微生物在生活中被廣泛應用，例如汙水處理使用各類微生物來分解有機廢物或是重金屬，利用厭氧菌來製造醇類，醫學上也有利用細菌進行治療的細菌癌症療法。但不可避免的在作用環境中總有不利於微生物生存的條件存在，像是水中可能含有抗菌劑、厭氧菌作用環境無法完全阻隔氧氣、病人體內的溶菌?和抗生素等，都會減弱微生物的活性及存活能力。因此科學家便致力於研究有機或無機材料結合生物體的生物複合材料，來增強生物細胞對於環境壓力的適應性。 金屬有機骨架材料 (MOFs)，可藉由調整金屬離子與有機配體，根據需求調整其孔洞性質、比表面積、化學穩定性等，具有相當的多樣性，因此近期常被應用於與生物系統結合之研究。 本研究藉由將類沸石咪唑骨架材料-8 (ZIF-8) 合成於大腸桿菌表面形成塗層 (E. coli?ZIF-8)，並於培養環境中添加抗生素來檢驗文獻中曾提到ZIF-8薄膜可能存有縫隙，進而使抗生素經由縫隙接觸大腸桿菌對其造成傷害的 現象，並利用本實驗室於2015年發表於JACS利用類沸石咪唑骨架材料-90 (ZIF-90) 封裝酵素之技術，形成微米級ZIF-90封裝大腸桿菌 (E. coli@ZIF-90) 來解決縫隙造成之問題，使得經歷培養於含抗生素的環境後，移除材料的大腸桿菌依然可以回復生長。經由量測反應物和反應環境之zeta電位來嘗試解釋造成兩者差異之原因，並研究ZIF-90封裝之大腸桿菌對於生物免疫系統之誘發與否，對於未來應用於癌症治療之可行性以及希望能將此研究成果進一步應用於真核生物-酵母菌上，以期未來能在生物複合材料的種類拓展上有更大的突破。 ;Microorganisms are widely used in life. For example, decomposing organic waste in sewage, producing alcohol by anaerobic fermentation, besides, bacteria can also be used in cancer treatment called “bacteria cancer therapy”. However, there are always some factors which will threaten their survival. Antiseptics exist in water, oxygen exist in the media of anaerobic bacteria, lysozyme and antibiotics in patients. These conditions all make microorganisms deactivate. Therefore, scientists research on combining organic or inorganic materials with cells in order to enhance their adaptability toward environmental stress. Metal organic frameworks (MOFs) have variable pore properties, specific surface area, chemical stability. Scientists can adjust these properties by changing the precursors to fit their purpose. Therefore, the development of biocomposites by combinig Metal-organic frameworks and living systems is rapidly emerging. In this study, Escherichia coli (E. coli) cell was encapsulated into single crystal zeolitic imidazolate framework-90 (ZIF-90). Being totally encapsulated by ZIF-90, E. coli gains the ability to survive the treatment of antibiotics. E. coli can still regrowth after removing the material. On the other hand, E. coli coated with nano-size ZIF-8 particles was damaged by antibiotics due to the defects of the coating layer. We also noticed the zeta potential differences between different synthetic conditions impact on the crystalline morphology. By studying whether the encapsulated E. coli will trigger the immunoreaction or not, we saw the feasibility of applying it to cancer therapy and hope we can apply this technic in encapsulating eukaryote like yeast in the future.
