冷電漿表面改質及接枝聚合於生醫材料之應用

Surface Modification of Bio-materials by Cold Plasma Treatment and UV Induced Graft Polymerization

陳素真(Su-Chen Chen)

指導教授 ： 陳克紹

大同大學/工程學院/材料工程學系所/博士(2006年)

摘要

本研究主要利用電漿改質及UV光接枝聚合方法，在材料表面進行一系列的改質，並利用生物分子固定化技術將生物分子如明膠及DNA固定在材料表面，以應用至感溫易剝離敷料或生物感測器。在感溫易剝離敷料方面，因不織布敷料本身具多孔性、表面積大、高孔隙率、無塵、易加工、可供表面改質機能化等特點，在其表面經適當處理後可將生物分子固定於其上，將是一非常理想的創傷批覆材。因此，為了達到此目的，是利用異丙基丙烯醯胺(NIPAAm)單體由於其特殊的臨界溫度(約32℃)轉換特性，具有高溫疏水且低溫親水膨潤的優點，而具有易剝離效用，可減輕病人換藥或組織修復後敷料撕離時的疼痛。本實驗先利用Ar氣電漿活化前處理，再與感溫性單體NIPAAm進行表面接枝聚合，藉由其特殊之溫度敏感性，作為不織布與明膠間的中間層，以便將來取下時不會造成傷口的二次傷害，最後，配合戊二醛交聯劑的添加，即可與生解性高分子明膠進行複合交聯，而形成一感溫易剝離創傷披覆材，主要探討不同戊二醛交聯條件對明膠強度的影響以及對生物適應性的效應。並以纖維母細胞及角膜細胞培養來評估，方能瞭解相關生物適應性的結果，確立此一敷料在創傷治療應用上的價值。從SEM的型態觀察可發現三層敷料的層間構造及多孔狀明膠層的存在，並從細胞培養評估，如細胞貼附、MTT檢驗等結果，都證明此三層敷料具良好的生物相容性。
在生物感測器方面，主要是應用電漿改質及UV光接枝聚合方法在QCM感測元件表面固定腸炎弧菌(Vibrio parahaemolyticus)的DNA以用來其檢測腸炎弧菌的有無，石英晶體微天平(QCM)是一質量感測元件，當其表面吸附物質時可由振動頻率之增減檢測出吸附的量，它可提供具有高選擇性且及時監控雜交可能性的系統。在本實驗中透過固定Vibrio parahaemolyticus特有的單股核酸片斷在QCM表面做為探針用來檢測Vibrio parahaemolyticus的有無。本實驗是利用電漿改質於QCM表面沉積六甲基二矽氨烷（HMDSZ）薄膜，以作為無機物與有機分子的介面層，即可利用架橋劑戊二醛（GA），將胺基化寡核苷酸以化學鍵結的方式固定於QCM表面。主要探討電漿沉積後接枝親水性單體AAm及PEI胺基擴增等後處理對探針固定量之影響，並且藉由ESCA及AFM等表面分析方法來證實各個改質處理的有無。結果證實利用電漿沉積法沉積有機膜後, 經由戊二醛交聯後確實可將胺基化寡核苷酸固定於QCM上，且在電漿沉積有機矽膜後再接枝親水性單體AAm以及polyethyleneimine(PEI)處理後，可因表面-NH2量增加，而提高寡核苷酸固定量。其偵測靈敏度可至86 ng/ml，且其儲存安定性在0℃冰箱中存放11天後尚有88.7%，再生性以0.1MNaOH清洗後，重複使用7次時仍可達60%的檢測效率。

關鍵字

電漿處理，接枝聚合，表面改質，生醫材料，生物感測器

並列摘要

In this study, we used plasma treatment and photo-induced grafting polymerization technologies to surface modify the character of materials for applications to biosensor and biomaterial fields.
For biomaterial application, we fabricate an easy-strip gelatin scaffold on surface of PNIPAAm gel /polypropylene (PP) nonwoven to application in wound dressing. Nonwoven have wide industrial application due to its cheapness, low density, excellent mechanical properties and high porosity. However, due to lack of chemical functionalities, the hydrophobic natures of these surfaces have restricted the use of polypropylene. Hence, in this study, we used thermal-sensitive culture scaffolds to develop a novel easily-stripped cell membrane manipulation to cure different cells. The cell membrane was fabricated by Ar plasma treatment and photo-induced graft-polymerization thermo-sensitive monomer N-isopropylacrylamide (NIPAAm) to modify the surface character of PP nonwoven. Then, after immobilization of the porous gelatin as cell membrane, it can be easily removed from PNIPAAm gel when it is immersed in cold water. The stability of the carrier materials under in-vitro conditions and proliferation of the cells was investigated by SEM and MTT test. Microscopic investigation showed that corneal epithelium cell morphology is stretched out along the length of the gelatin and even penetrated into the inner gelatin organization. Furthermore, the results of SEM and HE staining also showed that corneal epithelium and fibroblasts cells could attach to the scaffold. The porous structure of the gelatin scaffold provided an excellent space that was suitable for cell growth in this circumstance. Thus membrane-transferred corneal epithelium stem cells can be used to regenerate corneal epithelium in the eye or fibroblasts cell in the skin.
Secondly, biosensor technology offers the possibility of monitoring hybridization in real time and with high selectivity. In this study, we developed a sensing system for detection of Vibrio parahaemolyticus using its oligonucleotide probe immobilization on the gold electrode surfaces of QCM. However, since the QCM surface was an inorganic substance, it is difficult to immobilize the oligonucleotide probe. In this study, the plasma surface modification of QCM for deposition of hexamethyldisilazane (HMDSZ) films as an interlayer was investigated. This provided good adhesion to the substrate and had a uniform structure. Then, we use chemical bonding to immobilize the DNA probe on the amino surface via a glutaraldehyde (GA) linker. The effect of post-treatment of the immobilized process, such as surface graft AAm and PEI treatment, is compared and the determinate limit for this way is discussed. The surface properties after each modification process were verified by water contact angle and ESCA spectra. The results demonstrate that the shift of resonance frequency of QCM was improved via subsequent graft polymerization of AAm and PEI treatment onto the electrodes. The QCM sensor after plasma deposition and surface modification could provide detection sensitivity up to 86 ng/ml and retained 90% detection sensitivity after 11 days of storage at 0oC. After washing with 0.1 M NaOH solution and 7 of repeated uses for detection, the regeneration rate of QCM could be as high as 60%.

並列關鍵字

biomaterials ； Plasma treatment ； biosensor ； photo-induced grafted polymerization ； surface modification

參考文獻

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