- 學位論文
超順磁氧化鐵奈米粒子SPIO-mPEG-cRGD之合成、特性探 討及其在磁振造影上之應用
Synthesis and Characterization of the Superparamagnetic Iron Oxide Nanoparticles SPIO-mPEG-cRGD for Magnetic Resonance Imaging
摘要
近年來磁振造影(Magnetic Resonance Imaging，MRI)已被發展至應用於人體到細胞及分子的層級，為完全開發MRI技術應用於細胞、分子與功能性影像，能夠標幟活體細胞的目標化、區域化、量化及功能之新一代MRI對比劑與技術是目前迫切需要。本研究設計利用熱裂解方法合成超順磁氧化鐵奈米粒子(superparamagnetic iron oxide nanoparticles，SPIO) ，並以粒徑為12.8 nm之SPIO為核心包覆成為SPIO-mPEG-cRGD以用於體外(in vitro)細胞影像實驗。藉由超導量子干涉儀(SQUID)量測SPIO-mPEG-cRGD，得知其具有超順磁性、無磁滯現象及高飽和磁化率。包覆修飾後的聚乙二醇(mPPDA-silane)可增加其生物相容性及水溶性，而鍵結生物探針cRGD可使SPIO具有目標化至integrin的效果。 長時間量測弛緩率及水合粒徑，由結果發現長時間並不會造成聚集現象，表示SPIO-mPEG-cRGD具有良好的穩定性。細胞以高濃度SPIO-mPEG-cRGD培養，存活率仍達90%，推測若以低劑量打入動物體內不具有毒性。由體外(in vitro)結果顯示，實驗組細胞之細胞膜上表現integrin受器，其訊號顯著下降，而控制組細胞株影像上無明顯變化，表示SPIO-mPEG-cRGD可藉由受器而標的於細胞膜上。
並列摘要
For the recently year, the synthesis of nanoparticles has been intensively pursued not only for their fundamental scientific interest, but also for their many technological applications. The synthesis of uniform-sized nanoparticles is the key technique because the properties of these nanoparticles depend strongly on their dimensions. From the fundamental scientific viewpoint, the synthesis of uniform-sized nanoparticles with controllable sizes is very important to characterize the size-dependent physical properties of nanoparticles. The novel monodisperse iron oxide nanoparticle are synthesized by thermal decomposition. The surface of iron oxide nanoparticles were coated biocompatible polymer and conjugated with bio-probe (SPIO-mPEG-cRGD). From the results, we found that the SPIO-mPEG-cRGD had well-dispersed in different pH value solutions, no hysteresis, high saturation magnetization (279 emu/g), high relaxivity(r2) and low-cytotoxicity for different cell lines. Targeting of SPIO-mPEG-cRGD into targeted cells was observed by in vitro MR imaging study.