褐藻酸鈉所製備纖維支架，其負電特性可用來吸附帶正電的聚乙烯亞胺/基因納米粒子，藉由增加纖維的用量，可以增進轉染的效果，然而褐藻酸鈉對於細胞生物相容性不佳。因此我們導入了具生物相容性的聚己內酯來進行混合紡絲，SEM照片與纖維螢光染色中證實纖維的比例可以依照需求來調整，接觸角與紅外光譜儀之測試中也顯示複合纖維之性質會隨組成比例不同而改變。將不同組成比例之複合纖維來進行粒子吸附後進行轉染，發現聚己內酯纖維比例的提高可以增加材料的生物相容性，但是粒子的吸附量也隨之下降。為兼具轉染效果與生物適合性，我們利用EDTA來降解褐藻酸鈉纖維，結果發現在培養初期褐藻酸鈉纖維結構仍可維持以用於吸附粒子，在細胞攝入粒子後褐藻酸鈉纖維會逐漸被降解，只留下聚己內酯纖維，使細胞在攝入基因後得以存活於合適的環境。最後，為了要臨床應用需求，我們透過調整鈣離子的濃度來改變褐藻酸鈉纖維的交聯程度，並於結果發現，降低交聯程度會使纖維的結構較不穩定而會逐漸自行降解，亦可達到兼具轉染效果與生物適合性的效果。這些結果皆顯示利用可降解釋的複合支架來進行送藥並提升生物活性將有利於組織工程的應用。 To regulate in situ gene delivery from biomaterial scaffolds, electrospun alginate nanofibers were applied to adsorb DNA/polyethylene (PEI) complex. The transfection efficiency increased with increasing deposited nanofibers. However, alginate was not favor for cell adhesion. Therefore, biocompatible poly (ε-poly olactone) (PCL) nanofibers was coelectrospun with alginate to increase biocompatibility. The scanning electron microscopy and fluorescent dye staining results suggested that the definite fiber ratios could be controlled. In addition, contact angle and FT-IR results also indicated that the properties of composite fibers can be regulated by the fiber ratios. The in situ transfection results demonstrated that the incorporated PCL fibers improved biocompatibility however, the transfection efficiency was reduced. To preserve both gene transfer ability and biocompatibility, EDTA was applied to remove calcium ions for loosening alginate fiber structure. This treatment may initially maintain alginate fibers for nanoparticle adsorption, but these alginate fibers were gradually degraded in days to create a more appropriate environment for cell survival. For clinical application, we tried to regulate calcium concentration during fiber crosslinking to control the stability of alginate fibers. Though decreasing the levels of crosslinking, alginate fibers were degraded with time, which promoted both transfection efficiency and biocompatibility. These results supported biodegradable composite scaffolds should be potential for drug delivery with excellent bioactivity, which should be beneficial for tissue engineering applications.
