- 學位論文
合成一pH應答型磁性微胞藥物載體應用於抗發炎之研究
Synthesis of pH response magnetic micelles drug carrier for anti-inflammation study
摘要
粥狀動脈硬化病狀為局部且重複性的發炎反應，而在病灶處之酸鹼值相對於人體平均酸鹼值較低。近幾年研究中針對粥狀動硬化之藥物已開發許多，其中橙皮苷元藥物被證實具有抑制發炎反應。於藥物設計中，微胞載體以控制藥物標定與局部釋放行為首要設計條件。本研究目的將製備具生物相容性之pH及溫度應答型磁性微胞藥物載體，並探討載體之物化特性、生物相容性及藥物釋放能力等試驗。藉由溫度應答化學片段NIPAAm、DMAAm及pH應答片段之UA合成一兩性微胞分子，進而接枝親水性磁性奈米粒子，構成具有磁引導性之PH/溫度應答型藥物微胞載體。之後將橙皮苷元透過薄膜透析以親疏水之特性包埋於微胞內，即獲得微胞藥物之載體。物化分析包括藉由傅立葉轉換光譜儀、核磁共振光譜儀、熱重分析儀及超導量子干涉磁量儀分析其特性；場發射槍穿透式電子顯微鏡及動態光散射儀，觀測其微胞型態及粒徑之變化；臨界微胞濃度之螢光分析測得低臨界微胞濃度為0.0315 wt%，且於不同酸鹼之環境下低臨界溶液溫度分別為pH 6.6：37.76 ℃、pH 7.4：41.70 ℃。經細胞毒性試驗證實在500、1000、2000 g/ml濃度下此微胞皆具良好的生物相容性。磁性藥物微胞於體溫環境(37.76 oC)且較酸情況下，足以驅使微胞內之藥物釋放於環境中。依據上述研究結果，本研究已成功製備出符合人體溫度及酸鹼值且具雙重標定之微胞，除了具生物相容性外，亦有攜藥及釋放藥物之能力，以具有生醫應用之可行性。
並列摘要
Atherosclerosis symptoms are repetitive local inflammation and relative lowering of pH value in the focal area. Recent studies have developed anti-inflammatory drugs for atherosclerosis, however there has never been a breakthrough on the treatment efficacy of these drugs. One of the drug, hesperetin has been demonstrated as an inflammation response suppressor and could be used for atherosclerosis treatment. The drug carrier micelles, not only can be used to control drug delivery, but also to prolong the circulating time of the drug and reduce its side effect. The aim of this study was to investigate the chemical synthesis, biocompatibility and in vitro drug delivery response of pH and temperature responsive magnetic micelles. The pH and temperature magnetic responsive micelles, poly( N-isopropylacryamide- co- N,N-dimethylacrylamide -co- 10 undecanoic acid ) / CM-Dextran Fe3O4, were synthesized to be a dual-targeting of the drug carrier by grafting hydrophilic CM-Dextran Fe3O4 onto poly(NIPAAm-co-DMAAm-co-UA). Then, the anti-inflammation responsive drug, hesperetin, was encapsulated by micelles using membrane dialysis method to obtain Hesperetin-loaded P10DF10. The micelles were characterized by Fourier transform infrared spectroscopy, 1H-NMR, Thermo gravimetric analyzer and Superconducting Quantum Interference Device Magnetometer. The morphology and particle size of micelles was observed by Transmission electron microscopy and Dynamic light scattering. Fluorescence analysis indicated that the micelles had a low critical micelle concentration of 0.0315 wt% in aqueous media. The low critical solution temperature of the micelles is in pH 6.6 at about 37.76 °C and in pH 7.4 at about 41.70 °C. The biocompatibility of micelles in different concentration of 500, 1000 and 2000 g/ml were confirmed by cytotoxicity study. Results showed that there were no significant cell cytotoxicity in setting concentration of micelles. Hesperetin-loaded micelles were stable in normal body pH value and temperature, but could be deformed at below normal body pH value to trigger the release of Hesperetin. Based on these results, the present study has successfully polymerized the P10DF10 micelles that have the ability to carry and release drugs. Dual-targeting anti-inflammatory characteristic of micelles confirmed the magnetic targeting and pH responsivity of hesperitin-loaded micelles. It is believed that the P10DF10 micelles have the feasibility for biomedical applications.