膽固醇型液晶生物高分子的排列及自我重組過程之探討
Construction of Cholesteric Liquid Crystal Biopolymers and Self-assembly Process
中文摘要
蟹殼上之殼糖晶型結構、為生物型液晶之最佳研究材料。因具有規則的排列角度 並可於電子顯微鏡下觀察。本研究環繞殼糖為主軸、此種具有高分子特質之天然 生物醫學材料；藉由蟹殼、烏賊軟骨、靈芝這三種樣品為實驗標的，期望在穿透 式電子顯微鏡（TEM）底下搜尋膽酯醇型液晶相（cholesteric liquid
crystal）的存在位置與構型。將蟹殼（crab）以 2N NaOH 去蛋白、2N HCl 脫 鈣、冷凍乾燥脫水、EPON812 平板包埋等程序處理後，於 TEM 超薄切片
（80nm）下證實 chitin cholesteric liquid crystal texture 的存在
（Arced pattern of fingerprint）。後期將純化後之殼糖以 3N HCl；以及不 同濃度之NaOH， 104°C 煮沸回流約 1~6 小時，離心稀釋及透析後將酸移除，
並以超音波震盪後，使得降解過後之殼糖分子轉變為凝膠狀懸浮液，濃縮至一 定濃度後產生分層現象，其分子具有類似節肢動物中殼糖微纖維的排列特質。簡 言之，本研究的主要目的為搜尋膽酯醇型液晶並探討生体高分子液晶自我重組 的特點。
英文摘要
The chitin crystalline architecture on crabs were by far the most suitable
biomaterials for searching in liquid crystals. Owing to its regularly orientations and could be observed under transmission electron microscopy. The work here aims to chitin which is the biopolymers in nature, together with crabs, squid bone, and ganoderma residue as our targets for experiments. We try to find out the position and arrangement of chloesteric liquid crystal under transmission electron
microscopy. First, the crab was treated by 2N NaOH to hydrolyze the protein, dissolved the mineral phase in 2N HCl, dehydrated, embedded and cured in Epon812, the arced fingerprint pattern in chitin thus could be viewed via microtone ultracut (80nm). Microfibrillar fragments of purified crab chitin were prepared by hydrolysis in 3 M HCl at its boilong point (104°C), together with NaOH at various concentration. After discarding the acid by centrifugal washing and dialysis, an ultrasound treatment converts the residual product to a colloidal suspension stabilized by NH3+ charges. When dehydrated to a critical
concentration, spontaneous formation of a two-phase equilibrium system occurs.
The upper phase (lower concentration) is isotropic and the lower phase is
anisotropic. The latter displays chiral nematic order and dries to a solid film which mimics the helicoid organization characteristic of the chitin microfibrils in the
cuticle of arthopods.
