設計和發展雙噴射電紡織法設計和發展雙噴射電紡織法 製造可控制纖維直徑及孔洞大小之支架

Abstract

電紡織技術可製造出奈米尺度的基質纖維，是近年來在再生醫學與組織工程的支架應用上非常熱門的研究之ㄧ。但是，利用電紡織技術所製得的支架，其厚度都很薄，且無法控制孔洞大小，為了解決此問題，我們選用明膠/三氟乙醇和聚己內酯/三氟醋酸溶液作為生醫材料，並以鹽溶濾法的概念，作為實驗主軸，分別製成奈米纖維絲和微米顆粒。 由於電紡織技術是利用不同參數，以獲得不同直徑大小的產物。所以我們利用正交實驗設計法，分別對不同參數如:濃度、電壓、流速，和針孔大小等，找出真正影響實驗的重要因子。 首先，控制濃度範圍在2.5 %~12.5%、電壓9~21 kV、距離3~6 cm、流速0.9~9 ml/h等，使用SPSS軟體分析各種參數和直徑的關係，可以發現真正影響實驗的參數，前後順序依次為:濃度、電壓、針孔大小，和流速，因此適當控制這些參數，可以得到50 nm~800 nm明膠奈米絲和10 μm~100 μm聚己內酯微米顆粒，提供後續步驟的選用。 接著，選用濃度7.5 %明膠/三氟乙醇溶液和濃度7.5 %聚己內酯/三氟醋酸溶液，以明膠作為奈米絲支架，聚己內酯作為微米顆粒扮演製孔劑的角色，兩者同時噴射，並使用特別設計的旋轉裝置，使其達到適當均勻混合，之後，針對明膠的低抗濕性，以25 %戊二醛蒸氣，依照不同時間做適當交聯，再使用丙酮當作溶劑，溶解聚己內酯，達到我們想要的孔洞大小，並乾燥之，則可得到可控制孔洞大小的奈米支架。 另外，為解決厚度問題，特別設計棉花機裝置，不同於以往平面的收集方式，可得到3-D的棉絮狀產物，產物可分別於鐵絲網上和三角錐鐵絲上收集之，得到有厚度的支架，且由鐵絲網所收集的網狀結構具有某方向性排列。

Electrospinning can fabricate nanofibers, the most popular material in building scaffold for the field of regenerative medicine and tissue engineering. Yet, scaffolds retrieved from electrospinning are too thin, and the pore size are uncontrollable. In order to solve these problem, this study tried to conduct the experiments based on the concept of salt-leaching, and using gelatin/ 2,2,2trifluroethanol and poly-carpolactone/ trifluoroacetic acid as primary materials to create gelatin nanofiber and PCL microparticle respectively. Many parameters will affect the results of electrospinning. Therefore,in order to find out the most important factor in controlling the experimented results, we used orthogonal design method to investigate the interation of different parameters such as concentration, voltage, flowing speed and needle size. First, we controlled the concentration within 2.5 % to 12.5 %; voltage 9 kV to 21 kV at 3 kV increment intervals; flow rate 0.9 ml/h to 9 ml/h. SPSS software was used to analyze the relationship between different parameters and diameters. We found that the concentration is the most important factor, followed by voltage, needle size, and flowing speed. Nanofiber ranging from 50 nm~800 nm and PCL microparticle 10 μm~100 μm for further usage were created when the factors were under control. 7.5 % w/v gelatin/TFE solution and 7.5 % w/v PCL/TFA solution were used as raw materials and electrospun at the same time. A rotation device was especially designed to have the composite well mixed. The electrospun gelatin nanofibers were crosslinked with 25 % saturated glutaraldehyde (GTA) vapor at room temperature in a Petri dish under different time duration. Then acetone was used to dissolve PCL particle to obtain desirable pore sizes. Experimental results show that the study successfully designed and achieved a scaffold of nanofibers with desirable pore sizes using electrospinning technique. As an appendix, a device similar to sugar puff machine was built to cope with the problem of thickness. 3-D cotton fibers were collected from both wire meshes and trigonometric wire. Scaffolds with thickness were obtained and the fibers collected were uniaxially aligned.