以電紡絲法製備幾丁聚醣/聚氧化乙烯
暨Eudragit奈米複合基材及其應用

本研究以靜電紡絲法製備兩種結構並存的混合基材，其一為幾丁聚醣/聚氧化乙烯所形成的奈米纖維結構，其二是參雜其間由Eudragit所形成的顆粒結構，再藉由將顆粒溶解的方式，來調控奈米纖維的滲透率。因為幾丁聚醣屬於帶正電性的高分子，通常不易單獨電紡成奈米纖維絲，若搭配聚氧化乙烯後不但可以順利進行電紡，還能夠使用總濃度為3 wt%的甲、乙酸以7:3的比例混合作為溶劑，以避免使用具有高毒性、腐蝕性的有機溶劑如六氟異丙醇和三氟乙酸，使製程更為環保。為了形成兩種結構，本研究使用雙針電紡，且嘗試了從0.5 cm到3.5 cm不同長度的屏蔽環來克服雙針並排時容易產生靜電排斥力，互相干擾造成電紡結構不佳的問題，並發現了0.5 cm長的屏蔽環效果最佳，再搭配收集板的旋轉成功地收集到了兩種結構交錯分佈的電紡纖維/顆粒膜。在幾丁聚醣(C)/聚氧化乙烯(P)溶液總濃度為3 wt%前提下，改變C/P比例成為C2/P1、C2.25/P0.75和C2.5/P0.5這三組並電紡成纖維且均另搭配電紡Eudragit顆粒，藉由SEM的觀察發現雙針電紡可以得到纖維與顆粒交互堆疊的結構，也經由FT-IR分析確認基材含有原始混摻的材料所具有的官能基。在比較各種不同戊二醛交聯時間的效應，發現在交聯12 小時的情況下可順利地將C2.25/P0.75組別的基材強度從55.9±6.5 N/g提高到142.6±9.6 N/g，然而其延展性卻大幅降低。再將基材中的Eudragit顆粒溶解，只剩奈米纖維，則可以改變基材的滲透率，使其從2.97x10-6變成7.81x10-7 cm2/s。綜合以上所述，本研究藉由Eudragit顆粒可調控幾丁聚醣和聚氧化乙烯的奈米纖維膜之滲透率，並且藉由交聯大幅提升其基材強度，若能進一步改善其滲透率，未來可望應用於組織工程等相關領域中。

關鍵字

幾丁聚醣；聚氧化乙烯； Eudragit ；靜電紡絲法；戊二醛；屏蔽環；滲透率

並列摘要

In this research, a composite mesh containing two kinds of structure was fabricated by electrospinning; one is nanofibers composed of chitosan (C)/poly(ethylene oxide) (P), and the other one is beads made up of Eudragit. By dissolving the beads, permeability of the mesh can be adjusted. Chitosan is a positively charged polymer, so it’s difficult to fabricate it into nanofiber structure; With the addition of poly(ethylene oixde), chitosan can not only be fabricated into nanofibers, but can also be dissolved in formic/acetic acid of 7:3 ratio as solvent, with a relatively low 3 wt% concentration. The process would be more environment-friendly by using the solvent mentioned above instead of using highly toxic and erosive hexafluoroisopropanol (HFIP) or trifluoroacetic acid (TFA). A dual-jet electrospinning system was used to fabricate two different structures and shield rings with length of 0.5 to 3.5 cm were also used to overcome the electrostatic repulsion forces that may cause defect in nanofiber structure, which resulted from the using of the dual-jet system, and found that the 0.5 cm length of shield ring was the most effective. Afterwards, electrospun meshes with both nanofibers and beads were suceessfully collected on the rotating collector. C2/P1, C2.25/P0.75 and C2.5/P0.5 were the three groups with different chitosan (C)/poly(ethylene oxide) (P) ratios, all with 3 wt% total concentration. These groups of nanofibers were all combined with Eudragit beads and the stacking structure of the fibers and beads was observed under SEM; moreover, the functional groups of the original materials (chitosan, polyethylene oxide and Eudragit) were all confirmed by FT-IR analysis. The tensile strength of the composite mesh was examined after different cross-linking times, and that of the C2.25/P0.75 group was enhanced from 55.9±6.5 N/g to 142.6±9.6 N/g after 12 hours of cross-linking; however, the elongation at break enormously decreased. After that, the Eudragit beads in the mesh of C2.25/P0.75 group were dissolved, and the permeability values of the mesh decreased from 2.97x10-6 to 7.81x10-7 cm2/s. On the whole, in this research, the permeability of chitosan (C)/poly(ethylene oxide) (P) mesh was successfully adjusted along with the increased tensile strength. These results hold great potential for the future applications in tissue engineering-related fields.

並列關鍵字

Chitosan ； Poly(ethylene oxide) ； Eudragit ； Electrospinning ； Glutaraldehyde ； Shield ring ； Permeability values

參考文獻

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