以靜電紡絲法製備電活性聚鄰甲氧基苯胺/明膠纖維及其在組織工程之潛在應用探討

Electrospun Electroactive Poly-(o-methoxyaniline)/Gelatin Fibers with Potential Application in Tissue Engineering

林冠鎰(Kuan-Yi Lin)

指導教授 ： 李文婷

中原大學/工學院/生物醫學工程研究所/碩士(2012年)

https://doi.org/10.6840/cycu201201051

摘要

利用靜電紡絲技術將複合材料製備成細胞支架，可提供類細胞外間質的環境以及較大的表面積和孔洞率，並使支架具有多種功能，可以提升其在組織工程應用。本研究目的在提升聚鄰甲氧基苯胺 (POMA) 靜電紡絲之生物相容性，並探討其在組織工程之應用。本研究所合成 POMA 的重量平均分子量為 45880 Dalton，在電紡溶液中混合 20 分鐘，黏度快速上升至 71.9 cP；5% (w/v) 為電紡出奈米纖維之最佳濃度。將 5 % (w/v) POMA 與 17 % w/v 明膠以 70:30 體積比混合成功製備出 POMA/明膠 (PG) 電紡絲；以 5% (w/v) 檸檬酸作為摻雜劑可製備出具有導電率之電紡絲 (PGC)。POMA、PG 及 PGC 電紡絲的直徑分別為 356±58、306±55 及 269±40 nm。POMA 表面接觸角為 109±2o；而 PG 及 PGC 則不具接觸角，將其交聯後 PGE 及 PGCE 的接觸角提升為 28±3o 及 30±3o。PGE 及 PGCE 的交聯程度分別為 64.23±7.41 %、74.11±1.44 %；交聯後材料的最大熱失重溫度比交聯前高出 15-20 oC。循環伏安法分析發現 POMA、PGE 及 PGCE 電紡絲具有氧化還原能力；但只有添加摻雜劑的 PGC 及 PGCE 組別能夠量測到導電率，分別為 3.31±0.19 x 10-5、5.85±0.49 x 10-6 S/cm。相較於未摻雜的 PG，PGC 中 POMA 的苯環與醌環吸收峰由 316、623 nm 紅移至 424、760 nm，進一步驗證檸檬酸摻雜可使 POMA 由鹼式中間氧化態轉變成鹽式中間氧化態。POMA 不具降解性，而 PGE 及 PGCE 則具生物可降解性，纖維型態分別能維持 1、8 天。人類脂肪幹細胞 (hASCs) 及大鼠心肌原細胞 (H9c2) 貼附及生長於 PGE 及 PGCE 的情形均較 POMA 為佳。進一步施加電場刺激，可使 hASCs 細胞長度增加並且呈現兩極化生長，並提高 H9c2 細胞分化成肌小管的能力。本研究證實 POMA 混合明膠並摻雜檸檬酸的電紡絲可使其生物相容性大幅提升，未來可應用於組織工程。

關鍵字

聚鄰甲氧基苯胺 ； 奈米纖維 ； 生物相容性 ； 靜電紡絲 ； 組織工程 ； 導電高分子

並列摘要

Composite scaffold prepared by electrospinning technology can provide extracellular matrix-like environment, large surface area, high porosity, and multifunctionality, thus increases their application in tissue engineering. The purpose of this study was to enhance the biocompatibility of electrospun poly(o-methoxyaniline) (POMA) fibers and to explore its potential for tissue engineering application. Average molecular weight of POMA synthesized in this study was 45880 Dalton. Viscosity of the solution for electrospinning increased rapidly to 71.9 cP within 20-min mixing. The optimal concentration of POMA for electrospinning nanofibers was 5 % (w/v). POMA/gelatin (PG) electrospun fibers were successfully prepared using a mix of 5 % (w/v) POMA and 17 % (w/v) gelatin in a volume ratio of 70:30. Eletrospinning mats (PGC) with conductivity was made when doped with 5 % (w/v) citric acid. The average diameters of POMA, PG, and PGC nanofibers were 356±58, 306±55, and 269±40 nm, respectively. Contact angle of POMA was 109±2o, and those of PG and PGC were 0o. After crosslinking, contact angles of PGE and PGCE were 28±3o, and 30±3o, respectively. The degrees of crosslinking for PGE and PGCE were 64.23±7.41 % and 74.11±1.44 %, respectively. The maximal temperature of weight loss increased 15-20 oC after crosslinking. Cyclic voltammetric analysis found that POMA, PGE and PGCE had redox capability. Only doped PGC and PGCE had measured conductivity of 3.31±0.19 x 10-5 and 5.85±0.49 x 10-6 S/cm, respectively. Compared to undoped PG, the absorption wavelengths of 316 and 623 nm corresponding to benzene ring and the quinone ring of POMA were red-shifted to 424 and 760 nm in PGC, which further validated citric acid doping could change the state of POMA from emeraldine base to emeraldine salt. POMA nanofibers were non-biodegradable. PGE and PGCE nanofibers were biodegradable where fibrous morphology maintained for 1 and 8 days. Human adipose stem cells (hASCs) and rat cardiac myoblast (H9c2) showed improved attachment and proliferation on PGE and PGCE compared to POMA nanofibers. Furthermore, applied electric field could increase cell length as well as the cell polarization of hASCs, and enhance the differentiation ability of H9c2 cells into myotubes. In summary, citric acid doped nanofibers of POMA blended with gelatin were found to exhibit improved biocompatibility and could be applied in tissue engineering in the future.

並列關鍵字

poly(o-methoxyaniline) ； tissue engineering ； conducting polymer ； nanofiber ； biocompatibility ； electrospinning

參考文獻

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