pH-dependent hemolysis of biocompatible imidazole-grafted polyaspartamide derivatives

✍ Scribed by Kwangwon Seo; Dukjoon Kim

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 744 KB
• Volume: 6
• Category: Article
• ISSN: 1742-7061
• DOI: 10.1016/j.actbio.2009.11.016

✦ Synopsis

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.