以幾丁聚醣為基質製備應用於藥物釋放之組織工程多孔性支架

Preparation of Chitosan-based tissue ngineering scaffold suitable for drug delivery application

葉志宗(Chin-Tsung Yeh)

指導教授 ： 林忻怡

國立臺北科技大學/工程學院/化學工程研究所/碩士(2009年)

摘要

在前人的研究中，幾丁聚醣常製成微粒及薄膜作為藥物輸送系統的載體，或是製成多孔性支架以作為細胞培養之基材，進而對受損皮膚或骨組織進行修復。然而多孔性支架也常作為體內實驗中包覆成長因數或抗發炎與抗菌藥物的載體，研究其對藥物釋放表現的影響，但在過去的研究中卻鮮少有人對藥物釋放率及藥物作用時間進行探討。
本研究將天然的幾丁聚醣(C)分別與褐藻酸鈉(A)、果膠(P)及槴子素(G)進行交聯，並製成多孔性支架與薄膜；實驗以抗發炎藥物己酮可可鹼(PTX)作為藥物輸送系統中的承載藥物，研究其釋放性質(膨潤率、藥物釋放率、抗發炎測試)，並對交聯後的鍵結變化(傅立葉轉換紅外線光譜)、熱性質(熱重分析)、親水性(接觸角)、結構形態(掃描式電子顯微鏡)、機械強度(楊氏係數)、生物相容性(細胞貼附)與酵素降解性等物理性質進行探討。
由傅立葉轉換紅外線光譜結果可知，幾丁聚醣(C)與槴子素(G)間產生醯胺鍵結，與褐藻酸鈉(A)或果膠(P)交聯則僅產生胺基/羧酸基混合吸收峰，且吸收峰訊號強度隨著交聯比例改變。熱重分析顯示幾丁聚醣(C)與褐藻酸鈉(A)或果膠(P)交聯後，裂解溫度介於幾丁聚醣與交聯分子之間，可知其交聯的作用力為陰陽離子吸引，僅產生離子鍵結；幾丁聚醣(C)與槴子素(G)交聯後裂解溫度上升，表示分子間產生共價鍵結。由掃描式電子顯微鏡觀察，經褐藻酸鈉(A)或果膠(P)交聯後支架具有較緻密結構與較小的孔隙，而經槴子素(G)交聯後支架結構並沒有明顯的改變。幾丁聚醣(C)除與槴子素(G)交聯後親水性變差，其餘交聯分子(A、P)皆可提昇支架的親水性。
此外，不管以幾丁聚醣與何種分子交聯，皆可增加機械強度並降低酵素降解所損失的重量比率。幾丁聚醣(C)與褐藻酸鈉(A)或果膠(P)交聯後薄膜親水性較佳，其骨母細胞(7F2)貼附速率較幾丁聚醣薄膜快，而與槴子素(G)交聯的薄膜則因親水性變差，使得骨母細胞貼附速率則比幾丁聚醣薄膜慢。由於幾丁聚醣(C)經交聯後對多孔性支架結構及親水性的改變，交聯後支架膨潤率較低。且經過交聯的支架在藥物釋放實驗中，具有較低的釋放率。從抗發炎實驗中可發現，藉由交聯支架的緩慢釋放特性，可使抗發炎藥物PTX能有效抑制發炎反應。從上述實驗結果可知，當幾丁聚醣(C)經交聯製成多孔性支架，能有效降低藥物釋放率；延長藥物釋放時間，並增加用藥的效率及藥物作用時間。

關鍵字

幾丁聚醣 ； 褐藻酸鈉 ； 果膠 ； 槴子素 ； 抗發炎 ； 藥物釋放

並列摘要

It’s known that crosslinking of chitosan can made beads and films to treat as carrier of drug delivery system. Or made to porous scaffold and create a stiffer surface to enhance cell attachment and proliferation. Porous scaffold also can treat to as carrier of growing factor, anti-inflammation drug and anti-bacterial drug for in vivo experiment, to study drug delivery behavior. But less bypast research were study to drug release efficiency and drug working time.
The purpose of ours research was to modify porous chitosan (C) tissue culture scaffolds and to make them suitable for controlled drug release. Chitosan (C) and chitosan differentiate to crosslinking with alginate (A), pectin (P) and genipin (G) in different proportions were made into porous scaffolds and thin films. FT-IR and thermal gravimetric analysis were used to define the type of crosslink. The hydrophility (contact angle) was tested as plate. Morphology (SEM), mechanical property (Young’s modulus) and enzymatic degradation of the CS hybrid scaffolds were measured. In the experiment, anti-inflammation drug [Pentoxifylline (PTX)] was to take as the model drug to determine their controlled release properties (swell ratio, drug release efficiency and anti-inflammatory test) and biological property (cell adherent) was tested as well.
Amide (N-C=O) bonding was seen in FT-IR spectra of C/G hybrid scaffold. Amine/Carboxyl mixing peak was seen in FT-IR spectra of C/A and C/P scaffold. And the strength of signals was change with crosslinking proportion. New decomposition temperature of C/A and C/P were between C and crossslinking agents. That was confirmed the driving force of crosslinking with ALG and PEC were ionic attraction, and made ionic bond. Because the covalent bond between C and G, C/G had higher decomposition temperature. The C/A and C/P scaffolds had smaller pores and a more compact structure than the CS scaffolds. The pores of C/G scaffolds were similar to CS scaffold. C/A and C/P were more hydrophilic, but C/G was less hydrophilic.
All Chitosan hybrid scaffolds were mechanically stronger (higher Young’s modulus) and less susceptible to enzymatic degradation than chitosan scaffolds. Due to the hydrophilicity, osteoblast (7F2) adhered of C/A and C/P was faster than the chitosan films. But C/G was slower than chitosan films. On the controlled release perspective, as a result of the crosslinking and the charge of 3-D structure scaffold and relation of hydrophility, Chitosan hybrid scaffolds had lower swell ratio and lower drug release efficiency than chitosan scaffolds. In anti-inflammatory test, due to the slow release property of hybrid scaffolds, the efficacy of drug were be enhanced. The anti-inflammation drug can restrain inflammation helpful
In summary, the Chitosan hybrid scaffolds were better for slow down the anti-inflammation drug release efficiency. And lengthen the working time of drug release.

並列關鍵字

Chitosan ； Alginate ； Pectin ； Genipin ； Anti-inflammatory ； Drug release

參考文獻

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