本文選題：聚酰胺-胺 + 脂質(zhì)體　； 參考：《天津大學》2008年碩士論文

【摘要】： 聚酰胺-胺(PAMAM,polyamidoamine)以其獨有的分子結(jié)構(gòu)和物理特性,能夠通過靜電疏水等作用與DNA緊密結(jié)合,并將其縮聚,保護DNA不被降解,是近年來廣泛使用的非病毒基因治療載體。但是相比病毒載體,PAMAM的轉(zhuǎn)染效率仍然很低,這是由于它在轉(zhuǎn)染過程中存在多個屏障。對于PAMAM/DNA復合物與細胞結(jié)合并進入細胞的具體機制的理解,克服PAMAM轉(zhuǎn)染過程的細胞膜屏障,將有助于我們找到提高PAMAM轉(zhuǎn)染效率方法。 本文采用卵磷脂脂質(zhì)體模擬細胞膜骨架,并在其中加入膽固醇單組分,通過等溫微量量熱法,Zeta電勢和透射電子顯微鏡,對PAMAM/DNA復合物與脂質(zhì)體的相互作用進行考察,探索PAMAM/DNA復合物與脂質(zhì)體膜的作用機制,以及膽固醇在其中所起到的作用。 熱力學研究表示,對于含有和不含有膽固醇的脂質(zhì)體,PAMAM/DNA復合物主要通過靜電作用與其表面結(jié)合,反應由焓驅(qū)動,膽固醇的加入將使結(jié)合在表面的PAMAM/DNA復合物能夠嵌入脂雙層中,從而引起焓變、熵變的增大,甚至出現(xiàn)聚集的吸熱過程。PAMAM/DNA復合物的電荷比大于1時,脂質(zhì)體的負電勢隨著PAMAM/DNA復合物的加入而減小,說明兩者通過靜電作用結(jié)合,膽固醇在靜電結(jié)合的過程中沒有作用。通過電鏡觀察,對于不加膽固醇的脂質(zhì)體,PAMAM/DNA復合物結(jié)合在脂質(zhì)體表面,可以看到兩球結(jié)合的狀態(tài),對于加入膽固醇的脂質(zhì)體,PAMAM/DNA復合物進入脂質(zhì)體內(nèi)部,脂質(zhì)體粒徑增大,仍為球狀。各種檢測均表明PAMAM/DNA復合物通過靜電作用結(jié)合在表面后,通過膽固醇的作用進入細胞膜。
[Abstract]:Polyamidoamine (PAMAM) is a widely used non-viral gene therapy vector in recent years, because of its unique molecular structure and physical properties, it can be tightly combined with DNA by electrostatic hydrophobicity and condensed to protect DNA from degradation. However, the transfection efficiency of PAMAM is still very low compared with that of virus vector pama, which is due to the existence of multiple barriers during the transfection process. Understanding the specific mechanism of PAMAM / DNA complex binding to cells and entering cells, overcoming the membrane barrier during PamAm transfection will help us to find a way to improve the transfection efficiency of PamAm. In this paper, lecithin liposome was used to simulate the membrane skeleton. Cholesterol monocomponent was added to it. The interaction between PamAm / DNA complex and liposome was investigated by means of isothermal microcalorimetry Zeta potential and transmission electron microscope, and the mechanism of the interaction between PamAm / DNA complex and liposome membrane was explored. Thermodynamic studies show that for liposomes containing and without cholesterol, the pama / DNA complex is mainly bound to its surface by electrostatic interaction, and the reaction is driven by enthalpy. When cholesterol is added, the PAMAM- / DNA complex that binds to the surface can be embedded in the lipid bilayer, resulting in enthalpy changes, entropy changes, and even the aggregation of endothermic processes. The charge ratio of PAMAM- / DNA complexes is greater than 1. The negative potential of liposome decreases with the addition of PamAm / DNA complex, indicating that cholesterol has no effect on electrostatic binding. The observation of electron microscope showed that when the liposome without cholesterol was bound to the surface of the liposome, it could be seen that the two spheres were bound. For the liposome containing cholesterol, the pama / DNA complex entered into the liposome, and the diameter of the liposome increased. Still spherical. The results showed that the PAMAM / DNA complex was bound to the surface by electrostatic interaction and entered the cell membrane by cholesterol.
【學位授予單位】：天津大學
【學位級別】：碩士
【學位授予年份】：2008
【分類號】：R346

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本文編號：2002410