摘要
顺铂是一种临床常用的细胞周期非特异性强效抗癌药，对于多种实体细胞瘤如黑色素瘤、头颈部癌、非小细胞肺癌等都具有抑制细胞活性作用。尽管顺铂在治疗癌症过程中能够起到很好的疗效，但其体内毒性较大，易引起严重的胃肠道反应、肾毒性、耳毒性等毒副反应而影响了临床应用。因此如何使顺铂能够选择性到达肿瘤细胞，降低药物毒性提高治疗效果是现阶段研究的主要方向。
磁性热敏性脂质体是将磁性材料和药物包裹在脂质体内的新型靶向制剂，给药后在身体的局部施加固定磁场以增加其在局部滞留时间提高其靶向性，随后在温热刺激下快速释放药物起到局部杀伤效果，可减少对正常组织的影响，提高药物的治疗效果。
目的：对顺铂磁性脂质体的分子组装方式进行设计，通过选用适合的磷脂前体，设计合理的制备过程，来改善脂质体的载药率，提高其靶向性。此外对二棕榈酰磷脂酰胆碱（DPPC）与多种金属离子的相互作用进行研究，探讨金属离子辅助载药的模式和机理，为提高脂质体的载药率提供新的途径。
方法：
采用改良水热合成方法一步制备表面被有机基团修饰的Fe3O4磁性纳米颗粒，对磁性颗粒进行XRD、TEM、IR表征。以天然蛋黄卵磷脂（EPC）为原料，采用石墨炉原子吸收分光光度法测定顺铂含量，以包封率为指标讨论磁性脂质体不同制备方法。利用薄膜分散法对影响磁性脂质体包封率的处方因素进行正交实验，确定脂质体最佳制备和处方工艺。
利用EPC为磷脂材料，在筛选出来的最佳制备条件下，以顺铂抗癌药物为模型药物，探讨薄膜分散法制备脂质体过程中磁性颗粒不同的加入顺序对脂质体微观结构的影响，即程序I：将磁性颗粒先与磷脂结合再成膜制备脂质体；程序II：将磁性颗粒分散于药物溶液中水合制备脂质体。通过透射电镜对脂质体微观结构进行观察，寻找适合的纳米磁性脂质体的组装方式并对其进行体外释放实验。
以DPPC为原料，分别利用两种程序制备顺铂磁性热敏性脂质体，从分子水平探讨单一组分的磷脂前体对合成的脂质体理化性质的影响，并对脂质体稳定性及药物体外释放进行质量评价。通过动物实验对磁性脂质体的磁靶向性进行研究考察。利用差热分析、红外光谱和拉曼光谱对4种金属离子（Zn~(2+)，Cu~(2+)，Mn~(2+)，Mg~(2+)）与DPPC的相互作用机理进行分析，并制备金属离子辅助载药的脂质体，探讨其提高载药率的机理。
结果：
改良水热法制备Fe3O4磁性纳米颗粒的方法不需要高温和氮气保护，生成的粒子粒径为8.9nm，具有超顺磁性，且表面被有机基团所修饰可提高其亲油性，增加与磷脂的结合能力。
选用葡聚糖Sephadex G-50凝胶柱对磁性脂质体与游离药物进行分离。确定采用薄膜分散法制备顺铂磁性脂质体，经正交实验设计筛选了制备磁性脂质的最优处方为EPC浓度=100mg·mL~（-1）；EPC：CH=7：1(w/w)；EPC：Fe3O4=5：1(w/w)；顺铂浓度=1mg·mL~（-1）。
利用EPC为磷脂材料考察两种不同制备程序对脂质体微观结构的影响，透射电镜观察发现，程序I制备的脂质体磁性颗粒分布于磷脂双层中，而程序II制备的脂质体磁性颗粒分布于脂质体中间水相。采用程序I制备的磁性脂质体在药物包封率和磁性颗粒的含量上都优于程序II，药物包封率分别为34.90±3.31%和28.34±4.72%，磁性颗粒的包封率分别为4.19±1.70和3.05±3.13mg·mL~（-1），同时磁性脂质体药物包封率均高于普通脂质体。上述3种不同脂质体体外释药均符合一级释药规律，能保证一定的缓释效应。
DPPC作为热敏性磷脂材料，为保证脂质体的热敏性确定了以DPPC：CH为7：1制备脂质体。程序I制备的磁性脂质体同样使磁性颗粒均匀分散在磷脂双层中，并且磁性颗粒和药物的装载量均较高分别为33.51±3.30%和2.34±0.09mg·mL~（-1）。与EPC相比，DPPC制备的磁性脂质体囊泡粒径较小，且均匀性和磁性颗粒在磷脂层中的分散性更好。DSC与体外热敏释放共同证明了顺铂磁性热敏性脂质体具有良好的热敏性，并且通过动物实验证明了其在体内具有明显的磁靶向，可以有效运载顺铂至靶部位。
由于金属离子与DPPC的磷脂酰基团产生静电力作用改变了DPPC的构象，导致了脂质分子碳氢链排列更紧密，从而使Tm升高，并且随着金属离子原子序数的增加，半径减小，阳离子单位体积的电荷密度增加，金属离子与DPPC分子间的静电作用加强。金属离子辅助载药脂质体的药物包封率均明显高于普通脂质体，并且仍能保持着良好的热敏释药性。
结论：以改良水热法制备的Fe3O4磁性纳米颗粒为磁性材料，通过先将磁性颗粒与磷脂相结合的方法制得到磁性颗粒能均匀分散在磷脂双层中，且磁性颗粒和药物的装载量均较高的磁性脂质体。同时利用热敏磷脂材料制备了具有热和磁双重靶向效果的磁性热敏性脂质体，在体内、外能保证良好的磁性靶向性。本论文中磁性脂质体的研究为靶向给药系统的研究提供了有力的借鉴。此外通过研究金属离子与DPPC相互作用为进一步探讨金属离子辅助载药的新模式奠定了一定理论基础。
Cisplatin, a potent cell cycle nonspecific antineoplastic drug, is widelyused against various solid tumors, such as melanomas, head and neck tumors,endometrial cancer cell, as well as non-small cell lung cancer. Althoughtreatment with this drug is often effective, its therapeutic exploitation islimited by its severe toxicities, including nephrotoxicity, ototoxicity, as well asother side effects such as nausea and vomiting. Therefore, the significantresearches of cisplatin are selecting delivery to tumour cells, reducing drugtoxicity, and improving the therapeutic index.
Thermosensitive magnetoliposomes, used as a targeted drug deliverysystem, trap magnetic nanoparticles (MNs) and drug in liposomes. Liposomestrapped with MNs allow the liposomes to be concentrated in a desired area inthe organ of a patient by magnetic force; meanwhile, the drugs could display arapid release under the local hyperthermia. Compared with ordinary liposomes,thermosensitive magnetoliposomes can play a partial destruction effects,reduce the impact of normal tissues, and improve the therapeutic effect.
Objective: Assembly of cisplatin magnetic liposomes was designedusing a suitable phospholipid precursor, and a reasonable preparation processwhich could improve the drug encapsulation efficiency and targeting ofliposomes. Furthermore, the interaction of dipalmitoyl phosphatidylcholine(DPPC) with a variety of metal ions and the mechanism of the metalion-assisted cisplatin loading model were investigated, which could provide anew approach to improve drug loading efficiency.
Methods:
The Fe3O4MNs coating by organic functional group on surface weresynthesized by a one-step modified hydrothermal method, then, weresubjected to XRD, TEM, IR characterizations. Using egg lecithin (EPC) as phospholipid material, the magnetic liposomes were prepared by differentmethods. Using selected film dispersion method, the optimized prescription ofmagnetic liposomes was selected by orthogonal test in which encapsulationefficiency of cisplatin was used as index and graphite furnace atomicabsorption spectrophotometry (AAS) was used to determine cisplatin.
Based on EPC phospholipid material, and film dispersion method,magnetic liposomes with different microstructure were prepared by the twodifferent procedures. In procedure I, MNs were combined with phospholipidsduring film formation, and in procedure II, MNs were mixed with drugsduring hydration. The microstructures of liposomes were observed bytransmission electron microscope (TEM) to seek for a reasonable assembly ofmagnetic liposomes. The release of cisplatin from liposomes was evaluated invitro system.
DPPC based cisplatin thermosensitive magneticliposomes were preparedusing two different procedures. From the molecular level point of view, theinfluence of the single component phospholipid precursor on physiochemicalproperties of liposomes was investigated. The stability and drug releasecharacter of DPPC-based liposomes in vitro were evaluated, and the magnetictargeting was investigated by animal experiments. The interactions betweenfour kinds of metal ions (Zn~(2+), Cu~(2+), Mn~(2+), Mg~(2+)) and DPPC were analyzed bydifferential thermal analysis (DSC), infrared spectroscopy (IR) and Ramanspectra. Liposomes prepared using metal ions-assisted loading model and themechanism of its higher drug encapsulation efficiency were investigated.
Results:
The Fe3O4MNs were synthesized by a one-step modified solvothemalmethod at low temperatures and short times in a N2-free environment. Themean particle size of superparamagnetic MNs is8.9nm. The oleicacid-coating MNs could change their surface properties, improve thelipophilic character, and increase their combination ability with phospholipids.
Liposomes were synthesized by film dispersion method and theencapsulation was determined using sephadex G-50column as separating instrument. The optimized prescription of magnetic liposomes was:100mg·mL~（-1） of phospholipids,1mg·mL~（-1） of cisplatin, EPC:CH=7:1(w/w) andEPC: Fe3O4=5:1(w/w).
The microstructures of EPC-based magnetic liposomes synthesized bythe two different procedures were observed by TEM. In procedure I, MNswere embedded in a phospholipid bilayer. In procedure II, MNs werecontained in an interior aqueous compartment. MNs-loaded liposome byprocedure I was superior over procedure II both in cisplatin encapsulationefficiency and MN content; the encapsulation efficiency of cisplain inprocedure I and II liposomes were34.90±3.31%and28.34±4.72%,respectively, while, MN content in procedure I and II liposomes were4.19±1.70and3.05±3.13mg·mL~（-1）respectively. Encapsulation efficiency ofcisplain in both I and II magnetic liposome were higher than MNs-freeliposome. The release profile of all the three different liposomes in vitro fittedwith a first-order equation which would ensure sustained-release character.
When DPPC was used as a heat-sensitive phospholipid material,liposomes showed thermosensitive at the ratio of DPPC/CH lower than7:1.Thermosensitive magnetic liposomes prepared by procedure I also trappedwell-dispersed MNs in the bilayer; the encapsulation efficiency of cisplain andthe content of MN were33.51±3.30%and2.34±0.09mg·mL~（-1）, respectively.Compared with EPC-based magnetic liposomes, the mean size of liposomevesicles was smaller, and vesicles uniformity and magnetic particles dispersityin the phospholipid layer are better. Furthermore, as-prepared thermosensitivemagnetic liposomes showed fine heat sensitivity proved by DSC and in vitrothermal release experiment, meanwhile, showed the magnetic targeting in vivowhich can delivery cisplatin to the target location proved by animalexperiments.
The electrostatic interation between the metal ions and phospholipid acylgroup of DPPC resulted in the change of DPPC conformation and thehydrocarbon chain of lipid molecules arranged closer than before. The TmofDPPC is increased. Followed the increasing atomic number and decreasing radius of metal ions, the charge density of cations increase, and theelectrostatic interaction between metal ions and DPPC strengthen. Theencapsulation efficiency of the metal ion-assisted loading liposomes wassignificantly higher than metal ion-free liposomes, and still maintained goodthermal release.
Conclusion: The Fe3O4MNs synthesized by a one-step modifiedhydrothermal method were used to prepare magnetic liposomes. The magneticliposomes were prepared by procedure I in which combined with MNs andphospholipids during film formation. MNs were embedded in a phospholipidbilayer and the encapsulation efficiency of cisplain and the content of MNwere higher than those of conventional liposome. Thermosensitive magneticliposomes prepared by thermosensitive phospholipid material showed the dualeffect both of heat sensitivity and targeting. It would ensure sustained-releasecharacter in vitro and vivo. The investigations on magnetic liposomes in thispaper can provide a strong reference for targeted drug delivery system. Inaddition, the research on the interaction between metal ions and DPPC offereda theoretical foundation for further investigations of metal ion-assisted drugloading liposomes.
引文
1Kahani SA, Jafari M. A new method for preparation of magnetite fromiron oxyhydroxide or iron oxide and ferrous salt in aqueous solution.Journal of Magnetism and Magnetic Materials,2009,321(13):1951~1954
2Wen Jiang, Yao Wu, Bin He, et al. Effect of sodium oleate as a buffer onthe synthesis of superparamagnetic magnetite colloids. Journal of Colloidand Interface Science,2010,347(1):1~7
3王秀敏,邓英杰,赵春杰等. β-榄香烯油水分配系数的测定.沈阳药科大学学报,2005,22(4):289~290
4徐文,孙进,张婷婷等. HPLC法测定冬凌草甲素的平衡溶解度和表观油水分配系数.沈阳药科大学学报,2007,24(4):220~222
5吴华,李绍南.石墨炉升温程序的干燥技术.中国环境监,1997,13(3):55~57
6吴华,李绍南.石墨炉升温程序的灰化技术.中国环境监测,1998,14(3):32~34
7吴惠刚,黄诚.石墨炉原子吸收光谱法测定血中铅升温参数探讨.中国卫生检验杂志,2003,13(5):608~609
8Kim DK, Zhang Y, Voit W, et al. Synthesis and characterization ofsurfactant-coated superparamagnetic monodispersed iron oxidenanoparticles. Journal of Magnetism and Magnetic Materials,2001,225(1):30~36
9洪慧,龙晓英,李力任等.葡聚糖微型凝胶柱测定辣椒碱柔性脂质体包封率的条件探讨.广东药学学报,2005,21(2):120~123
10周莉玲,王岩,刘清飞等.青藤碱脂质体包封率的测定.中国中药杂志,2006,31(9):731~734
11Volodkin D, Mohwald H, Voegel JC, et al. Coating of negatively chargedliposomes by polylysine: Drug release study. Journal of ControlledRelease,2007,117(1):111~120
12高晓黎,季兴梅.葡聚糖凝胶柱色谱法测定脂质体包封率的条件筛选.中国药学杂志,2005,21(2):120~123
13胡晓倩,陈来同,陈雅蕙等.凝胶过滤分离蛋白质实验条件的研究.中国生化药物杂志,2007,28(6):409~411
14Gonzales M, Krishnan KM. Synthesis of magnetoliposomes withmonodisperse iron oxide nanocrystal cores for hyperthermia. Journal ofMagnetism and Magnetic Materials,2005,293(1):265~270
15Yokoyama S, Inagaki A, Imura T, Ohkubo T, et al. Membrane properties ofcationic liposomes composed of dipalmitoylphosphatidylcholine anddipalmityldimethylammonium bromide. Colloids and Surfaces B:Biointerfaces,2005,44(4):204~210
16许汉林,孙芸,邵继征等.不同方法制备姜黄素脂质体的研究.中国中医药信息杂志,2006,13(7):51~52
17Zhu L, Huo Z, Wang LL, et al. Targeted delivery of methotrexate toskeletal muscular tissue by thermosensitive magnetoliposomes.International Journal of Pharmaceutics,2009,370(1-2):136~143
18Menager C, Cabuil V. Synthesis of magnetic liposomes. Journal of Colloidand Interface Science,1995,169(1):251~253
19Li J, Qi HY, Shi YP. Applications of titania and zirconia hollow fibers insorptive microextraction of N, N-dimethylacetamide from water sample.Analytica Chimica Acta,2009,651(2):182~187
20Giri J, Thakurta SG, Bellare J, et al. Preparation and characterization ofphospholipid stabilized uniform sized magnetite nanoparticles. Journal ofMagnetism and Magnetic Materials,2005,293(1):62~68
21Si SF, Li CH, Wang X, et al. Magnetic monodisperse Fe3O4nanoparticles.Crystal Growth Design,2005,5(2):391~393
22Kristjansson F, Sternson LA, Lindenbaum S. An investigation on possibleoligomer formation in pharmaceutical formulations of cisplatin.International Journal of Pharmaceutics,1988,41(1-2):61~74
23Tang X, He ZG, Yu YL, et al. A study on the stability of the cisplatinaqueous solution. J Shenyang Pharm Univ (沈阳药科大学学报),2000,11:405~407
1Liu ShL, Zhang LN, Zhou JP, et al. Structure and properties of cellulose/Fe2O3nanocomposite fibers spun via an effective pathway. J Phys ChemC,2008,112(12):4538~4544
2Pan XG, Guan JJ, Yoo JW, et al. Cationic lipid-coated magneticnanoparticles associated with transferrin for gene delivery. InternationalJournal of Pharmaceutics,2008,358(1-2):263~270
3Dandamudi S, Campbell RB. The drug loading, cytotoxicty and tumorvascular targeting characteristics of magnetite in magnetic drug targeting.Biomaterials,2007,28(31):4673~4683
4Chinese Pharmacopoeia: Vol Ⅱ(中国药典:第二部). Beijing: ChemicalIndustry Press,2010,1, Appendix XC
5Ziyad SH, Reggie CH, Maryam T. Protein release kinetics for core-shellhybrid nanoparticles based on the layer-by-layer assembly of alginate andchitosan on liposomes. Biomaterials,2008,29(9):1207~1215
6Fan XS, Zhang DS, Zheng J. Application of magentic liposomes in curingtumor. Foreign Medical Sci (Cancer Sec)(国外医学肿瘤学分册),2003,30(2):147~149
7Katre NV, Asherman J, Schaffer H, et al. Multivesicularliposome(DepoFoam) technology for the sustained delivery of insulin-like growthfactor-I (IGF-I). J Pharm Sci,1998,87(11):1341~1346
8Dandamudi S, Campbell RB. The drug loading, cytotoxicty and tumorvascular targeting characteristics of magnetite in magnetic drug targeting.Biomaterials,2007,28(31):4673~4683
9Wu Y, Zhang FC, Wu C, et al. Pharmacokinetics of epirubicinhydrochloride long-circulating thermosensitive liposomes in rat plasma.Acta Pharm Sin (药学学报),2010,45(3):365~370
10Giri J, Thakurta SG, Bellare J, et al. Preparation and characterization ofphospholipid stabilized uniform sized magnetite nanoparticles. J MagnMagn Mater,2005,293(1):62~68
11Gonzales M, Krishnan KM. Synthesis of magnetoliposomes withmonodisperse iron oxide nanocrystal cores for hyperthermia. J MagnMagn Mater,2005,293(1):265~270
1Chinese Pharmacopoeia: Vol Ⅱ(中国药典：第二部). Beijing: ChemicalIndustry Press,2010,1, Appendix X C
2Shinkai M, Le B, Honda H, et al. Targeting Hyperthermia for Renal CellCarcinoma Using Human MN Antigen-specific Magnetoliposomes. Jpn JCancer Res,2001,92(10):1138~1146
3Neumann MG, Schmitt CC, Iamazaki ET. A fluorescence study of theinteractions between sodium alginate and surfactants. Permissions&Reprints,2003,338:1109~1113
4Przyby o M, Ol yńska A, Han S, et al. A fluorescence method fordetermining transport of charged compounds across lipid bilayer.Biophysical Chemistry,2007,129:120~125
5Coderch L, Fonollosa J, De Pera M, et al. Influence of cholesterol onliposome fluidity by EPR Relationship with percutaneous absorption.Journal of Controlled Release,2000,68(1):85~95
6Costanzo R, Paoli TD, Ihlo JE, et al. ESR study of order and dynamics inlecithin liposomes with high cholesterol content. Spectrochimica Acta PartA: Molecular Spectroscopy,1994,50(2):203~208
7Nagumo A, Sato Y, Suzuki Y. Electron spin resonance studies ofphosphatidylcholine interacted with cholesterol and with hopanoid inliposomal membrane. Chem Pharm Bull,1991,39(11):3071~3074
8Nobuto H, Sugita T, Kubo T, et al. Evaluation of systemic chemotherapywith magnetic liposomal doxorubicin and a dipole external electromagnet.Int J Cancer,2004,109(4):627~635
9Abraham SA, Edwards K, Karlsson G, et al. Formation of transitionmetal-doxorubicin complexes inside liposomes. Biochim Biophys Acta,2002,1565(1):41~54
10Li C, Deng Y. A novel method for the preparation of liposomes: freezedrying of monophase solution. J Pharm Sci,2004,93(6):1403~1414
1袁春波,赵大庆,吴亦洁等.稀土离子配合物与磷脂双分子膜的作用研究.高等学校化学学报,1996,17(1):10~13
2Wang HC. Biological Membrans Structure and Osmosis Regulate,Shanghai: Shanghai Scienceand Technology Press,1987:8
3徐洪文,付素冉,张束空等.金属离子与生物膜脂双层的络合作用研究(I) Eu3+和Al3+对DPPC红外光谱的特性.烟台大学学报,1995(4):39~43
4徐洪文,付素冉,张束空等.金属离子与生物膜脂双层的络合作用研究(II) Eu3+和Al3+对DPPC的核磁共振光谱.烟台大学学报,1996(1):43～48
5Chinese Pharmacopoeia: Vol Ⅱ(中国药典：第二部). Beijing: ChemicalIndustry Press,2010,1, Appendix X C
6Bloch K, Bangham AD, Scherphof GL, et al. Lipids and Mombranes: Past.Presint and Future. Amsterdam: Elsever,1986, pp:336
7Tian Fang, ZengGuangfu, WangDongmei, XiShiquan. FTIR Study onMolecular Mechanism of the Interactions between Rare Earth Ions andDipalmitophosphatidylcholine Cast-dry Film.Chinese Journal of ChemicalPhysics,1995,8(2):134~138
8王玮,李来明,李志丽等.稀土离子与二棕桐酞磷脂酞胆碱脂质体相互作用的分子机制.光谱学与光谱分析,1993,13(5):51~54
9惠歌,赵雨,张巍等.拉曼光谱研究人参皂苷Rb1与DPPC双层膜的作用.光谱学与光谱分析,2010,30(9):2393~2396
10Kisel MA, Kulik LN, Tsybovsky IS, et al. Liposomes withphosphatidylethanol as a carrier for oral delivery of insulin: studies in therat. Int J Pharm,2001,216(1-2):105~114
11Batenjany MM, Boni LT, Guo Y, et al. The effect of cholesterol in aliposomal Muc1vaccine. Biochim Biophys Acta,2001,1514(2):280~290
12Cherney DP, Conboy JC, Harris JM. Optical-trapping Raman microscopydetection of single unilamellar lipid vesicles. Anal Chem2003,75(23):6621~6628
13Zhao B, Li X, Zhao D, et al. Interaction of Scopolamine and Cholesterolwith Sphingomyelin Bilayers by FT-Raman. Spectroscopy Letters,1998,31(8):1825~1837
1Bangham AD, Standish MM, Watkins JC. Diffusion of univalent ionsacross the lamellae of swollen phospholipids. Journal of MolecularBiology,1965,13(1):238~252
2Gregoriadis G, Rymen BE. Liposomes as carriers of enzymes or drugs: anew approach to the treatment of storage diseases. The BiochemicalJournal,1971,124(5):58
3Lee HY, Jung HS, Fujikawa K, et al. New antibody immobilizationmethod via functional liposome layer for specific protein assays.Biosensors and Bioelectronics,2005,21(5):833~838
4Kabalka GW, Davis MA, Moss TH, et al. Gadolinium-labeled liposomescontaining various amphiphilic Gd-DTPA derivatives: targeted MRIcontrast enhancement agents for the liver. Magn Reson Med,1991,19(2):406~415
5Patel HM, Boodle KM, Vaughan-Jones R. Assessment of the potential usesof liposomes for lymphoscintigraphy and lymphatic drug delivery.Biochim Biophys Acta,1984,801:76~86
6Kiwada H, Sato J, Yamada S. Feasibility of magnetic liposomes as atargeting device for drugs. Chem Pharm Bull,1986,34(10):42~53
7Hergt R, Andra W, d'Ambly CG, et al. Physical limits of hyperthermiausing magnetite fine particles. IEEE Trans Magn,1998,34(5):3745~3754
8Nobuto H, Sugita T, Kubo T, et al. Evaluation of systemic chemotherapywith magnetic liposomal doxorubicin and a dipole external electromagnet.Int J Cancer,2004,109(4):627~635
9Abraham SA, Edwards K, Karlsson G, et al. Formation of transitionmetal–doxorubicin complexes inside liposomes. Biochim Biophys Acta,2002,1565(1):41~54
10柳益书,张建新,姚礼庆等.磁性脂质体的研究现状.江苏大学学报医学版,2005,15(1):81~83
11李铁福,邓英杰,王雨青.磁性脂质体的研究进展.药学进展,2002,26(1):5~10
12Babincova M, Sourivong P, Leszynska D. Blood-specific whole-bodyelectromagnetic hyperthermia. Med Hyptoth,2000,55(6):459~460
13McBain SC, Yiu HHP, Dobson J. Magnetic nanoparticles for gene anddrug delivery. Int J Nanomedicine,2008,3(2):169~180
14Chignell CF, Sik RH. Effect of Magnetite Particles on photoinduced andnonphotoinduced free radical processes in human erythrocytes. Photochemand Photobiol,1998,68(4):589~601
15Pakhomov AB, Bao Y, Krishnan KM. Effects of surfactant friction onBrownian magnetic relaxation in nanoparticle ferrofluids. AmericanInstitute of Physics,2005,97(10):305~307
16Tan Y, Zhuang ZhB, Peng Q, et al. Room-temperature soft magnetic ironoxide nanocrystals: synthesis, characterization, and size-dependentmagnetic properties. Chem Mater,2008,20(15):5029~5034
17Xuan ShH, Wang YXJ, Yu JC, et al. Tuning the grain size andparticle sizeof superparamagnetic Fe3O4microparticles. Chem Mater,2009,21(21):5079~5087
18Dandamudi S, Campbell RB. The drug loading, cytotoxicty and tumorvascular targeting characteristics of magnetite in magnetic drug targeting.Biomaterials,2007,28(31):4673~4683
19Pan XG, Guan JJ, Yoo JW, et al. Cationic lipid-coated magneticnanoparticles associated with transferrin for gene delivery. InternationalJournal of Pharmaceutics,2008,358(1-2):263~270
20Skouras A, Mourtas S, Markoutsa E, et al. Magnetoliposomes with highUSPIO entrapping efficiency, stability and magnetic properties.Nanomedicine: Nanotechnology, Biology and Medicine,2011,7(5):572~579
21Zhu L, Huo ZL, Wang LL, et al. Targeted delivery of methotrexate toskeletal muscular tissue by thermosensitive magnetoliposomes.International Journal of Pharmaceutics,2009,370(1-2):136~143
22Elmi MM, Sarbolouki MN. A simple methodfor preparation ofimmuno-magnetic liposomes. Int J Pharm,2001,215(1-2):451~50
23García-Jimeno S, Escribano E, Queralt J, et al. Magnetoliposomesprepared by reverse-phase followed by sequential extrusion:characterization and possibilities in the treatment of inflammation.International Journal of Pharmaceutics,2011,405:181~187
24Nawroth T, Rusp M, May RP. Magnetic liposomes and entrapping:time-resolved neutron scattering TR-SANS and electron microscopy.Physica B,2004,350(1-3): e635~e638
25Menager C, Cabuil V. Synthesis of magnetic liposomes. Journal of Colloidand Interface Science,1995,169(1):251~253
26Shinkai M, Suzuki M, Iijima S, et al. Antibody-conjugatedmagnetoliposomes for targeting cancer cells and their applicat ion inhyperthermia. Biotechnol and Applied Biochemistry,1995,21(2):125~137
27Hodenius M, Cuyper MD, Desender L, et al. Biotinylated Stealthmagnetoliposomes. Chemistry and Physics of Lipids,2002,120(1-2):75~85
28Hiroshi K, Sato J, Yamada S, et al. Feasibility of Magnetic Liposomes as atargeting device for drugs. Chem Pharm Bull,1986,34(10):4253~4258
29Kuznetsov AA, Filippov VI, Alyautdin RN, et al. Application of magneticliposomes for magnetically guided transport of muscle relaxants andanti-cancer photodynamic drugs. Journal of Magnetism and MagneticMaterials,2001,225(1-2):95~100
30Jain S, Mishra V, Singh P. RGD-anchored magnetic liposomes formonocytes/neutrophils-mediated brain targeting. International Journal ofPharmaceutics,2003,261(1-2):43~55
31Viroonchatapan E, Sato H, Ueno M, et al. Magnetic targeting ofthermosensitive magnetoliposomes to mouse livers in an in situ on-lineperfusion system. Life Sciences,1996,58(24):2251~2261
32Dandamudi S, Campbell RB. Development and characterization ofmagnetic cationic liposomes for targeting tumor microvasculature.Biochimica et Biophysica Acta,2007,1768(3):427~438
33Kubo T, Sugita T, Shimose S, et al. Targeted delivery of anticancer drugswith intravenously administered magnetic liposomes inosteosarcoma-bearing hamters. Int J Oncol,2000,17(2):309~315
34Kubo T, Sugita T, Shimose S, et al. Targeted systemic chemot herapy usingmagnetic liposomes with incorporated adriamycin for osteosarcoma inhamsters. Int J Oncol,2001,18(1):121~125
35Shinkai M, Le B, Honda H, et al. Targeting Hyperthermia for Renal CellCarcinoma Using Human MN Antigen-specific Magnetoliposomes. Jpn JCancer Res,2001,92(10):1138~1146
36Ito A, Shinkai M, Honda H, et al. Heat-inducible TNF-alpha gene therapycombined with hyperthermia using magnetic nanoparticles as a noveltumor-targeted therapy. Cancer Gene Therapy,2001,8(9):649~654
37Yanase M, Shinkai M, Honda H, et al. Intracellular hyperthermia forcancer using magnetic cationic liposomes: an in vivo study. CancerScience,1998,89(4):463~469