Preparation, characterization, cytotoxicity and drug release behavior of liposome-enveloped paclitaxel/Fe3O4 nanoparticles

Phospholipid vesicles encapsulating magnetic nanoparticles (liposome complexes) have been prepared for targeting a drug to a specific organ using a magnetic force, as well as for local hyperthermia therapy. Liposome complexes are also an ideal platform for use as contrast agents of magnetic resonance imaging (MRI). We describe the preparation and characterization of liposomes containing magnetite. These liposomes were obtained by thin film hydration method and Fe3O4 nanoparticles were synthesized by coprecipitation method. They were characterized by an electrophoretic light scattering spectrophotometer, the liposome complexes were subsequently coated using chitosan. We have further investigated the ability of the above formulation for drug delivery and MRI applications. We are specifically interested in evaluating our liposome complexes for drug therapy; hence, we selected paclitaxel for the combination study. The amount of paclitaxel was measured at 227 nm using a UV-Vis spectrophotometer. Cytotoxicity of liposome complexes was treated with the various concentrations of paclitaxel in PC3 cell lines. The structure and properties of liposome complexes were analyzed by FT-IR, XRD and VSM. The particle size was analyzed by TEM and DLS.     

Fe3O4/聚苯乙烯磁性微球的合成与表征

用化学共沉淀法合成了Fe3O4纳米微粒,并用双层表面活性剂对其进行表面修饰,得到了以水和乙醇为分散介质的磁流体。在磁流体的存在下,用改进的乳液聚合方法合成了Fe3O4/聚苯乙烯磁性微球。X射线衍射研究表明,Fe3O4纳米微粒的平均粒径约为10 nm;在透射电镜下观察磁性微球的粒径在140 nm左右;并用红外光谱和热失重方法表征了复合微球的化学成分及其所含Fe3O4的百分数。阐述了双层表面活性剂改性的机理,并对聚合过程中单体、磁流体及引发剂的用量的影响进行了讨论。     

Deposition and Magnetic Properties of Fe3O4/Fe/Fe3O4Tri-layer Films

1. IntroductionIron oxides include several crystalline forms:hematite (or-FeZO3), magnetite (Fe3O4), maghemite(7-Felon) and wustite (FeO). They have interesting structural and magnetic properties, and are practically important in magnetic and electronic applications. The strongly ferrimagnetic 7--FeZO3 phaseearned much attention due to their applications asrecording media. The attainment of 7-FeZO3 involves complicated processing[1]. In our previousstudies, high coercivity 7-FeZO3, Fe3…     

磁性聚苯乙烯微球的制备与表征

采用化学共沉淀法制备了Fe3O4纳米颗粒,以PEG-4000为表面活性剂进行表面修饰,制备了分散性良好的纳米Fe3O4磁流体.磁流体存在时,采用分散聚合法,以苯乙烯为单体制备了磁性高分子微球.TEM研究表明,Fe3O4纳米颗粒的平均粒径约为10nm,分散聚合所制备的磁性聚苯乙烯微球的平均粒径约为80nm;VSM研究表明,合成的Fe3O4纳米颗粒及磁性聚苯乙烯微球具有超顺磁性;FT-IR研究表明,Fe3O4纳米颗粒很好地包覆于聚苯乙烯中;XRD结果表明,分散聚合前后,Fe3O4纳米颗粒的晶体结构没有发生变化.     

强磁性纳米Fe3O4/SiO2复合粒子的制备及其性能研究

本文采用液相沉积法制备出了满足免疫磁珠用磁核的粒径和磁性要求的纳米Fe3O4/SiO2复合粒子.考察了不同的制备条件对复合粒子的粒径和磁性能的影响,并借助不同的分析测试手段对复合粒子的性能进行表征.结果表明:该复合粒子的最佳制备条件为正硅酸乙酯(TEOS)的浓度为0.6mol·L-1,Fe3O4/TEOS物质的量的比为5:1,反应温度为50℃,搅拌速度为800rpm;在此实验条件下制得的复合粒子的平均粒径在20nm左右,呈球形且分散较均匀,比饱和磁化强度为60.5emu·g-1.     

载药纳米Fe_3O_4/羧化壳聚糖磁性液体的制备与表征

采用化学共沉法制备Fe3O4磁性微粒,用水溶性较好的羧化壳聚糖及用于治疗基底细胞瘤、光化性骨化病的氨基酮戊酸对Fe3O4磁性微粒进行两层包覆,最终形成载药Fe3O4/羧化壳聚糖磁性液体。采用XRD、TEM和FT-IR对载药纳米Fe3O4/羧化壳聚糖磁性液体复合微球的晶型结构、官能团组成及微粒尺寸和形貌等进行了表征。检测结果说明,制备的载药纳米Fe3O4/羧化壳聚糖磁性液体,其核心组份为晶型较好的Fe3O4磁性纳米微粒,磁性微粒的粒径范围为9~11nm;载药Fe3O4/羧化壳聚糖磁性复合微球成类球状;氨基酮戊酸、羧化壳聚糖和Fe3O4分子间发生了化学键的作用;在外加磁场作用下,观察到载药磁性液体的定向移动,有望实现在肿瘤治疗上的主动靶向给药作用。     

SnO2/Fe3O4磁性光催化微纳米材料的制备与性能研究

以磁性纳米颗粒Fe3O4为核,SnCl4.5H2O、氨水、无水乙醇为原料,采用液相共沉淀法在Fe3O4表面包覆一层SnO2光催化剂。采用X射线衍射仪(XRD)及扫描电镜(SEM)分析了其成分和表面形貌。结果显示:Fe3O4纳米颗粒在实验过程中发生了团聚,尺寸增大;当Fe3O4与SnCl4.5H2O物质的量比为(1∶2)～(1∶4)时,SnO2能被较好地包覆在Fe3O4表面,形成核-壳结构的SnO2/Fe3O4复合光催化材料;600℃热处理能够形成结晶性良好的SnO2晶体,但此时Fe3O4转变为Fe2O3,失去了磁性。     

PAn/Fe3O4网状纳米复合物的合成表征及吸波性能

在十六烷基三甲基溴化胺（CTAB）存在下,采用原位化学氧化聚合法制备了聚苯胺／Fe3O4网状磁性纳米复合材料,通过改变Fe3O4纳米粒子在聚苯胺（PAn）中的含量获得了电磁性能可调的纳米复合物,采用FT—IR、XRD、SEM、TEM、电导和磁性能测试对复合物进行了表征,通过矢量网络分析仪获得了试样在2—18GHz范围的复介电常数和复磁导率,经计算获得微波反射损耗曲线,发现当样品中Fe3O4的含量为15．8wt％时,在9．0GHz处具有最大的反射损耗-17．1dB,损耗起．过-10dB的频宽为1GHz。     

纳米Fe3O4/聚乙烯醇磁性水凝胶的制备及性能

利用化学方法制得了纳米Fe3 O4粒子,然后将其与聚乙烯醇(PVA)的胶态溶液共混,通过冻融法制备了纳米Fe3O4/PVA磁性水凝胶.采用综合热分析仪、拉伸试验机及ppms-9综合物性检测系统对磁性水凝胶进行了表征和测试.结果表明,纳米Fe3O4粒子的加入会降低磁性水凝胶的热稳定性;磁性水凝胶的力学性能和磁学性能随纳米Fe3O4含量及冻融次数的改变而显著变化.     

Capture and release of genomic DNA by PEI modified Fe3O4/Au nanoparticles

Polyethylenimine (PEI) modified Fe₃O₄/Au nanoparticles were synthesized in aqueous solution and characterized by photo correlation spectroscopy (PCS) and vibrating sample magnetometer (VSM). The so-obtained Fe₃O₄/Au-PEI nanoparticles were capable of efficient electrostatic capture of DNA. The maximum amount of genomic DNA captured on 1.0 mg Fe₃O₄/Au-PEI nanoparticles was 90 μg. The DNA release behavior was studied and the DNA recovery from Fe₃O₄/Au-PEI nanoparticles approached 100% under optimal conditions. DNA extraction from mammalian cells using Fe₃O₄/Au-PEI nanoparticles was successfully performed. Up to approximately 43.1 μg of high-purity (OD₂₆₀/OD₂₈₀ ratio = 1.81) genomic DNA was extracted from 10 mg of liver tissue. The results indicated that the prepared Fe₃O₄/Au-PEI nanoparticles could be successfully used for DNA capture and release.     

荧光磁性微球Fe3O4@PMAA-Dy的制备和表征

在亲水性Fe3O4磁流体中,以甲基丙烯酸(MAA)为单体,N,N'-亚甲基双丙烯酰胺(MBA)为交联剂,采用光化学方法在水溶液体系中首先合成磁性聚甲基丙烯酸(PMAA)微球,进而在60℃下PMAA与稀土元素Dy离子反应合成具有荧光特性的磁性微球(FMPMs).运用振动样品磁强计(VSM)检测微球磁性能,光子相关光谱仪(PCS)测出微球平均水合粒径,傅立叶变换红外光谱仪(FTIR)和热重-差热分析(TG-DTA)检测了微球的化学组成,扫描电子显微镜(SEM)观测了微球的表面形貌.结果表明,荧光磁性高分子微球有超顺磁性,呈很好的球形,表面含有丰富的稀土羧酸盐.     

Fe3O4/SiO2/CMCH/CdTe荧光磁性微球的合成与表征

利用St ber法和交联法制备出具有荧光和磁性功能的Fe3O4/SiO2/CMCH/CdTe微球,并对其性能和应用效果进行了分析讨论.首先以正硅酸四乙酯为前躯体,Fe2＋和Fe3＋物质的量的比为1∶2,利用超临界干燥法制备出了Fe3O4/SiO2复合微球;并通过透射电镜对其进行观察,Fe3O4颗粒粒径为10 nm,SiO2层厚度为5 nm;其次羧甲基化的壳聚糖（CMCH）被嫁接在Fe3O4/SiO2表面上;然后利用水热法制备出CdTe荧光颗粒,通过壳聚糖与CdTe之间的静电吸引作用,CdTe被吸附在壳聚糖表面;最后利用戊二醛对壳聚糖的选择性交联作用制备出粒径在200 nm以内,饱和磁化强度为22.16 A.m2/kg,且具有良好荧光性能的Fe3O4/SiO2/CMCH/CdTe微球.荧光光谱分析表明最大发射波长从519 nm红移到528 nm,也证实了荧光颗粒CdTe成功吸附在Fe3O4/SiO2/CMCH表面.在动物实验中,该复合微球也显示出良好的荧光性、磁性及稳定性.     

Fe3O4@C核壳结构纳米粒子结构特性表征及应用

目的采用一步法合成Fe_3O_4@C纳米粒子,分析其核壳结构的形成机理,并研究该纳米材料在磁性防伪油墨方面的应用。方法以FeCl_3·6H_2O为铁源,乙二醇为溶剂,葡萄糖为碳源,尿素为碱源,制备具有核壳结构的Fe_3O_4@C纳米粒子,分别采用X射线衍射、场发射扫描电镜、高分辨透射电镜、红外光谱仪和激光拉曼光谱等对其表面形貌和结构进行表征,并对所制备磁性油墨的粘度、抗摩擦性、细度和磁性进行测定。结果所制备的Fe_3O_4@C纳米材料是以平均粒径18 nm的Fe_3O_4为核,厚度为2 nm的无定形碳为壳层的单分散球形纳米粒子,葡萄糖是核壳结构形成的关键;该材料在室温下具有典型的软磁特性,饱和磁化强度为71.2 A·m~(-2)/kg,矫顽力为10 984.8 A/m,所制磁性油墨的墨层耐磨性参数为81%,印记有磁性,粘度为95 Pa·s,各项性能均符合磁性防伪油墨的要求。     

原位生长法制备Fe3O4/TiO2纳米磁性复合体及其表征

采用原位生长法,以钛氧有机化合物为前驱物低温液相在磁性Fe3O4的表面直接形成纳米TiO2,制得Fe3O4/TiO2纳米磁性复合体,利用XRD、SEM、DLS、XPS和PPMS(磁性材料综合物性测量系统)对样品的结构和性能进行表征,并讨论Ti-O-Fe键的形成机理。结果表明:Fe3O4表面被锐钛型的TiO2包覆,且包覆效果良好。该磁性复合体颗粒分布均匀,平均粒径为59nm,饱和磁化强度为3.2emu/g,矫顽力为21Oe。     

纳米Fe_3O_4/Fe复合磁流变液的流变性

用化学共沉淀法合成了纳米Fe3O4粒子,平均二次粒径为51.2nm,比表面积为109.6m2/g。以合成的纳米Fe3O4粒子与羰基铁粉复合配制了纳米复合磁流变(MR)液,并测定了其流变性。结果显示:纳米复合MR液对温度比较稳定;复合MR液在接近零场的低磁场强度下表现为牛顿流体,随着磁场强度提高转变为非牛顿流体;反复加载或撤除磁场,具有"开/关"特性,响应迅速,施加磁场时的响应时间Δt约为50～100ms,撤退磁场时约为100～150ms。     

The grafting and release behavior of doxorubincin from Fe(3)O(4)@SiO(2) core-shell structure nanoparticles via an acid cleaving amide bond: the potential for magnetic targeting drug delivery

Fe(3)O(4)@SiO(2) core-shell structure nanoparticles were first prepared and characterized by TEM, FTIR, XPS and XRD. Subsequently the widely used anticancer agent doxorubincin (DOX) was successfully grafted to the surface of the core-shell nanoparticles via an amide bond with the aid of a spacer arm we synthesized. The spacer arm met two needs: one end can couple to the core-shell nanoparticles' surface while the other end was the active?-COOH group, which can react with the?-NH(2) group of DOX molecules. The synthesized spacer arm and the conjugation of the drug with nanoparticles through amidation were confirmed by FTIR. The DOX-loading efficiency determined by UV-vis spectrometer was 86.5%. Drug release experiments displayed a pH-dependent behavior that DOX was cleaved from the nanoparticles easily under low pH conditions in the presence of protease and that most of the conjugated doxorubincin were released within the first 12?h. The prepared DOX-grafted Fe(3)O(4)@SiO(2) core-shell structure nanoparticles showed a superparamagnetic property with a saturation magnetization value of 49.3?emu?g(-1), indicating a great potential application in the treatment of cancer using magnetic targeting drug-delivery technology.     

Fe3O4/Ni复合纳米颗粒的制备及其微波吸收特性

采用电爆炸技术,合成了粒径约为70nm 的Ni纳米颗粒,以3-巯基丙基三甲氧基硅烷偶联剂(MPTS)对Ni颗粒进行表面改性,利用共沉淀法对改性Ni颗粒进行包覆得到核-壳结构的复合纳米颗粒。将获得的复合纳米颗粒作为微波吸收剂, 并以不同比例分散到热固性酚醛树脂中,涂刷在200mm×200mm的金属板上,用RAM反射率远场RCS测量法研究了微波吸收特性。研究表明,核-壳结构Fe₃O₄/Ni复合颗粒作为微波吸收剂,在相同质量比条件下,其微波吸收性能明显优于纯Ni纳米颗粒或Fe₃O₄纳米颗粒的情况,并且在Fe₃O₄/Ni核-壳结构复合纳米颗粒中随着镍含量的提高,微波吸收增强,而随着Fe₃O₄含量的增加,微波吸收频段向高频段移动。     

PLLA-PEG-PLLA/Fe_3O_4磁性微球的制备及性能

以聚乙二醇为引发剂,L-丙交酯为单体,开环聚合得到聚乳酸-聚乙二醇三嵌段共聚物(PLLA-PEG-PLLA),采用溶剂挥发法制备了PLLA-PEG-PLLA/Fe_3O_4磁性微球,并通过扫描电镜对其形态进行了表征。利用振动样品磁强计和Tg研究了微球的磁含量和磁性能,结果发现,相同粒径不同磁含量的磁性微球,磁含量越高,升温速率越快,当磁含量为70.57%时,升温速率最快,能达到磁热疗的有效温度42℃。对于磁含量相同,粒径不同的微粒,粒径越小,升温速率越快,粒径约为10μm时升温速率最快。     

Synthesis and properties of Fe/Fe3O4 nanocomposites coated with ZnS

Multifunctional Fe/Fe₃O₄@ZnS nanocomposites were synthesized by hydrothermal method, with Fe/Fe₃O₄ doped Co ion as the magnetic core and ZnS as the luminescent shell. The morphology, structure, luminescent and magnetic properties of the nanocomposites were investigated by XRD, FESEM, photoluminescence PL and VSM. The maximum emission peak and special saturation magnetization Ms of the nanocomposites are at 467 nm and 78.6 emu/g, respectively. For the nanocomposites, it is shown that there are both better magnetic behavior and fluorescence properties.