奈米生物技術影響生物醫學的發展，而近幾年來最受矚目的潛在應用乃是以磷脂質 (phospholipids) 包覆磁性奈米鐵，在外加磁場下，配合熱治療 (hyperthermia) 的方式來抑制癌細胞。而微脂粒 (liposome) 所形成之微胞 (vesicle) 亦具有包覆藥物之機制。因此，此類材料對於癌細胞處理相當具有醫學上的研究價值。
本研究即針對此項材料進行製備與探討。對於磁性奈米顆粒是以共沉澱法進行製備，得到具磁性之奈米氧化鐵 (Fe3O4)，由穿透式電子顯微鏡估算之顆粒粒徑約在 11 nm。再經由磷脂質(1,2-dipalmitoyl-sn-glycero-3-phosphocholine, DPPC) 修飾 Fe3O4，可觀測到分散性良好的磁性奈米氧化鐵，所測得之粒徑均約為 10 nm，且可以利用 X-ray (311) 特性峰計算出奈米氧化鐵和經過 DPPC 修飾的氧化鐵，所得的平均微晶尺寸 (average crystalline size) 各為 18.3 和 17.7 nm。使用熱重損失分析儀 (TGA)、能量散佈儀 (EDS) 可以確定添加之分散劑含量和組成，並經由傅立葉轉換紅外線光譜儀 (FT-IR) 在 2878 和 2984 cm-1 顯示之特徵峰來確定分散劑在磁性鐵表面之情形。利用超導量子干涉儀 (SQUID) 則可以確定磁性奈米粒子和利用 DPPC 修飾的磁性粒子飽和磁化量各為 71.2 和 65.6 emu/g。
對於磁性奈米鐵之包覆是選用薄膜水合法。經由穿透式電子顯微鏡觀察，可以觀測到磷脂質具有包覆修飾過後的Fe3O4。而為了維持微脂粒的穩定性以及黏滯性，故進一步添加特殊官能基在脂質表面上，據文獻指出將聚乙烯二醇 (polyethylene glycol, PEG) 與磷脂醯乙醇胺 (phosphoethanolamine, PE) 結合成酯 (PEG-PE)，會延長微脂粒在血液中之循環時間，並形成立體障礙而避免陷入內皮網狀組織中。於實驗中先將 PEG2000 與 N,N-羰基二咪唑 (N,N'-carbonyldiimidazole, CDI) 進行反應，由 FT-IR 鑑定在 1743 cm-1 有酯類官能基，核磁共振儀 (NMR) 在7-9 ppm 處之化學位移，可推測是咪唑上有三個氫結構；再將 1,2-dimytistoyl-sn-glycerol-3-phosphoethanolamine, DMPE) 與上述步驟形成之產物反應生成 PEG2000-DMPE，經由 FT-IR初步證實在 1735 cm-1 有強的酯類官能基吸收。再以NMR 分析，最主要的 PEG2000 含量是由 PEG 的乙烯質子峰對應膽鹼 (choline) 甲基質子峰的強度比例來估測，與結構是相當符合的。且經過表面修飾的微脂粒，利用 TEM 也可以觀測出其具有包覆磁性奈米鐵的能力。將微脂粒和經過 PEG2000-DMPE 修飾的微脂粒以及包覆磁性材料的微脂粒，利用示差掃描熱分析儀 (DSC) 進行物性探討。

Nano-biotechnonlogy has improved developments of biomedicine. Recently, magnetic liposome has attracted a lot of attentions because of their potential as heating mediator for cancer cell (hyperthermia). Liposome is a hollow vesicle, which can be used as a carrier for medicine entrapment , thus the functions of this material for cancer cell have quite lots of researching value.
In this study, we choose this material to prepare and discuss the structure of magnetic liposome. Magnetic nanoparticles were synthesized by co-precipitation. The size of the Fe3O4 nanoparticles is about 11 nm observed by transmission electron microscopy (TEM). Iron oxide nanoparticles coated with phospholipids (1,2-dipalmitoyl-sn-glycero-3-phosphocholine, DPPC) could be much better dispersed in solution with the average size of 10 nm. And the average crystalline sizes determined by the characteristic peaks of the X-ray diffraction (XRD) at (311) were 18.3 and 17.7 nm. Thermogravimetric analysis (TGA) and energy dispersive spectrometer (EDS) confirmed the amount and ingredient and the characteristic peaks of fourier transform infrared spectro-photometer (FT-IR) spectra also confirm the presence of the surfactant on the magnetite surface, and the FT-IR spectra of the surfactant coated magnetite as well as in the DPPC sample consist of the bands at 2878 and 2984 cm-1. Finally, the results of sperconductor quantum interference device (SQUID) indicated the saturation magnetization of the Fe3O4 and DPPC coated Fe3O4 nanoparticles that are 71.2 and 65.6 emu/g.
The magnetic liposome was prepared by thin film-hydration method. TEM images of magnetic liposome are observed. In order to keep stability and dense of liposome, lipid has been modified with a specific targeting functional group. Some literatures indicate that by the reaction of polyethylene glycol (PEG) and phosphoethanolzmine (PE) to the derivative of ester (PEG-PE), which could prolong the blood circulation time of liposome and avoid the uptake by reticuloendothelial system (RES). In our first protocol step, we mixed PEG2000 and N,N’-carbonyldiimidazole (N,N’-CDI) for ring-opening reaction, then FT-IR can confirm ester functional group at 1743 cm-1, NMR data indicate that the imidazole cyclostructure has three hydrogen atoms with a 7-9 ppm chemical shift. Then mixing 1,2-dimytistoyl-sn-glycerol-3-phosphoethanolamune (DMPE) with the first step product to synthesis PEG2000-DMPE. FT-IR can confirm strong ester functional group at 1735 cm-1. NMR data show the PEG2000 content was estimated from the ratio of the intensity of the PEG2000 ethylene proton peak to that of the choline methyl proton peak. From our experimental results, we can make sure that the preparation is plausible. Besides, by TEM images we have observed that the liposome modified with PEG has tha ability to entrap magnetic nanoparticles.
Finally, differential scanning calorimeter (DSC) was applied to measure physical properties of liposome and modified liposome with or without entrapped magnetic nanoparticles.

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