摘要
在組織工程的研究裡，常遭遇到植入生物體內後的人工細胞外間質血管增生不足，造成遷入的細胞與新生的組織無法獲得充分的氧氣與養分。為了解決這項問題，文獻中曾有研究群在人工細胞外間質內加入生長因子，以促進其內的血管增生。目前用來當做促進血管增生的生長因子大部分都是蛋白質，其在生物體內的穩定性不佳，很容易失去其活性。為了克服這項問題，我們著手使用了從中藥〝人參〞裡，萃取純化出來的ginsenoside Rg1 (Rg1)與ginsenoside Re (Re)來當做新型的促進血管生長因子。
本研究主要分成三部份來進行。在第一和第二部分的實驗裡，我們以體外細胞培養測試的方式，分別評估了Rg1與Re對人類臍帶靜脈內皮細胞(HUVECs)的增殖、遷徙以及tube formation的影響。實驗裡，我們以在細胞培養基中未添加任何藥物當做空白對照組，而以在細胞培養基中加入bFGF當做正對照組。在本部份的實驗裡，我們證實了Rg1與Re具有與目前文獻上使用的血管生長因子(如bFGF)相同的特性，可以促進HUVECs增殖、遷徙以及tube formation的能力。同時我們也發現Rg1較親水，而Re則屬疏水性藥物。
在第三部分的體內實驗裡，我們以genipin交聯經醋酸膨潤與酵素處理的去細胞牛心包膜，當做人工細胞外間質(ECM)，然後把Re以gelatin包覆在ECM (ECM/Re)內後植入老鼠背部，探討Re在生物體內對血管增生以及組織再生與修復的影響。Rg1的體內實驗探討已由本實驗室博士班學生 梁晃千學長完成。實驗裡的對照組為bFGF (ECM/bFGF)，以及未包覆任何生長因子的ECM (ECM/ control)。在實驗設計上，我們分別於1星期與1個月後取樣，針對植入後人工細胞外間質內的血管增生數目、免疫反應、細胞遷入種類與滲入數目(infiltrated cell number)、組織修復時新生的細胞外間質組成以及變性溫度等加以評估。
實驗結果顯示，ECM/Re與ECM/bFGF在植入1星期後，老鼠的免疫細胞、內皮細胞以及紅血球都可以滲進多孔性結構的ECM內部。ECM/control內免疫細胞的數目明顯的比其他兩種試片來得多，但新生血管滲入包覆bFGF或Re的 ECM密度、深度以及hemoglobin含量，都明顯的比未包覆任何生長因子的ECM 來得多，這個現象顯示了包覆bFGF或Re的ECM可以明顯促進ECM內的血管增生。
植入1個月後，ECM/Re的外層孔洞結構內免疫細胞已經消失殆盡，取而代之的為宿主遷徙進來的纖維母細胞，以及其所分泌的結締組織和供應養分與氧氣的新生微血管。另外在ECM/bFGF的外層結構內也可以觀察到組織再生的情形，但仍有相當數目的免疫細胞存在，而ECM/control結構內組織再生的情形則較不明顯且免疫反應仍很強烈。另外ECM/Re在植入1個月後，其結構內新生血管密度與hemoglobin含量，皆明顯的比植入1星期後的量來得多。相對地，ECM/bFGF在植入1個月與1星期後的新生血管並沒有明顯的增加，而ECM/control內的血管增生情形並不顯著。此結果顯示了，Re在ECM內能夠持續有效的促進血管增生，而bFGF可能由於其穩定性不佳很快的失去活性，無法持續有效的促進ECM內的血管增生。
上述體外與體內實驗結果顯示，Rg1與Re皆為有效促進血管增生的新型生長因子，且可加速組織再生及修復的速率。未來我們可利用Rg1與Re親疏水性質的不同，分別應用於親水性與疏水性材料的包覆釋放。

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