磁性纳米粒阿霉素微球制备的初探

目的:制备靶向抗癌药物即磁性纳米粒阿霉素白蛋白微球.方法:以阿霉素(ADR)、人血清白蛋白(HSA)和纳米Fe3O4为材料,采用乳化高温固化法制备出磁性纳米粒阿霉素白蛋白微球,并利用Hrtem对其包裹结合性能进行了观察,同时采用HPLC法对其载药量进行测试.结果:有效载药量为2.35%、表观载药量为3.55%.结论:采用乳化高温固化法能制备出磁性纳米粒阿霉素白蛋白微球.     

载阿霉素pH敏感磁性纳米粒的合成及表征

目的 制备具有pH敏感的磁性阿霉素(Doxorubicin,DOX)纳米粒Fe3 O4@nSiO2@mSiO2@PEG-b-PAsp@DOX并进行表征及优化.方法 利用透射电镜、磁滞回线测试仪等对其进行表征,设计正交试验筛选最佳载药条件.结果 载体材料的粒径约为200nm,电位值为-36.5mV,纳米粒的磁饱和强度为8.03emu·g-1,确定纳米粒的最佳合成条件为载体材料10mg,高分子4mg,阿霉素4mg,反应时间为1h,载药量高达(58.50％ ±3.91％),在pH5.2环境下累积释放量较pH7.4高.结论 所制得的Fe3O4@nSiO2@mSiO2@PEG-b-PAsp@DOX载药量高,且具有pH敏感特性及超顺磁性.     

叶酸介导表没食子儿茶素没食子酸白蛋白纳米粒的制备及其体外靶向性与活性评价

研究能主动靶向于前列腺癌细胞PC-3的表没食子儿茶素没食子酸 (EGCG) 白蛋白 (BSA) 纳米粒的制备工艺与体外靶向性和活性评价。去溶剂法制备叶酸介导EGCG白蛋白纳米粒 (FA-EGCG-BSANP), 采用原子力显微镜 (AFM) 观察纳米粒形状和粒径, HPLC测定EGCG的载药量和包封率, 紫外分光光度法测定叶酸偶联量, 以激光共聚焦和荧光分光光度计测定FA-EGCG-BSANP对PC-3细胞的靶向性, 用MTT法测定其体外活性。所得FA-EGCG-BSANP的平均粒径为200 nm左右, 分布均匀; EGCG的包封率可达 (81.5 ± 1.8) %, 载药量为 (29.3 ± 0.6) %, 叶酸偶联量为18.363 μg·mg⁻¹ BSA;PC-3细胞对FA-EGCG-BSANP的摄取量为EGCG-BSANP的23.65倍, 并且呈现较强的浓度依赖性; 同等浓度下FA-EGCG-BSANP对PC-3细胞的抑制率为82.8%, 而EGCG溶液和EGCG-BSANP分别为58.6%和55.1%, 并且抑制率与PC-3细胞对这些纳米粒的摄取能力呈正相关。FA-EGCG-BSANP能明显提高EGCG对PC-3细胞的靶向效果,并提高了对细胞的致死作用,从而提高了EGCG作为一种潜在抗癌药物的治疗效果,为进一步探索该纳米粒在体内的靶向性、活性和代谢规律提供了实验基础。     

载As2O3白蛋白纳米粒对人K562细胞的增殖抑制作用

目的采用白蛋白纳米粒包载As2O3,通过肿瘤细胞摄取载药纳米粒来增强As2O3对K562细胞的增殖抑制作用。方法采用去溶剂化法制备白蛋白纳米粒(ALB-NP),以异硫氰酸(FITC)标记ALB-NP,荧光显微镜观察K562细胞对ALB-NP的摄取;以ALB-NP包载As2O3制备载As2O3白蛋白纳米粒(As2O3-ALB-NP),MTT法比较As2O3与As2O3-ALB-NP对K562细胞增殖抑制率的差异。结果 As2O3-ALB-NP在低浓度(<0.8μmol.L-1)即可显著抑制K562细胞增殖,而As2O3在该浓度对其无抑制作用。结论与As2O3相比,利用ALB-NP载As2O3可显著增强其对K562细胞的增殖抑制作用,有望实现对As2O3用药的增效减毒,为其用于抗肿瘤治疗提供了新的给药策略。     

磁性纳米粒在抗肿瘤药物中的应用

磁性纳米粒是一种新兴的正在迅速发展的新型材料,主要为铁氧体(γ-Fe2O3及Fe3O4)。由于其无毒无害,良好的生物相容性,目前在药物控制释放、肿瘤热疗以及智能开关等多个领域备受关注。本文结合近年来国内外对磁性纳米粒的研究报道,主要介绍了磁性纳米粒的性质及其在肿瘤药物缓控释中的应用等。希望能为其以后的研究和应用提供理论依据。     

PEG-胆固醇双重修饰PBCA纳米粒脑靶向机制

目的中枢神经系统疾病目前存在的主要问题是血脑屏障(BBB)通透性的问题,本实验期望通过制备PEG-胆固醇双重修饰PBCA纳米粒,提高难透过BBB的中枢神经系统疾病的治疗及早期诊断药物的治疗作用,并对其经过BBB进入脑组织的机制进行探讨。方法采用乳化聚合法制备双重修饰PBCA纳米粒并对其理化特性进行评价。(1)双重修饰PBCA纳米粒体内药动学及脑组织分布研究:实验前12小时大鼠进行颈静脉插管手术。实验时于插管处给予原药溶液,胆固醇单修饰及PEG-胆固醇双重修饰PBCA纳米粒。给药后不同时间点取血200μL,化学/发光分析仪测定血液中香豆素-6的含量。大鼠尾静脉分别给予原药溶液、胆固醇单修饰及PEG-胆固醇双重修饰PBCA纳米粒。给药后不同时间点处死大鼠,取脑组织测定香豆素-6的含量。(2)双重修饰PBCA纳米粒体外细胞摄取及转运机制研究:采用b End.3细胞模型(永生化小鼠脑内皮细胞株)评价了载体及纳米粒的体外细胞毒性,同时选用了巨胞饮介导的内吞作用(细胞松弛素D),网格蛋白介导的内吞作用(氯丙嗪),小窝蛋白介导的内吞作用(染料木素),胆固醇耗竭(MβCD和制霉菌素),高尔基体抑制剂(布雷菲德菌素A)和耗能(叠氮钠)等七种细胞摄取抑制剂来研究载药纳米粒的细胞摄取及转运机制。结果 (1)制备的纳米粒粒径为(191.1±1.22)nm、载药量约为1.97%,包封率大于98%。同时双重修饰PBCA纳米粒在体外具有更明显的缓释效果。(2)双重修饰PBCA纳米粒在体内具有更高的血药浓度及缓释效果,能持续释放12 h,而胆固醇单修饰纳米粒仅释放8 h,原药溶液仅4 h内能检测到药物。脑组织分布研究结果表明,双重修饰PBCA纳米粒静脉给药后脑组织中药物含量显著增高且成缓慢释放的过程,说明具有成为脑靶向制剂的研究潜力。(3)载体及载药纳米粒细胞安全性良好,纳米粒在实验范围内没有明显的细胞毒性,具有较好的安全性。选择不同类型的摄取和转运抑制剂研究了载药纳米粒的细胞摄取及转运机制。结果表明,参与细胞转运和摄取的机制可以是不同的,而胆固醇-PEG双修饰PBCA纳米粒在b End.3细胞中的转运机制,是一个包括巨胞饮介导、耗能、同时需要胆固醇参与等多种机制介导的复杂过程。结论本实验制备的PEG20000-胆固醇双重修饰PBCA纳米粒,可解决中枢神经系统疾病的治疗及诊断药物体内BBB通透率低、安全性差、缓释性差等瓶颈问题,具有重要应用前景。     

Fe3O4纳米粒子-氧化石墨烯纳米复合物的制备、表征及体外毒性评价

采用改进的Hummers方法制备氧化石墨烯(GO),再用共沉淀法原位合成Fe3O4磁性纳米粒子修饰的GO复合材料.通过透射电镜(TEM)、傅里叶变换红外光谱(FT-IR)和X-射线衍射(XRD)对Fe3O4纳米粒子-GO复合物的形态进行表征.结果表明,所制复合物中Fe3O4磁性纳米粒子的粒径为30 nm,少量粒子团聚后的粒径为50～100nm.该复合物中GO含有多种官能团,可作为药物连接的位点,还可通过π-π共轭作用与药物连接.在外加磁场作用下,可明显观察到该复合物迅速聚集在永磁体附近.体外细胞毒性试验表明,该复合物在0.5～5 000 μg/ml范围内对肺癌A549细胞和乳腺癌ZR-75-30细胞无细胞毒性.     

基于当归多糖的酶敏肿瘤靶向纳米递药体系的研究

目的构建基于当归多糖(AP)的酶敏肿瘤靶向纳米递药体系:当归多糖-基质金属蛋白酶敏感肽-阿霉素(AP-PP-DOX),研究其理化性质及体外抗肿瘤效果。方法首先将AP用马来酸酐(MA)修饰后得到马来酰化当归多糖(AP-MA),再将APMA和基质金属蛋白酶敏感肽(PP)结合生成当归多糖-基质金属蛋白酶敏感肽(AP-PP),最后将AP-PP和阿霉素(DOX)结合生成当归多糖-基质金属蛋白酶敏感肽-阿霉素(AP-PP-DOX)聚合物。利用FT-IR和1 H-NMR表征各步反应产物;透析法自组装形成纳米粒;粒度分析仪测定纳米粒粒径和电位;TEM观察纳米粒大小及外观形态;紫外分光光度计测定纳米粒载药量;体外模拟释药实验研究纳米粒在MMP-2作用下的酶解释药情况;MTT法研究纳米粒对A549细胞的毒性作用。结果 (1)FT-IR和1 H-NMR表征各步反应产物成功合成;(2)透析法成功制备了AP-PP-DOX纳米粒;(3)测定纳米粒的平均粒径和电位分别是139.00±3.32nm和-28.45±0.22mV;(4)该纳米粒结构圆整,平均粒径为100nm;(5)计算纳米粒载药量为17.00%±1.72%;(6)体外模拟释药结果表明,纳米粒在MMP-2下作用24h累积释药率最高达74.5%;(7)MTT实验表明,当药物质量浓度为9μg·mL-1时,纳米粒对A549细胞的存活率极显著,高于游离DOX(P<0.01),而含有MMP-2的纳米粒对A549细胞存活率极显著,低于不含MMP-2的纳米粒(P<0.01)。结论制备基于AP的酶敏肿瘤靶向纳米递药体系AP-PP-DOX,能够有效实现在MMP-2作用下的酶敏释药及抗肿瘤效果,值得进一步研究。     

甲氨蝶呤叶酸受体-磁双重靶向纳米粒的制备及评价

目的：以甲氨蝶呤为药物模型，制备用于肿瘤靶向治疗的叶酸受体-磁双重靶向纳米药物。方法：未采用 预成型的磁性纳米粒，一步合成磁性纳米粒核二氧化硅壳超顺磁性的纳米粒，并借助透射、扫描电镜观察微球形态，用 硅烷偶联剂进行表面修饰，在表面化学偶联上叶酸，修饰甲氨蝶呤后利用紫外可见分光光度计测量载药量及包封率。结 果：磁性纳米粒在电镜下呈现核壳样球型微粒，平均粒径为20 nm，纳米粒载药量为26.71%，包封率为64.76%。结论： 叶酸受体-磁双重载药纳米粒为肿瘤的靶向治疗提供了一种可能的新剂型，有较好的临床应用前景。     

甲氨蝶呤叶酸受体-磁双重靶向纳米粒的制备及评价

目的：以甲氨蝶呤为药物模型，制备用于肿瘤靶向治疗的叶酸受体-磁双重靶向纳米药物。方法：未采用 预成型的磁性纳米粒，一步合成磁性纳米粒核二氧化硅壳超顺磁性的纳米粒，并借助透射、扫描电镜观察微球形态，用 硅烷偶联剂进行表面修饰，在表面化学偶联上叶酸，修饰甲氨蝶呤后利用紫外可见分光光度计测量载药量及包封率。结 果：磁性纳米粒在电镜下呈现核壳样球型微粒，平均粒径为20 nm，纳米粒载药量为26.71%，包封率为64.76%。结论： 叶酸受体-磁双重载药纳米粒为肿瘤的靶向治疗提供了一种可能的新剂型，有较好的临床应用前景。     

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。     

砷致大鼠海马神经细胞凋亡对学习记忆功能的影响

目的研究长期染砷对大鼠海马细胞超微形态和学习记忆功能的影响。方法 SD大鼠随机分为高、低砷剂量组和对照组,染砷组自由饮用含砷水（高砷组10mg/（kg.d）,低砷组0.4mg/（kg.d））,对照组饮蒸馏水。连续染砷24周后,Morris水迷宫实验评估大鼠学习与记忆能力,单细胞凝胶电泳（SCGE）法检测海马神经细胞DNA损伤情况,透射电镜（TEM）观察海马神经细胞超微结构变化。结果染砷组定位航行试验平均潜伏期比对照组延长（P〈0.05）,空间探索试验在第三象限停留时间百分比均比对照组明显缩短（P〈0.05）。SCGE可见染砷组＂彗星＂拖尾和DNA断裂分级均比对照组明显增加（P〈0.05）,高砷组比低砷组增加更显著（P〈0.05）,有剂量-效应关系。TEM观察可见,对照组海马神经细胞形态和超微结构呈正常表现,低砷组可见核凹陷变形,染色质边集,线粒体肿胀,高砷组还可见线粒体和细胞器减少,胞浆＂空泡＂,部分细胞甚至呈核固缩的细胞凋亡征象。结论慢性染砷可致大鼠海马神经细胞DNA和超微结构损伤,进而引起学习记忆能力障碍。     

羧基化PEG修饰的磁流体的制备和表征(英文)

制备和表征肿瘤热疗用羧基化PEG修饰的Fe₃O₄磁流体。化学共沉淀方法制备四氧化三铁磁性纳米颗粒,然后用羧基化PEG修饰;用邻二氮菲显色法测定磁流体中铁的含量;沉降方法考察了制备的磁流体的稳定性;通过X射线衍射、透射电子显微镜、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。羧基化PEG修饰的磁流体稳定性明显优于未修饰的;红外图谱和X衍射图谱证明所制备的磁流体样品由Fe₃O₄组成;透射电镜照片显示磁性粒子分散良好;经X衍射数据计算得磁性粒子的粒径约为5 nm;羧基化PEG修饰磁流体的饱和磁化强度和剩余磁化强度分别为47.01和3.41 emu/g。矫顽力为6.7 Oe;磁流体的特征吸收率为63.0 W/g[Fe]。羧基化PEG修饰的Fe₃O₄磁流体有望用于肿瘤热疗。     

Berberine‐loaded Janus nanocarriers for magnetic field‐enhanced therapy against hepatocellular carcinoma

Berberine, an bioactive isoquinolin alkaloid from traditional Chinese herbs, is considered to be a promising agent based on its remarkable activity against hepatocellular carcinoma. However, the clinical application of this nature compound had been hampered owing to its properties such as poor aqueous solubility, low gastrointestinal absorption, and reduced bioavailability. Therefore, we developed Janus magnetic mesoporous silica nanoparticles (Fe₃O₄‐mSiO₂ NPs) consisting of a Fe₃O₄ head for magnetic targeting and a mesoporous SiO₂ body for berberine delivery. A pH‐sensitive group was introduced on the surface of mesoporous silica for berberine loading to develop a tumor microenvironment‐responsive nanocarrier, which exhibited uniform morphology, good superparamagnetic properties, high drug‐loading amounts, superior endocytic ability, and low cytotoxicity. Berberine‐loaded Fe₃O₄‐mSiO₂ NPs exerted extraordinarily high specificity for hepatocellular carcinoma cells, which was due to the pH‐responsive berberine release, as well as higher endocytosis capacity in hepatocellular carcinoma cells rather than normal liver cells. More importantly, an external magnetic field could significantly improve antitumor activity of Ber‐loaded Fe₃O₄‐mSiO₂ NPs through enhancing berberine internalization. Taken together, our results suggest that Janus nanocarriers driven by the magnetic field may provide an effective and safe way to facilitate clinical use of berberine against hepatocellular carcinoma.     

Drug-loaded, magnetic, hollow silica nanocomposites for nanomedicine

Magnetic, hollow silica nanocomposites (MHSNC), including nanospheres and nanotubes, have been successfully synthesized using a coating of Fe(3)O(4) magnetic nanoparticles (NPs) ( approximately 10 nm) and silica on nanosized spherical and nanoneedle-like calcium carbonate (CaCO(3)) surfaces under alkaline conditions. The nanosized CaCO(3) surfaces were used as nanotemplates, and tetraethoxysilane and magnetic NPs were used as precursors. The as-synthesized MHSNC were immersed in an acidic solution to remove the CaCO(3), forming magnetic, hollow silica nanospheres and nanotubes. The MHSNC were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray powder diffraction, and superconducting quantum interference device (SQUID) magnetometer. SEM and TEM results showed that a smooth surface of MHSNC and a thin layer of silica ( approximately 10 nm) embedded with the magnetic NPs were successfully formed, and that the CaCO(3) nanotemplates appeared to be dissolved. SQUID measurement demonstrated that magnetization of MHSNC was dependent on temperature, exhibiting superparamagnetism. The MHSNC were immersed in ibuprofen solution. The amount of the loaded drug was determined to be 12 wt% for nanospheres, and 8 wt% for nanotubes by UV measurement, respectively. Drug-loaded MHSNC have potential applications in nanomedicine.     

Restoring basal planes of graphene oxides for highly efficient loading and delivery of β-lapachone

An efficient and biocompatible drug nanocarrier is essential for nanomedicines to realize their full therapeutic potential. Here, we investigate the loading of a selective and potent anticancer drug, β-lapachone (β-lap), on a magnetite nanoparticle-decorated reduced graphene oxide (Fe(3)O(4)/rGO) and the in vitro anticancer efficacy of β-lap loaded Fe(3)O(4)/rGO. Reduced graphene oxide (rGO) with magnetic functionality was prepared via electrostatic interaction between positively charged magnetite (Fe(3)O(4)) nanoparticles and negatively charged GO, followed by hydrazine reduction of GO to rGO. The prepared Fe(3)O(4)/rGO shows that Fe(3)O(4) makes the Fe(3)O(4)/rGO hybrid magnetically separable for easy handling during drug loading and release and the Fe(3)O(4)/rGO hybrid exhibits significantly higher loading capacity than that of Fe(3)O(4)/GO, suggesting that restoration of the graphene basal plane upon reduction of GO enhances the interaction between β-lap and rGO. Cellular uptake studies using fluorescently labeled Fe(3)O(4)/rGO verifies successful internalization of Fe(3)O(4)/rGO into the cytoplasm while rGO without hybridized Fe(3)O(4) has poor uptake performance. Furthermore, β-lap loaded Fe(3)O(4)/rGO shows remarkably high cytotoxicity toward MCF-7 breast cancer cells while the blank Fe(3)O(4)/rGO produces no cytotoxic effects. The cytotoxicity results suggest that Fe(3)O(4)/rGO is an efficient drug carrier for anticancer treatments. The fine-tuning of the chemical structures of graphene oxides by reduction chemistry may provide a universal route for controlled loading and release of drugs or biomolecules to construct advanced delivery vehicles.     

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。     

Thermo-responsive magnetic liposomes for hyperthermia-triggered local drug delivery

We prepared and characterised thermo-responsive magnetic liposomes, which were designed to combine features of magnetic targeting and thermo-responsive control release for hyperthermia-triggered local drug delivery. The particle size and zeta-potential of the thermo-responsive magnetic ammonium bicarbonate (MagABC) liposomes were about 210?nm and ?14?mV, respectively. The MagABC liposomes showed encapsulation efficiencies of about 15% and 82% for magnetic nanoparticles (mean crystallite size 12?nm) and doxorubicin (DOX), respectively. The morphology of the MagABC liposomes was visualised using transmission electron microscope (TEM). The MagABC liposomes showed desired thermo-responsive release. The MagABC liposomes, when physically targeted to tumour cells in culture by a permanent magnetic field yielded a substantial increase in intracellular accumulation of DOX as compared to non-magnetic ammonium bicarbonate (ABC) liposomes. This resulted in a parallel increase in cytotoxicity for DOX loaded MagABC liposomes over DOX loaded ABC liposomes in tumour cells.     

Reversible aberration of neurogenesis affecting late-stage differentiation in the hippocampal dentate gyrus of rat offspring after maternal exposure to manganese chloride

To examine the effects of developmental manganese (Mn)-exposure on hippocampal neurogenesis, pregnant rats were treated with MnCl(2)·4H(2)O in the diet at 32, 160 or 800ppm from gestation day 10 to day 21 after delivery. Serum concentrations of thyroid-related hormones were examined in offspring exposed to MnCl(2)·4H(2)O at 800 or 1600ppm. Immunohistochemical analysis revealed increased doublecortin-positive cells in the subgranular zone of the dentate gyrus on postnatal day (PND) 21 following exposure to MnCl(2)·4H(2)O at 800ppm, indicating an increase of type-3 progenitor or immature granule cells. Reelin-positive cells, suggestive of γ-aminobutyric acid-ergic interneurons in the dentate hilus, also increased at 800ppm on PND 21. Brain Mn concentrations increased in offspring on PND 21 at 160 and 800ppm, whereas brain concentrations in the dams were unchanged. Serum concentrations of triiodothyronine and thyroxine decreased at 800 and 1600ppm, whereas thyroid-stimulating hormone increased only after exposure at 800ppm. All changes disappeared on PND 77. Thus, maternal exposure to MnCl(2)·4H(2)O at 800ppm mildly and reversibly affects neurogenesis targeting late-stage differentiation in the hippocampal dentate gyrus of rat offspring. Direct effects of accumulated Mn in the developing brain might be implicated in the mechanism of the development of aberrations in neurogenesis; however, indirect effects through thyroid hormone fluctuations might be rather minor.