利用連接蛋白質快速組合成標靶奈米粒子以利體外藥物遞送之評估研究

Abstract

奈米科技的研究廣泛在各個領域上，而在生醫領域上，主要有組織再生材料、影像顯影追蹤的顯影劑還有治療癌症疾病的載體。而在治療癌症中，奈米粒子被運用的方式有很多，有物理化療的方式也有將奈米粒子做為藥物的載體。而在做藥物載體的研究時，最大的挑戰就是如何將此載體安全運送到目的地，必須不被身體內的免疫細胞給清除，也不能大部分堆積在肝臟或腎臟，而有效率地送到癌症發生的地方，並且奈米粒子只能專一傳遞給癌細胞，而不能非專一性的遞送，以免造成其他細胞死亡。我們所使用的氧化鐵奈米粒子具有磁性，並且用微脂體包覆藥物在其中，當包覆藥物的奈米粒子在遞送上，可藉由外在磁場引導氧化鐵奈米粒子到作用位置。實驗室所建構的PAST蛋白，是由protein A跟strepavidin所組成的融合蛋白，我們使用中性脂微粒表面修飾biotin，再包覆氧化鐵奈米粒子，製備成磁性奈米脂微粒，biotin可藉由strepavidin與PAST結合，而protein A 可與特定抗體結合，利用此混和好的複合物，即可標定到有特定受體的細胞，就可提高專一性毒殺癌細胞的效果。在本研究中將分析：1. 奈米脂微粒與氧化鐵複合奈米粒子之粒徑分析，； 2. 導向磁性奈米脂微粒專一性標定細胞，利用螢光訊號驗證經由修飾過的複合奈米粒子，是否對特定的細胞具有專一性的遞送； 3. 用包覆藥物的奈米粒子證明，是否有複合式的奈米粒子，可以針對特定的細胞產生細胞毒殺作用。

Liposomes are lipid-based particles and have been reported in clinical applications. Used as drug delivery systems in cancer treatment, a series of strategies have been developed and modified to enhance the therapeutic efficacy of liposomal drugs. The straightforward strategy is designing tumor-specific targeting of liposomal drugs. Therefore we used modified liposomes by specific interaction between ligands and tumor cells for targeting. We constructed an adaptor protein between liposomes and antibodies for cancer cell targeting. Protein A-streptavidin (PAST), a bifunctional fusion protein, could link nanostures of biotinylated liposomes and antibodies together. The cationic liposomes have been used in nanoparticle research recently. We first examined cationic lipid based combination of liposomes for cell targeting. But the big problem is non-specific binding. Since targeted delivery is the major concern in cancer therapeutic studies. Therefore, we changed to another combination of liposomes, using neutral lipids, which can prevent from non-specific binding. The specific targeting strategy can be achieved by linking cellular ligands to the surface of nanoparticles.