Coassembly\nof Charged Copolymer Amphiphiles Featuring\npH-Regulated Antifouling Properties

Understanding the formation of highly ordered structures\nthrough\nself-assembly is crucial for developing various biologically relevant\nsystems. A significant expansion in the development of self-assembly\nchemistry features stable coassembly formation using a mixture of\ntwo oppositely charged polymers. This study provides insightful findings\non the coassembly of hydrophobic coumarin-integrated cationic (<b>P1–P3</b>) and anionic (<b>P1′–P3′</b>) copolymers toward the formation of vesicles in aqueous medium at\npH 7.4, with a hydrodynamic diameter (<i>D</i><sub>h</sub>) of 160 ± 10 nm and electrically neutral zwitterionic surfaces,\nconfirmed by dynamic light scattering. Upon varying the solution pH,\nan intriguing charge switchable behavior (+ve → 0 →\n−ve) and a drastic morphological transition to spherical aggregates\nof the vesicles were noticed. At pH 7.4, these coassembled vesicles\npossess a neutral surface charge, empowering them to resist nonspecific\nprotein (pepsin and lysozyme) adsorption via electrostatic repulsion,\nas evidenced by size evolution and protein binding measurements. Additionally,\nthe bilayer membrane allows for the encapsulation of hydrophilic and\nhydrophobic guest molecules and their sustained release in the presence\nof 10 mM esterase; thus, this study demonstrates potential applications\nof coassembly to serve as a drug delivery vehicle.