中孔洞二氧化矽材料附載生物模擬超氧歧化酵素

Abstract

超氧歧化酵素(superoxide dismutase)普遍存在人體和動、植物細胞。一般生理上會引起ROS(Reactive Oxygen Species) Stress，進而傷害細胞、破壞DNA，甚至造成細胞凋亡(Apoptosis)，在此超氧歧化酵素扮演著很重要的清除超氧離子的抗氧化作用。經由模擬超氧歧化酵素的活性中心結構，合成了一個與它相近的生物模擬CuZn 金屬錯合物(Biomimic complex)，可以從UV, IR Spectrum 觀察出它的結構特徵，另外也由一種間接的競爭方式測出它的活性表現IC50 約為55 μM。In vitro 方面，藉由將這個生物模擬CuZn 金屬錯合物(Biomimic complex)附載到各種不同的中孔洞二氧化矽材料(Al-MCM41,48, MAS9, MSN…等)，研究其附載上去之後的活性、穩定性表現，進一步再比較使用共價鍵和離子鍵等不同的修飾方法，在活性上的差異性，發現部份離子鍵的修飾法活性相對較高，甚至達到約3 倍的提昇效果。n vivo方面，藉由本實驗室之前所開發出來的修飾有FITC螢光物中孔洞奈米粒子(MSN-FITC)，之前已確定它具有進入細胞的能力，是將生物模擬CuZn金屬錯合物(Biomimic complex)修飾上去，進一步去研究它們在細胞中的毒性測試，活性表現、降低老鼠肝指數等方向。

Superoxide dismutases (SODs) are found in prokaryotes,itochondria iron and plants, and the copper -zinc SODs are most frequent in eukaryotic cells. Cells are normally able to prevent DNA damage and apoptosis by defending themselves against reactive oxygen species(ROS) damage through the use of enzymes such as superoxide dismutases and catalases. We have synthesized a biomimic complex of CuZnSOD by imitating of its structure of active site. The spectrum of UV and IR could provide the characteristics of this mimic complex, and activity assay counld be conducted via an indirect competition method. The IC 50 of the mimic complex is about 55μM. Immobilizing the mimic complex into NaY and mesoporous materials through electronic and covalent bond would result in different activity and stability in vitro. We found that materials modified with electronic bond would generally raise its activity due to their larger freedom than those modified with covalent bond. In vivo, MSN -FITC had been proved its cell permeability. Modifying MSN -FITC with mimic complex could enter cells to eliminate superoxide and to lower the live function index of male mice stressed by acetaminophen.