單成分磁性奈米粒子以及立方體鈷鐵氧體@四氧化三鐵核殼結構的合成、分析、細胞測試與應用

Preparations, Characterizations, In vitro Tests and Applications of Single-compositional Magnetic Nanoparticles, Cubic Magnetic CoFe2O4@Fe3O4 Core-shell Nanoparticles

陳柏瑋(Bo-Wei Chen)

指導教授 ： 饒達仁

國立清華大學/工學院/奈米工程與微系統研究所/博士(2021年)

摘要

通過共沉法製備超順磁性氧化鐵奈米顆粒(SPIONs，Fe3O4)後，利用簡易球磨法將葡聚醣分子(分子量分別為10、40、70以及100 kDa)包覆到SPIONs表面，以進行葡聚醣包覆的超順磁性氧化鐵奈米顆粒(DSPIONs)的製備。在透射式電子顯微鏡(TEM)、超導量子干涉裝置磁力測定儀(SQUID)和動態光散射粒徑儀(DLS)的測量下，可知DSPIONs的尺寸微奈米級(<20 nm)，並擁有高飽和磁化強度(55-65 emu g-1)以及超順磁性之特性。藉由X射線繞射儀(XRPD)及三維奈米尺度拉曼光譜(Raman)的使用，可證明奈米粒子由四氧化三鐵與γ態三氧化二鐵所組成。衰減全反射傅立葉變換紅外光譜(ATR-FTIR)和熱分析儀熱重分析(TGA)表徵證明表面的包覆層確定為葡聚醣分子。上述的結果表現出與往年期刊文獻不同的結果，文獻中表示使用分子量越大的高分子做為塗層的SPIONs理應擁有較小的淨飽和磁化量，而在此研究中使用不同分子量的DSPIONs卻擁有相近的數值，可見使用球磨法包覆葡聚醣於SPIONs上產生與過往研究部一樣的結果。在細胞測試方面，3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay與普魯士藍染色法證明DSPIONs對肝癌細胞(SK-HEP1)擁有良好的生物相容性，並可以被SK-HEP1胞吞入內，使之可預期作為一種癌症治療的磁性藥劑載具。球磨後，DSPIONs進一步藉由不同的官能基-氨基(NH2)、羥基(OH)和羧基(COOH)修飾進行改性，以備將來應用。使用各種不同分子量的DSPIONs經各種官能基的修飾後(外接的氨基、羥基及羧基)後，展現出的物理性質(磁化量、粒徑、水和粒徑及表面的葡聚醣包覆量)同樣地不因高分子分子量的不同而有明顯差異。DSPIONs和那些其他團隊之SPIONs樣品相比，具有良好的性能。有望用於的磁振造影(MRI)、磁熱治療(hyperthermia)及藥物輸送(drug delivery)。
　　近年來，利用鐵基磁性奈米粒子的磁流體磁熱治療與標靶化療法的整合被視為具潛力的癌症療法。但是，因為鐵基粒子的磁化曲線過於狹小，粒子的劑量濃度往往需要為極大值，才可達到有效的熱治療效果，然而對動物體的傷害過大，進而生副作用。為了加強磁性粒子的磁性性質以增強其熱治療效果，在適當的磁化曲線範圍內，擴張磁化曲線為較佳的選擇。在此部分研究中，我們合成了球狀以及立方體狀的氧化鐵、鈷鐵氧體粒子以及鈷鐵氧體基核殼結構粒子，藉由建構核殼結構奈米粒子研究其磁晶體異向性和表面異向性(magnetocrystalline and surface anisotropy)對粒子翻轉(relaxation)的影響，藉由粒子結構設計調整Néel and Brownian翻轉參數，以此優化磁熱治療效果。此部分最終將CoFe2O4@Fe3O4核殼磁性奈米粒子包覆上抗癌藥物temozolomide (TMZ) 以及lactoferrin (Lf)，並在外加交變場下(50 kHz, 200 G)進行磁熱測試。細胞實驗使用老鼠星形細胞瘤ALTS1C1細胞系(mouse astrocytoma ALTS1C1 cell line)進行體外及離體測試(in vitro and ex vivo tests)，根據觀察，經外加交變場操作後，細胞周圍出現大量的細胞殘骸，這個狀況顯示，除了磁熱和藥物效果外，極可能在細胞中出現機械扭力(mechanical torques)，導致癌細胞死亡，產生治療效果。這個結果顯示立方體核殼結構有作為磁性藥物的潛力。
　　除了上述的複合式治療法外，透過包含了2種或2種以上不同材料來組合、獲得多種複合性質的片狀結構，廣受多個研究單位注意。部分團隊利用二硫化鎢(WS2)或二硫化鉬(MoS2)奈米薄片(nanosheets)作為硫化物的光電特性配合上磁性奈米顆粒(MNPs)非接觸性和可控性，組合成MNPs decorated WS2多層結構而成為熱門題目。在本研究中，WS2 nanosheets被選為光熱療法(photothermal therapies)的吸收與放熱測試材料，通過吸收808 nm雷射並產生熱量來進行測試。為了合成用於奈米複合結構(nanocomposite)的MNPs，研究中製作了多種MNPs並進行比較，包含球形與立方氧化鐵、鈷鐵氧體和鈷鐵氧體@氧化鐵之核/殼結構奈米顆粒。為了研究性質和可行性，使用TEM、SQUID、ATR-FTIR、XRD和拉曼光譜進行測試。最後，通過進行808 nm雷射測試了用鈷鐵氧體@氧化鐵之核殼奈米粒子修飾的二硫化鎢奈米薄片(WS2/CoFe2O4@Fe3O4)之光熱性質。結果顯示其擁有望作為遠程磁性治療工具的潛力。

關鍵字

超順磁性奈米粒子 ； 磁熱治療 ； 核殼結構磁性粒子 ； 二硫化鎢 ； 金屬有機骨架結構 ； 光熱效率測試

並列摘要

To prepare the dextran-coated superparamagnetic iron oxide nanoparticles (DSPIONs) coated with dextran (molecular mass (Mdextran) of 10, 40, 70 and 100 kDa), a simple ball milling method was implemented in the presence of dextran molecules and superparamagnetic iron oxide nanoparticles (SPIONs) after co-precipitation method. The saturation magnetization (Ms) and surface coating percentage (thermogravimetric analysis) of the DSPIONs with various Mdextran were similar to each other and independent on Mdextran. The results were different from the statistical data from previous studies: DSPIONs using increasing Mdextran were accompanied by decreasing Ms and increasing surface coating in conventional co-precipitation protocols without the implementation of ball milling method. The DSPIONs were characterized with transmission electron microscopy (TEM), superconducting quantum interference device (SQUID) magnetometry, dynamic light scattering (DLS), Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffractometer (XRD), 3D nanometer scale Raman spectroscopy (Raman) and thermogravimetric analysis (TGA) of thermal analyzer to confirm the properties of morphologies, magnetic properties, hydrodynamic diameter in DI water, surface coating and modified functional groups, crystalline structures, phases and weighty percentages of dextran on the SPIONs, respectively. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay indicated the ball-milled DSPIONs exhibited low cytotoxicity in human hepatoma cells (SK-HEP1), and the implementation of Prussian blue staining proved the DSPIONs were able to be uptaken by SK-HEP1. There was no obvious difference between the ball-milled DSPIONs with various Mdextran. According to the results, it demonstrated the ball-milling process might be potential for the SPION preparation in biomedical field. The DSPIONs were further modified with several functional groups – external amino, hydroxyl and carboxyl groups – for the future applications which need to conjugate with antibodies or drugs with specific groups. The modified DSPIONs possess similar physical properties but different surface charges with DSPIONs. Similar to DSPIONs, the modified DSPIONs using various Mdextran performed similar magnetic properties, core size, hydrodynamic diameters and dextran contents in whole particles, independent on Mdextran.
　In recent years, the dual treatment integrating magnetic fluid hyperthermia (MFH) and chemotherapy, using SPIONs, is one of potential tumor therapies. To achieve sufficient MFH efficacy, it is essential to satisfy the thermal efficiency by increasing the concentration of the administrated iron due to their narrow magnetization curves, but an inappropriately large administration concentration causes deterioration of an animal’s health. Expanding the magnetization curve is one strategy to optimize the MFH efficacy. To prove the greater magnetic properties of cubic core-shell MNPs we prepared, there were also several different shaped MNPs produced, including spherical and cubic SPIONs, CoFe2O4 and CoFe2O4 based core-shell nanoparticles. This part describes constructuring core-shell cubes causes the coercivity and magnetization to become significantly enhanced related to magnetic nanoparticles (MNPs) of a single composition, of which the magnetocrystalline and surface anisotropy act as roles for MNP relaxation; Néel and Brownian relaxation can be structurally adjusted for the particles to maximize the treatment efficacy in cooperation with an alternating magnetic field (AFM, 50 kHz, 200 G) system. Furthermore, core-shell CoFe2O4@Fe3O4 (cobalt ferrite core coated with iron oxide shell) cubes coated with temozolomide (TMZ) and lactoferrin (Lf) for the magnetothermal penetration delivery. Their biocompatibility on the mouse astrocytoma ALTS1C1 cell line was tested in in vitro and ex vivo in the absence of an AMF. After an AMF implemented, much cell debris was observed, indicating that mechanical torques contributed from endocytosed MNPs exhibited lethal effects besides magnetothermal and chemotherapeutic effects. The results reveal core-shell cubes have a potential to treat tumors as a magnetic drug.
　Other to the dual integrated treatments using MNPs, nanocomposite nanosheets merit of attention about the combination between 2 or more properties from different materials. The tungsten disulfide (WS2) nanosheets decorated with MNPs become popular topic because of its optoelectronic or photothermal properties of the sulfides and contactless controllability of the MNPs. In this work, WS2 nanosheets were chosen as the potential absorbing and exothermic material for photothermal therapies, by absorbing 808 nm laser and generating the heats to kill the cancer cells. The cubic core-shell MNPs, previously mentioned, were integrated into the applications of WS2 nanosheets. To investigate the properties and feasibility, TEM, SQUID, ATR-FTIR, XRD and Raman spectroscopy were used. Finally, the photothermal properties of WS2 nanosheets decorated with cobalt ferrite@iron oxide core-shell nanoparticles (WS2/CoFe2O4@Fe3O4) were tested by the irradiation of 808 nm laser. The results revealed it could be one of the excellent promising candidates as a remote magnetic treatment.

並列關鍵字

Superparamagnetic iron oxide nanoparticles ； Magnetic fluid hyperthermia ； Core-shell magnetic particles ； Tungsten disulfide ； Magnetic nanocomposite ； Photothermal efficiency test

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