具自由胺基微胞之合成與特性分析及於藥物釋放之應用—聚己內脂-幾丁寡醣-聚乙二醇雙性共聚合物

Synthesis and Characterization Micelles that Contain Free Amine Groups — Amphiphilic Poly (ε-caprolactone) – Chitooligosaccharide – Poly (ethylene glycol) copolymer and its applications in Drug Delivery

楊政典(Jean-Dean Yang)

指導教授 ： 鍾次文 ； 謝瑞香

中原大學/工學院/醫學工程研究所/碩士(2004年)

https://doi.org/10.6840/cycu200400282

摘要

幾丁聚醣(Chitosan, CS)及幾丁寡醣(Chitooligosaccharides, COS)為天然且具生物相容性之陽離子多醣體(Cationic Polysaccharides)，而幾丁寡醣製備時通常利用酸或酵素之降解或水解作用將幾丁聚醣降解或水解而成。
在本研究中，以幾丁寡醣為起始材料經過一化學改質將分子內及分子間之氫鍵破壞，使其可溶解於一般之有機溶劑。另外,將自行聚合之單甲基聚己內酯(m-PCL)與甲氧基聚乙二醇(m-PEG)分子鏈上一端的羥基(Hydroxy group)以共價鍵(Covalent bond) 鍵結接上二異氰酸(Diisocyanate)之一端，而另一端保有具活性異氰酸之單甲基聚己內酯與甲氧基聚乙二醇預聚合物(Prepolymer)。再之,將此預聚合物分別與幾丁寡醣之羥基反應接枝(Graft)，而形成聚己內酯-幾丁寡醣-聚乙二醇(PCL-g-COS-g-PEG, PCP) 接枝共聚合物，並利用傅立葉轉換紅外線光譜儀(Fourier-Transform Infrared Spectrometry, FT-IR)以及核磁共振光譜儀(Nuclear Magnetic Resonance, NMR)光譜圖來分析與描述其特性。
而此PCP接枝共聚合物利用直接形成法(Direct dissolution)製備成為PCP微胞(Micelle)，PCP聚合物形成微胞之臨界膠體濃度(Critical Micelle Concentration, CMC)為8×10-3 ~ 1.6×10-2 wt.% (80 ~ 160 mg/L)。PCP共聚合物所形成之微胞利用雷射光散射粒徑分佈分析儀 (Light Scattering Particle Size Distribution Analyzer, LSC)及穿透式電子顯微鏡(Transmission Electron Microscopy,　TEM )觀察微胞之尺寸與形態，結果顯示微胞之尺寸分佈約為40 - 120 nm。
由於PCP結構中含有COS，COS分子中含有胺基(Amine groups)，因此本研究針對此一特性對微胞加以應用研究。其一：於微胞形成後利用自由胺基做化學交聯(Cross-link)探討微胞之穩定性；其二：在自由胺基上接枝具貼附細胞之因子– (Arg-Gly-Asp, RGD)，作細胞uptake之試驗。其結果顯示，透過化學交聯後所形成之交聯PCP微胞，在37℃條件下尺寸穩定時間長達48 小時。將鍵結上RGD之RGD-PCP微胞利用PC-12細胞作uptake試驗，結果發現有鍵結上RGD之微胞明顯的比一般的PCP微胞被PC-12細胞uptake為快。
在本研究中所發展的PCP微胞結構中，保留許多的自由胺基，此官能基可以提供了許多不同的功能需求，諸如：基因傳遞、酵素儲存、或是一個多樣化的藥物儲存的空間，而此形式微胞於藥物釋放系統中將有助於藥物傳遞的穩定性以及藥物之標地(Target)功能。

關鍵字

聚乙二醇 ； 聚己內脂 ； 幾丁寡醣 ； 微胞

並列摘要

A new biodegradable amphiphilic copolymers, Poly (-caprolactone) – chitooligosaccharide – poly (ethylene glycol) (PCL-g-COS-g-PEG, PCP) which contains free amine groups of COS, were synthesized and characterized. The characteristics of the PCP copolymers were examined by 1H Nuclear magnetic resonance (1H NMR), Fourier-transform infrared spectrometry (FT-IR) for function group analysis and Gel permeation chromatography (GPC) for determining molecular weight. The PCP copolymers can self-assembly to form micelles at the critical micelle concentration (CMC) about 8×10-3–1.6×10-2 wt.% (80 ~ 160 mg/L), determined by measuring UV-VIS absorption spectra of DPH loaded PCP micelles. Moreover, the average diameter of PCP micelles were 68.5 nm measured by a dynamic light-scattering (DLS) analyzer. The morphology of micelles was observed by Transmission Electron Microscopy (TEM) with sizes ranged from 20 to 120 nm.
After the PCP copolymer was grafted with RGD by photochemical technique based on phenyl azido chemistry. For comparing the targeting capability of micelles, the RGD grafted PCP micelles (RGD-PCP) and PCP micelles was used to target PC-12 cell in vitro study. The results showed that RGD-PCP micelles were faster targeting capability than PCP micelles, and the free amine group of PCP micelles could be further crosslinked using a natural crosslinker, such as genipin, to improve the stability of the micelles.
The new synthesized PCP copolymers and micelles containing amine groups can be further applied by chemical modification for drug delivery.

並列關鍵字

chitooligosaccharide (COS) ； Poly (ethylene glycol) (PEG). ； Micelle ； Poly (e-caprolactone) (PCL)

參考文獻

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