功能性二氧化矽奈米短纖/PF127溫感型水膠複材對PC12細胞之影響

近年來雖然醫學技術的突飛猛進，但以現今技術來說要治療神經系統相關疾病仍然是一項困難的課題，因此創造出適合神經細胞生長的環境與如何快速修復神經系統，至今一直是所有醫學界待解決的問題之一。本實驗室先前即利用此技術製備出二氧化矽奈米纖維基材，並且透過物理吸附與化學接枝等方式將層粘連蛋白(Laminin)修飾至基材上。從實驗結果得知，不論透過物理吸附或化學接枝等固定化層黏連蛋白，皆具有促進類神經細胞的貼附能力，而且使用化學接枝的方式可以使基材降解速度低於物理吸附與未修飾的基材。然而由於基材皆製備於玻璃基板上，若未來需應用至體內移植材，勢必要改變基材型態。水膠為一高分子鏈經由物理或是化學性交聯後所形成的親水性三維網狀膠體，其吸水後產生澎潤現象，在澎潤狀態下具有柔軟且富有彈性的性質，與人類組織類似，是良好的藥物載體。因此本研究方向為(1)利用冷凍切片法，將順向的二氧化矽奈米纖維(SNF)轉變成二氧化矽奈米短纖維(fSNF)；(2)將fSNF分別以物理吸附(fSNF/R)與離子鍵結(fSNF/SR)兩種方式修飾RGD(R)與SBP-RGD(SR)胜肽；(3)利用市售的PF127溫感型水膠作為載體，將fSNF、fSNF/R與fSNF/SR基材結合，成為fSNF-PF127、fSNF/R-PF127與fSNF/SR-PF127複合材；(4)最後以大鼠腎上腺髓質嗜鉻細胞株 (PC12 cells)為細胞模式，探討不同的fSNF-PF127複合材，對於PC12細胞的毒性、增生與分化能力等影響。研究結果顯示，材料鑑定部分利用SEM證實透過冷凍切片法所得到的fSNF與預期的長度25 μm與50 μm差異不大，再者經FT-IR、TGA與BET證實，已將電紡中所添加的增稠劑PVP與冷凍切片法所用的包埋劑去除；而透過PC12細胞實驗可知，利用30 wt% PF127水膠與fSNF形成的複合材對於細胞並沒有毒性，細胞增生與分化的結果得知，fSNF/SR-PF127能夠促進細胞分化能力長達18天之久。因此利用離子鍵結修飾的複合材很適合應用至神經組織工程上。

關鍵字

靜電紡絲；二氧化矽奈米短纖；PC12；PF127；溫感型水膠

並列摘要

Our laboratory previously prepared Silica Nanofiber (SNF) by electospinning technique, and modified laminin to SNF by physical adsorption and chemical grafting. From the results, it is known that whether immobilized laminin through physical adsorption or chemical grafting, it has ability to promote the adhesion of PC12 neurons, and the use of chemical grafting can make the degradation rate of the substrate lower than that of physical adsorption with unmodified substrate. Thus, we transformed Silica Nanofiber (SNF) to Fragmented Silca Nanofiber (fSNF) by frozen tissue section, modified RGD SBP-RGD peptide with physical adsorption and ionic bonding. Using commercial PF127 temperature-sensitive hydrogel as a carrier, fSNF, fSNF/R and fSNF/SR are combined to form fSNF-PF127, fSNF/R-PF127 and fSNF/SR-PF127 composite materials. We uses PC12 neuronal cell as model, investigating the effects of different parts of fSNF-PF127 composite materials on the toxicity, proliferation and differentiation of PC12 cells. Through PC12 cell experiments, it seems that the composite formed by 30 wt% PF127 hydrogel and fSNF are nontoxic to cells. fSNF/SR-PF127 can promote cell differentiation for up to 18 days. Therefore, composite materials modified by ionic bonding are very suitable for neural tissue engineering.