<0.01) 。经丹酚酸A干预后,三种化疗药物对A549/MTX细胞作用差异均有显著统计学意义(P<0.01)。结论:丹酚酸A能够抑制A549细胞及A549/MTX细胞的生长,此外,丹酚酸A在体外能够部分逆转A549/MTX的多药耐药性。     

长链非编码RNA FOXN3-AS2在肝癌中的表达及其对肝癌细胞增殖和侵袭的影响

目的: 观察FOXN3-AS2基因在肝癌组织和细胞中的表达,探讨其对肝癌细胞增殖和侵袭的影响。方法: 实时荧光定量PCR（qRT-PCR）法检测肝癌组织和细胞株中FOXN3-AS2的表达水平。在表达水平最低的肝癌细胞株转染携带FOXN3-AS2的质粒以升高FOXN3-AS2的表达,细胞计数试剂盒(cell counting kit-8,CCK-8)和Transwell侵袭实验检测FOXN3-AS2高表达对肝癌细胞增殖活性和侵袭能力的影响。生物信息学预测FOXN3-AS2互补结合的miRNA及相关基因,qRT-PCR检测miRNA和相关基因mRNA的表达水平,Western blot检测相关蛋白的表达水平。结果: FOXN3-AS2在肝癌组织的表达水平显著低于癌旁组织（P<0.01）,在肝癌细胞株的表达水平显著低于人正常肝细胞（P<0.05）,在HepG2细胞的表达水平最低（P<0.01）。FOXN3-AS2高表达可显著抑制肝癌细胞的增殖活性（P<0.05）和侵袭能力（P<0.05）。FOXN3-AS2可互补结合miR-34a-5p,miR-34a-5p可互补结合Kruppel样因子4（KLF4）基因。FOXN3-AS2高表达可降低miR-34a-5p的表达水平（P<0.01）,KLF4 mRNA表达水平升高（P<0.01）,KLF4、β-catenin和E-cadherin蛋白表达升高,CDK4和Cyclin D1蛋白表达降低。结论: FOXN3-AS2在肝癌组织和细胞中表达降低,FOXN3-AS2高表达可抑制肝癌HepG2细胞的增殖和侵袭,其机制可能是调控miR-34a-5p及KLF4基因的表达。     

烧结对羟基磷灰石微球微观结构和性能的影响

利用扫描电镜（SEM）、激光粒度分析仪（LDPSA）、X射线衍射仪（XRD）以及比表面积分析仪（SSA）等检测方法，研究了烧结对于羟基磷灰石微球的微观结构、形貌以及粒径、比表面积和孔隙率等性能的影响。结果表明，经800℃热处理，微球的比表面积、孔隙率及其表面形貌均会发生明显的变化；经1000℃烧结后，部分羟基磷灰石相发生热分解，生成较多的的     

Preparation and application of hydroxyapatite(HA) nanoparticles/NR2B-siRNA complex

Hydroxyapatite(HA) nanoparticles were prepared by coprecipitation-hydrothermal synthesis and their exosyndrome was estimated via transmission electron microscopy. Agarose gel electrophoresis and ultraviolet spectrophotometry were used to evaluate the ability of HA to bind NR2B-siRNA at different pH values and at different HA-NR2B-siRNA ratios. And the stability of the complex in saline was also evaluated. The effect of HA/NR2B-siRNA complex on chronic inflammatory pain was evaluated in vivo in mice. Transmission electron microscopy(TEM) reveals that HA nanoparticles are thin strips or short rod in shape and the one-dimensional particle size of HA nanoparticles is 40-50 nm. Under the acid or neutral condition, the Zeta potential of HA is positive; nanoparticles can completely bind NR2B-siRNA when the HA:NR2B-siRNA ratio is at or larger than 35-1; while under the alkaline condition, the affinity of HA to NR2B-siRNA is rather weak. HA/NR2B-siRNA complex is not dissociated when being resuspended in saline. The nociception of the tonic phase induced by formalin is significantly reduced in the HA/NR2B-siRNA treated mice as compared with the controls. Therefore, HA may be a new siRNA nano-vector material.