title: pH-dependent hemolysis of biocompatible imidazole-grafted polyaspartamide derivatives.
abstract: A series of novel, pH-sensitive, endosomolytic polymers based on imidazole-grafted polyaspartamide were synthesized to characterize the pH-sensitive membrane fusion properties of red blood cells and their toxicity to L929 cells. All imidazole-containing polymers exhibited strong cationic characteristics under acidic conditions, as well as a high buffering effect in the pH range 5-7. In the presence of O-(2-aminoethyl)-O'-methylpolyethylene glycol and 1-(3-aminopropyl)imidazole-grafted polyaspartamide (MPEG/API-g-PASPAM) systems red blood cells agglutinated below pH 6.5 without any hemolytic effect. The octadecylamine, O-(2-aminoethyl)-O'-methylpolyethylene glycol and 1-(3-aminopropyl)imidazole-grafted polyaspartamide (C18/MPEG/API-g-PASPAM) systems, however, displayed considerable hemolytic behavior below pH 6.5, but no hemolysis occurred above this pH. It can be concluded from these results that not only the pH-sensitive imidazole group, but also the hydrophobic octadecyl chain plays a critical role in membrane fusion. The hypothetical mechanism of this fusion involves both ionic and hydrophobic interactions between the polymers and lipid bilayers.
authors.affiliation: Department of Chemical Engineering, Sungkyunkwan University, 300 Chunchun-dong, Jangan-gu, Suwon, Kyungki 440-746, Republic of Korea.
authors.forename: Kwangwon
authors.initials: K
authors.lastname: Seo
authors.forename: Dukjoon
authors.initials: D
authors.lastname: Kim
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry / Q000494:pharmacology*; D002478:Cells, Cultured; D003432:Cross-Linking Reagents / Q000737:chemistry; D006461:Hemolysis / Q000187:drug effects* / Q000502:physiology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007093:Imidazoles / Q000737:chemistry* / Q000494:pharmacology*; D008422:Materials Testing; D010455:Peptides / Q000737:chemistry* / Q000494:pharmacology*; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D007093:Imidazoles; D010455:Peptides; C017645:polyaspartate; C029899:imidazole