肿瘤热疗用磁流体的制备和表征

目的制备和表征肿瘤热疗用磁流体。方法在聚乙二醇6000（PEG-6000）的存在下用化学共沉淀法制备肿瘤热疗用四氧化三铁（Fe3O4）磁流体,用邻二氮菲显色法测定磁流体中铁的含量,通过电子显微镜、X衍射、红外和振动样品磁强计对制备的磁流体进行表征。测定了磁流体在交变磁场作用下的热效应,并将该磁流体用于VX2兔肿瘤的热疗。结果红外图谱和X衍射图谱证明所制备的磁流体样品为Fe3O4;电镜照片显示磁性粒子近乎圆形且分散良好;经X衍射数据计算得磁性粒子的粒径为13.3±3.8nm;样品的饱和磁化强度和剩余磁化强度分别为23.39A/m（1.556emu/g）和0.56A/m（0.02604emu/g）,矫顽力为12Oe;磁流体的特征吸收率为69±10W/g[Fe]。将该磁流体直接注射于VX2兔肝肿瘤部位后,置于交变磁场中进行热疗,测得肿瘤部位温度可达到41-46℃。结论在PEG-6000存在下所制备的Fe3O4磁流体有望用于肿瘤热疗。     

萘磺酸钠修饰的石墨烯基Fe3O4复合材料的制备与载药性能评价

目的:制备采用1-萘磺酸钠修饰的石墨烯基Fe₃O₄复合材料,并对其性能进行评价.方法:用1-萘磺酸钠进行修饰制备石墨烯基Fe₃O₄复合材料Fe₃O₄/GO-NA,同时进行磁性测定,然后包封盐酸多柔比星(DOX),得到Fe₃O₄/GO-NA/DOX,用高效液相色谱法测定DOX的含量,对其高效装载、缓释性、稳定性和细胞毒性进行分析.结果:Fe₃O₄/GO-NA具有超顺磁性,饱和磁化强度为16.5 emu·g^-1,Fe₃O₄/GO-NA/DOX对DOX的载药率为(68.59±1.02)%(n=3),缓释性及稳定性良好,并且基本无生物毒性.结论:Fe₃O₄/GO-NA/DOX制备工艺可行,性能良好,具有广阔的应用前景.     

聚乙二醇-6000/Fe_3O_4磁流体的制备及性质研究

目的:制备聚乙二醇(PEG)-6000/Fe3O4磁流体并表征其性质。方法:采用化学共沉淀法制备PEG-6000/Fe3O4磁流体,并用透射电子显微镜、激光粒度测定仪、振动样品磁强计、红外分光光度计等来表征磁流体纳米粒的性质。结果:制得的Fe3O4磁流体表面成功包裹了PEG;平均粒径为(10±6)nm;饱和磁化强度为76.22emu·g-1,顺磁性良好;24h的沉降率为16.8%;纳米粒中铁的含量为69.3%。结论:Fe3O4磁流体经PEG包裹后不但其分散性能得到改善,且磁性保持良好。     

萘磺酸钠修饰的石墨烯基Fe3O4-华法林复合材料的研制

目的：合成新型的萘磺酸钠修饰的石墨烯基Fe₃O₄-华法林复合材料（Fe₃O₄/GO-NA/W）,对其进行质量评价并分析其抗凝血性,以期用于心脏支架抗凝血。方法：采用离心法对Fe₃O₄/GO-NA/W的包封率进行测定;计算生成物的回收率、精密度并评价其稳定性;将Fe₃O₄/GO-NA/W复合材料固定于多巴胺涂覆的316 L不锈钢表面,研究其表面抗凝血性能,用扫描电镜观察样品表面血小板的黏附情况。结果：所制得复合材料的包封率（n=5）为（80.1±1.09）%,平均回收率（n=3）为（100.4±0.44）%,华法林检测浓度线性范围为20~100 μg·mL^-1（r=0.999 8）,DA-GNW表面水接触角为（50.8±1.1）°,固定了Fe₃O₄/GO-NA/W复合材料的不锈钢表面具有良好的抗凝效果。结论：Fe₃O₄/GO-NA/W复合材料制备工艺可行,质量控制方法简便可靠,抗凝血性能良好。氧化石墨烯复合材料在心血管材料表面的应用为其生物功能化提供了一种可行的方法。     

荷瘤小鼠体内光敏胶束制剂的分布研究

目的：考察C₆₀/Fe₃O₄-UCNPs@DTX@SNSC在荷瘤小鼠体内的分布特征。方法：采用高效液相色谱法,记录色谱图,计算C₆₀/Fe₃O₄-UCNPs@DTX@SNSC在体内的血药浓度和组织浓度。结果：C₆₀/Fe₃O₄-UCNPs@DTX@SNSC在肿瘤组织中的药物浓度相对较大。结论：制备的C₆₀/Fe₃O₄-UCNPs@DTX@SNSC能够能够显著延长药物在体内的半衰期,增强其抗肿瘤效果。     

TiO2纳米管表面聚合物辅助沉积Ta2O5涂层对MC3T3-E1细胞生物学活性的影响

目的 探讨TiO₂纳米管表面聚合物辅助沉积五氧化二钽(Ta₂O₅)涂层对小鼠成骨前体细胞MC3T3-E1生物学活性的影响。方法 制备出Ta/TiO₂纳米管(Ta/NT组)、Ta₂O₅/纯钛(Ta₂O₅/PT组)及Ta₂O₅/TiO₂纳米管(Ta₂O₅/NT组)3组样本，其中后2组的Ta₂O₅涂层通过聚合物辅助沉积法制备。对3组样品进行表征检测：扫描电镜(SEM)观察表面形貌，X射线光电子能谱(XPS)分析表面元素组成，X射线衍射(XRD)检测表面化合物。选用MC3T3-E1细胞探讨3组样品对细胞生物学活性影响；荧光显微镜观察细胞骨架和细胞核的黏附；CCK-8法测定细胞活性；检测细胞碱性磷酸酶(ALP)活性；茜素红染色后半定量分析钙沉积；Real-time PCR...     

小球藻磁性碳中空微球作为药物缓释载体的开发和应用研究

目的 探究制备小球藻磁性碳中空微球的最佳条件及其装载诺氟沙星后的最佳控释条件。方法 采用水热碳化法合成了以Fe₃O₄为内核的磁性中空碳微球，并利用傅里叶红外光谱(FTIR)以及全自动比表面积和孔隙分析仪对微球进行表征测试。结果 FTIR结果显示微球的疏水性增加是藻壁纤维素亲水基团，如羧基、氨基均发生不同程度的减少造成的。通过全自动比表面积和孔隙度分析仪检测分析，有磁性碳化微球比表面积为0.596 m²/g，微球孔径为3.054 nm。在对诺氟沙星的缓释研究中发现，在pH=7.0时220℃条件下合成的磁性碳中空微球每毫克可以装载诺氟沙星186.32μg，该磁性碳中空微球可以在pH=8.0的环境下实现最优的诺氟沙星控释，3.6 h的累积释药率可达到31%。结论 磁性碳中空微球在pH=8.0的环境下对药物的缓释作用使诺氟沙星可以在肠道中停留较长时间，对肠道中的致病菌起到应有的灭杀作用，并达到了一定程度的靶向给药目的。     

磁感应加热诱导汉防己甲素释放及对肿瘤相关双孔钾离子通道TASK-3的作用研究

目的：构建体外K_2P 9.1（TASK-3）通道过度表达的非洲爪蟾卵母细胞模型;建立外部和磁感应加热2种加热方法,研究其对载汉防己甲素磁性纳米粒中药物释放行为的影响,进一步研究药物及载药磁性纳米粒对TASK-3通道电流的影响。方法：制备载汉防己甲素的聚乳酸-羟基乙酸共聚物（PLGA）磁性纳米粒,采用RP-HPLC考察外部和磁感应加热2种方法对药物释放的影响。采用双电极电压钳技术研究了汉防己甲素、Fe₃O₄-PLGA纳米粒和Tet-Fe₃O₄-PLGA纳米粒及运用磁感应加热诱导药物释放对卵母细胞表面TASK-3通道电流的影响。结果：药物释放量与速率呈现温度依赖性,汉防己甲素对Xenopus oocytes表面TASK-3通道电流有明显抑制作用并呈现剂量依赖性,未载药的PLGA磁性纳米粒对TASK3通道电流不产生影响,而Tet-Fe₃O₄-PLGA NPs在2种加热体系下均显示出对TASK-3通道明显的抑制作用。结论：Tet-Fe₃O₄-PLGA NPs在磁感应作用下能可控性增加汉防己甲素对TASK3通道电流的阻滞作用,这种应激响应性药物递送系统有望成为基于双孔钾通道K_2P9.1靶向治疗的新方法,并有可能用于其他各种癌症治疗。     

药用水基磁流体的一步法制备及其细胞相容性研究

目的制备药用水基磁流体并评价其细胞相容性。方法利用微乳液制备技术,以一步表面活性剂处理法制备药用水基磁流体,并使用透射电镜和光子相关光谱仪研究其形态和粒径分布;分别采用四甲基偶氮唑盐比色试验、乳酸脱氢酶释放试验测定不同浓度药用水基磁流体对正常人肝细胞株(L-02)的体外细胞相容性;运用红外光谱法、热重法、差示热重法、差示扫描量热法对所制备的单层与双层正癸酸包覆的磁流体固态样品进行表征。结果药用水基磁流体粒径在10nm~20nm之间;其放置1y未见发生相分离及明显的数均粒径变化;其对L-02细胞不具有毒性,细胞相容性好。结论药用水基磁流体可用于磁性靶向给药系统。     

叶酸修饰磁性氧化石墨烯载体的制备、表征及其磁性研究

目的:制备叶酸(FA)修饰磁性氧化石墨烯载体(FA-GO-Fe_3O_4),并对其进行表征和磁性研究。方法:以氧化石墨烯(GO)、六水合三氯化铁、四水合氯化亚铁为原料,采用水热共沉淀法制备磁性氧化石墨烯(GO-Fe_3O_4),再通过酰胺键与FA连接,得到FA-GO-Fe_3O_4,采用扫描电镜、红外光谱仪、X射线衍射(XRD)仪和粒度及Zeta电位分析仪分别对GO、GO-Fe_3O_4和FA-GO-Fe_3O_4进行表征,并测定其Zeta电位,通过外加磁场作用和磁滞回线考察FA-GO-Fe_3O_4的磁性。结果:与GO、GO-Fe_3O_4比较,扫描电镜图和XRD图显示,在FA-GO-Fe_3O_4合成中破坏了GO的结构,且表面有粒子团附着,15°～30°之间有非晶相峰;红外光谱显示,FA-GO-Fe_3O_4在574 cm~(-1)和1 640 cm~(-1)处有吸收峰,分别属于Fe-O和—CONH-的特征吸收。GO、GO-Fe_3O_4和FA-GO-Fe_3O_4的的Zeta电位分别为-24、5.62、-22.7mV,FA-GO-Fe_3O_4在外加磁场作用下有明显磁性,在室温、外加正反磁场条件下饱和磁化强度约为20～25 emu/g。结论:本究所制FA-GO-Fe_3O_4具有超顺磁性,且稳定性强于GO-Fe_3O_4。     

Suspension of Fe(3)O(4) nanoparticles stabilized by chitosan and o-carboxymethylchitosan

In this study, a well-dispersed suspension of superparamagnetic Fe₃O₄ nanoparticles was stabilized by chitosan (CS) and o-carboxymethylchitosan (OCMCS), respectively. The resulting magnetic Fe₃O₄ nanoparticles were characterized by dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscope (TEM), zeta-potential measurement and vibrating sample magnetometry (VSM). TEM results demonstrated a spherical or ellipsoidal morphology with an average diameter of 14–20 nm. The adsorbed layer of CS and OCMCS on the magnetite surface was confirmed by FTIR. XRD illustrated that the resulting magnetic nanoparticles have a spinel structure and lastly VSM results showed the modified magnetic Fe₃O₄ nanoparticles were superparamagnetic. The adsorption mechanism of CS and OCMCS onto the surface of Fe₃O₄ nanoparticles is believed to be the electrostatic and coordination interactions, respectively. The mechanisms of both CS and OCMCS stabilizing the suspension of Fe₃O₄ nanoparticles were supposed electrostatic repulsion. These well-dispersed superparamagnetic Fe₃O₄ nanoparticles stabilized by the biocompatible CS or OCMCS dispersant should have potential applications in biotechnology fields.     

壳聚糖-聚丙烯酸磁性微球的制备

目的研究壳聚糖-聚丙烯酸磁性微球的制备及吸附性能。方法在Fe3O4磁流体与分散剂聚乙二醇存在下,壳聚糖与丙烯酸通过戊二醛进行接枝共聚制得表面具有两性基团(-COOH和-NH2)的磁性壳聚糖-聚丙烯酸微球,探讨了聚乙二醇、磁流体、戊二醛交联时间对其制备的影响。结果 20%聚乙二醇量为20mL,0.2g.mL-1磁流体为20mL,25%戊二醛为4mL、反应交联时间为30min。合成的磁性微球粒径约为200nm;磁性微球的饱和磁化强度约为0.5emu.g-1,磁化率可达2.8×10-4;其对胸腺五肽及鸡卵清蛋白有较好的吸附效果,饱和吸附量分别约460mg·g-1和550mg·g-1。结论制备的壳聚糖-聚丙烯酸磁性微球具有较好的吸附性能及磁化强度。     

An In Vitro Study of the Structure-Activity Relationships of Sulfated Polysaccharide from Brown Algae to its Antioxidant Effect

In this paper, the structure-activity relationships of chemically modified uronic acid polymer fragments from brown algae with regard to their antioxidant effects on H₂O₂-damaged lymphocyte were studied. The results indicated that the most potent antioxidant activity was obtained from the sulfated polysaccharide with ratio of mannuronate blocks (M-blocks) to guluronate blocks (G-blocks) of 3 to 1 and carboxyl residue unesterified. The sulfated G-blocks with esterified carboxyl residue also prevented lymphocyte from injury. However, the sulfated G-blocks bearing unesterified carboxyl residue hardly exerted antioxidant activity. These findings suggested that both M-blocks and esterified carboxyl residue were determinant structures in preventing lymphocyte from being oxidized by H₂O₂, indicating that the existence of M-blocks was more important in scavenging free radicals.     

Liquid chromatographic determination of residual hydrogen peroxide in pharmaceutical excipients using platinum and wired enzyme electrodes

Hydrogen peroxide (H₂O₂) is a chemically reactive reagent that can oxidize and degrade many pharmaceutical compounds under normal conditions. Unfortunately, H₂O₂ is often introduced into pharmaceutical excipients during manufacturing and it may significantly affect the chemical stability of drugs in formulations. Thus, a sensitive analytical method for determination of residual H₂O₂ in excipients is of importance in formulation development and product quality control. A liquid chromatographic system with a dual channel electrochemical detector (LCEC) was equipped with either a platinum electrode or a wired peroxidase electrode for determination of H₂O₂. The excipient (0.1 g) was dissolved in 10 ml of mobile phase and 5 μl of the dissolved solution was directly injected. The chromatographic run time for each sample was 1 min with a detection limit of 10 ng/ml (S/N=5) using the platinum electrode and 1 ng/ml (S/N=5) using the wired enzyme coated electrode, respectively. The peak purity was assured by comparing the peak ratios at different potentials for both the standard and the samples. The H₂O₂ levels in different batches of PVP, PEG, and other surfactants from different manufacturers were determined and the values ranged from 0 to 244 ppm. The LCEC method is exceptionally fast, accurate and convenient for quantitation of low levels of residual H₂O₂ in pharmaceutical formulation excipients.