利用幾丁聚醣和聚麩胺酸形成的奈米粒子做為Docetaxel載體的製備與特性研究

Preparation and Characterization of Docetaxel-loaded Nanoparticles Composed of Chitosan/Poly-γ-Glutamic Acid

翁晨芳(Chen-Fang Weng)

指導教授 ： 許明照

臺北醫學大學/藥學院/藥學研究所/碩士(2012年)

摘要

傳統癌症治療藥物由於不具專一性，在產生療效同時也造成全身性副作用；且多為難溶性藥物，臨床上所使用之溶劑易造成病患產生過敏反應。因此，本研究利用具有生物降解性之聚合物製備奈米載體以負載難溶性抗癌藥物Docetaxel，來改善以上所述之問題。
奈米粒子廣義定義為10 ~ 1000 nm 大小的粒子，理想的奈米載體比起單純的抗癌藥物可以更專一的遞放藥物、在有效治療範圍內降低藥物毒性，並擁有高安全性及良好的生物降解性。因此，在製備奈米粒子主要考慮材料的生物相容及降解性、藥物的包覆及釋出、奈米粒子的安定性、標的性等。
本研究所使用的材料為幾丁聚醣及聚麩胺酸。幾丁聚醣 (Chitosan) 是近年來極具發展潛力的生醫材料，具有生物可分解性、生物相容性及抗菌性，且其在酸性環境下會形成帶正電的聚電解質，可以很容易的和其他帶負電的聚電解質或藥物形成錯合物，藉而增進材料的特性，因此應用極為廣泛，常被用於骨頭組織再生、藥物釋放、創傷敷料等應用。而聚麩胺酸 (??-PGA) 則為近幾年開發成功，全天然生物可分解性高分子，具有高度之親水、保水能力，有生物凝膠及保健食品等應用。
本實驗利用低分子量的幾丁聚醣與聚麩胺酸為材料來製備奈米載體。透過溶解於酸中帶NH3+基團的幾丁聚醣與本身帶COO- 基團的聚麩胺酸，可以形成離子性複合奈米粒子，而藉由改變聚合物的組成比例可調控粒徑大小及表面帶電荷。從中選擇較佳處方並透過共聚法 (Coacervation) 的概念包覆藥物Docetaxel，其所形成的難溶性藥物奈米粒子可以做為聚合物離子性複合後的包覆核心，經由快速篩選與奈米粒子特性，如粒徑大小、表面帶電荷及藥物包覆率相關的影響因子，包括溶劑種類、界面活性劑濃度、製備體積及藥物含量等，再使用實驗設計軟體Design-Expert分析影響因子與奈米粒子特性相關性以尋求製程與處方最佳化，得到最適宜的奈米藥物粒子為核心，完成抗癌藥物奈米輸送載體的技術平台開發。

關鍵字

奈米粒子 ； 幾丁聚醣 ； 聚麩胺酸 ； 歐洲紫杉醇

並列摘要

There are several problems in conventional cancer treatment, including drug systemic side effect due to their non-specific, and the solvent used for those insoluble drugs in the clinical may cause hyperimmunity in patients. In order to solve the problems, our study focuses on the formulation of biodegradable carrier incorporation with insoluble anticancer drug, Docetaxel.

The size of nanoparticle is generally accepted definition of a size of 10-1000nm, and an ideal model of nano scale drug carrier should be more specific drug targeting and delivery；reduction in toxicity while maintain therapeutic effects；greater safety and biocompatibility. Therefore, the main issue in preparing nanoparticle is the incorporation and release of drug；formulation stability and shelf life；biocompatibility, and biodistribution and targeting.

Chitosan (CS) is one of the recently highly developed biomaterials, which is potential according to its nature of biocompatibility, biodegradable and non-toxicity. Besides, chitosan is soluble in weak acid and positively charged. These unique features of chitosan have developed for a wide use for negative charge drug or ion complex, and their variety application in life sciences field. Poly glutamic acid (??-PGA) is anionic peptide with water-soluble, biodegradable, and nontoxic features, which is well developed in recent years in nutrient, medicine and cosmetic

industries owing to its water absorption and conservation.

In this study, preparation of nanoparticles drug carrier composed of low-MW CS and ??-PGA through a simple and mild ion-gelation method upon addition of ??-PGA solution into CS solution. The particle size and zeta potential value of the prepared nanoparticles can be controlled by their constituted compositions. For incorporation Docetaxel, the drug must be entrapped during the coacervation process of preparing CS-??-PGA nanoparticles.

There are several factors effecting the particle size and drug encapsulation efficiency was discussed, which including the type of organic solvents and surfactant concentration, sonication time and power, mixing order of the organic phase, total volume and drug amount. In order to choose the best formulation and preparation process, the use of software for design of experiment ---Design Expert is really helpful to rapidly design and analyze the relation among factors. In conclusion, the Docetaxel loaded CS-??-PGA nanoparticles would be able to be the core of drug carriers or an effective drug delivery platform.

並列關鍵字

nanoparticles ； chitosan ； r-PGA ； Docetaxel

參考文獻

1. Kukowska-Latallo, J.F., et al., Nanoparticle targeting of anticancer drug improves therapeutic response in animal model of human epithelial cancer. Cancer Research, 2005. 65(12): p. 5317-5324.

2. Zhang, L., et al., Nanoparticles in medicine: therapeutic applications and developments. Clinical Pharmacology & Therapeutics, 2007. 83(5): p. 761-769.

5. Schnyder, A., et al., Targeting of daunomycin using biotinylated immunoliposomes: pharmacokinetics, tissue distribution and in vitro pharmacological effects. Journal of drug targeting, 2005. 13(5): p. 325-335.

6. Kabanov, A.V., E.V. Batrakova, and V.Y. Alakhov, Pluronic< sup>R block copolymers as novel polymer therapeutics for drug and gene delivery. Journal of Controlled Release, 2002. 82(2): p. 189-212.

7. Wong, H.L., et al., < i> In vivo evaluation of a new polymer-lipid hybrid nanoparticle (PLN) formulation of doxorubicin in a murine solid tumor model. European journal of pharmaceutics and biopharmaceutics, 2007. 65(3): p. 300-308.