製備奈米級複合性高分子雙藥搭載系統於光動力─化學治療之應用

Fabrication of chitosan-based nanoparticles as a dual-functional drug carrier in combinational chemo-photodynamic therapy

張祐誠(Chang, Yu Cheng)

指導教授 ： 黃郁棻

國立清華大學/原子科學院/生醫工程與環境科學系/碩士(2015年)

https://doi.org/10.6843/NTHU.2015.00280

摘要

同時載附雙藥物的奈米級載體在癌症治療領域中為一個較近期的治療方案，由於不同藥物間本身相異的作用機制，在進行治療時期望能夠同時發揮各自的毒理機制，進而達到加成性甚至具有增效作用的效果。本研究主要著重於光動力結合化學性治療。光敏劑選擇玫瑰紅 (Rose Bengal) ，其具有良好的光敏化效率，本身因具有帶負電性的官能基，能夠和帶正電的高分子有著良好的靜電作用力；另一方面，紫杉醇 (Paclitaxel) 做為傳統的化學治療藥物的方案。本研究主要利用甲殼素 (Chitosan) 、聚乙烯醇 (Polyvinyl alcohol)、混合短鏈聚乙烯亞胺 (Polyethylenimine) 等高分子，利用油水乳化法將疏水性的紫杉醇及親水性的玫瑰紅同時包覆，聚乙烯亞胺之陽離子聚電解質特性，可藉由靜電吸引力，進一步提升於中性環境下對於玫瑰紅的裝載效率。搭配牛血清白蛋白本身具有聚兩性電解質的特性，於載體中做為非共價型交聯劑，可以使載體成分間原本藉由靜電作用力所牽引的特性獲得更進一步的提升，使整體結構更為緻密。最後利用電性相異的特性使透明質酸 (Hyaluronic acid)在高分子載體上進行表面吸附的動作，除了有效降低載體原本過高的表面正電性外，更可以做為標靶治療的潛力。最後利用雷射光激發，誘導載體內雙藥物同時引發光動力以及化學藥物的毒性產生，治療效果勝於裝載單一藥物之外，同時在未照光時，能確保能有效包覆藥物以降低藥物本身毒性造成健康細胞的影響。
綜合上述，本研究提出簡單而快速的方式，無須經過化學性修飾或高分子聚合等複雜的製程，只利用數種高分子及藥物的參雜，即能有效的利用靜電作用力達成裝載藥物的目的。透過一系列的細胞實驗測試，首先證實載體具標靶的潛力，相對於大部分載體利用被動標靶的傳遞方式，能夠更有效的利用細胞表面受體的胞吞途徑達到進一步的藥物累積；另外細胞毒性及自由基效率測試，除了呈現出雙藥物結合下的治療優勢外，相對於傳統的光動力治療，提供了一個顯著改善的方案。

關鍵字

高分子藥物載體 ； 光動力治療 ； 結合性治療

並列摘要

Dual functional drug carrier has been a modern strategy in cancer therapy, because it is a platform to evaluate synergistic effect through combination therapy. In the present study, we combined properties of two drugs Paclitaxel (PTX) and Rose Bengal (RB) as a synergistic treatment of chemo-photodynamic therapy . In order to encapsulate these hydrophobic and hydrophilic drugs in one functional system, we fabricate polymeric nanocarriers (NCs) using tripolymer mixtures of chitosan (CTS), branched polyethylenimine (bPEI) and polyvinyl alcohol (PVA) through an oil-in-water emulsion method. The polycationic properties of CTS and bPEI permit effective entrapment of RB molecules. During assembly process, bovine serum albumin (BSA) was also added to condense cationic tripolymer mixtures into stable nanocarriers (BNCs). Eventually, hyaluronic acid (HA) was used as an ionic cross-linking agent through electrostatic interaction to lower down carrier’s zeta potential for suitable application in biological systems. Our results suggest an effective drug loading and high dispersion stability of HBNCs in different buffer solutions. Low leakage of drug molecules from the engineered HBNCs were also confirmed on the basis of dialysis experiments. Moreover, fluorescence microscopic images displayed a high intracellular uptake and localization of drug-loaded HBNCs toward Tramp-C1 cells. The photodynamic effect showed intracellular RB release after photo irradiation; its ROS generation was further evaluated by flow cytometry and alamar blue cytotoxicity assays. Together, our dual-drug carrier system assures enhanced cytotoxicity in cancer cells compared with single-loading drug alone. A dual-functional delivery platform was successfully established to improve the therapeutic efficacy in tumor cells.

並列關鍵字

nanocarriers ； photodynamic therapy ； combinational therapy

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