| Summary: | 碩士 === 國立成功大學 === 化學工程學系 === 104 === In this study, the effects of bovine serum albumin (BSA) on the mixed Langmuir monolayer behavior of hexadecyltrimethylammonium-hexadecylsulfate (HTMA-HS), with dipalmitoyl phosphatidylethanolamine-polyethylene glycol 1000 (DPPE-PEG1000), 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE), and polyvinylpyrrolidone (PVP), respectively, were investigated by the Langmuir trough approach. Cyclic compression-expansion isotherms of the monolayers were examined to elucidate the induced removal characteristic of the molecules at the air/liquid interface. For mixed monolayers of HTMA-HS with adsorbed BSA at the cyclic interface, HTMA-HS would leave the interface with BSA during the interface compression stage, causing the loss of HTMA-HS at the interface. Comparing the results of mixed HTMA-HS/DPPE-PEG1000/BSA and HTMA-HS/DPPE/BSA monolayers, it is inferred that PEG chains were helpful in preventing the readsorption of BSA during the interface expansion stage. This property can be attributed to its segmental flexibility and its polar but uncharged chemical composition. The segmental flexibility results in high degree of steric exclusion at PEG-water interfaces, which in turn leads to protein resistance. The addition of hydrophilic polymer, PVP, could reduce the inhibition effect of BSA. This is because PVP could exert repulsive force on BSA when BSA approached the interface during the interface expansion stage.
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