摘要
Liposomes were prepared from mixtures of egg-PC, cholesterols and distearoyl-phosphatidyl-ethanolamine covalently attached poly-ethylene glycol (PEG) with a molecular of weight 2000 (DSPE-PEG2000). In this work examines how PEG2000-grafted lipids affect the surface properties of the egg phosphatidylcholine (egg-PC) liposomal bilayer membrane through zeta potential and interaction potential measurements using microcalorimetry. Experimental results demonstrate that the absolute value of the zeta potential of PEG2000-grafted PC liposomes decreased from -19 to -8 mV when increasing DSPE-PEG2000 from 0 to 7 mol fraction, and the repulsive interaction potential of PEG2000-grafted PC liposomes decreased compared with those liposomes without PEG-grafting. However, the phenomenon of fusion between the liposomes incorporated with PEG-grafted PC was reduced. In brief, this result of fusion is contrary to the expectation of the interaction potential measurement; therefore, we believe that the steric hindrance of the grafted PEG2000 molecules on the liposomal surface contribute to a major imposition on the approach between liposomal surface and the formation of inverted micelles which are suggested as the necessary steps of liposome fusion.
原文 | ???core.languages.en_GB??? |
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頁(從 - 到) | 227-234 |
頁數 | 8 |
期刊 | Colloids and Surfaces A: Physicochemical and Engineering Aspects |
卷 | 212 |
發行號 | 2-3 |
DOIs | |
出版狀態 | 已出版 - 23 1月 2003 |