Chitosan effects on monolayers of zwitterionic, anionic and a natural lipid extract from E. coli at physiological pH

Author(s)

Jochelavicius, Karen ^[1] ; Pereira, Andressa R. ^[1] ; Fiamingo, Anderson ^[1] ; Nobre, Thatyane M. ^[1] ; Campana-Filho, Sergio P. ^[2] ; Oliveira Jr, Osvaldo N.

Affiliation

^[1] Univ Sao Paulo, Sao Carlos Inst Phys, Sao Carlos, SP - Brazil

^[2] Univ Sao Paulo, Sao Carlos Inst Chem, Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: COLLOIDS AND SURFACES B-BIOINTERFACES; v. 209, n. 2 JAN 2022.
• Web of Science Citations: 0

Abstract

Langmuir monolayers are used to simulate the biological membrane environment, acting as a mimetic system of the outer or the inner membrane leaflet. Herein, we analyze the interaction of membrane models with a partially N-acetylated chitosan (Ch35%) possessing a quasi-ideal random pattern of acetylation, full water solubility up to pH approximate to 8.5 and unusually high weight average molecular weight. Lipid monolayers containing dipalmitoyl phosphatidyl choline (DPPC), dipalmitoyl phosphatidyl ethalonamine (DPPE), dipalmitoyl phosphatidyl glycerol (DPPG) or E. coli total lipid extract were spread onto subphases buffered at pH 4.5 or 7.4. The incorporation of Ch35% chitosan caused monolayer expansion and a general trend of decreasing monolayer rigidity with Ch35% concentration. Due to its relatively high content of N-acetylglucosamine (GlcNAc) units, Ch35% interactions with negatively charged monolayers and with E. coli extract were weaker than those involving zwitterionic monolayers or lipid rafts. While the smaller interaction with negatively charged lipids was unexpected, this finding can be attributed to the degree of acetylation (35%) which imparts a small number of charged groups for Ch35% to interact. Chitosan properties are therefore determinant for interactions with model cell membranes, which explains the variability in chitosan bactericide activity in the literature. This is the first study on the effects from chitosans on realistic models of bacterial membranes under physiological pH. (AU)

• FAPESP's process: 18/22214-6 - Towards a convergence of technologies: from sensing and biosensing to information visualization and machine learning for data analysis in clinical diagnosis
• Grantee: Osvaldo Novais de Oliveira Junior
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 18/00878-0 - Study of lipid rafts through the interaction between membrane models and chitosan and cholesterol oxidase
• Grantee: Andressa Ribeiro Pereira
• Support Opportunities: Scholarships in Brazil - Post-Doctoral