Modulation of Double Zwitterionic Block Copolymer Aggregates by Zwitterion-Specific Interactions

Abstract

Transformable double hydrophilic block copolymer assemblies are valid as a biocompatible smart macromolecular system. The molecular mechanisms in the spontaneous assembly of double zwitterionic diblock copolymers composed of a poly-(carboxybetaine methacrylate) (PCB2) and a poly(sulfobetaine methacrylate) (PSB4) chains (PCB2-b-PSB4) were investigated by the modulation of the aggregates in response to nondetergent zwitterions. The PCB2-b-PSB4 diblock copolymers with a high degree of polymerization PSB4 block produced aggregates in saltfree water through "zwitterion-specific" interactions. The PCB2-b-PSB4 aggregates were dissociated by the addition of nondetergent sulfobetaine (SB4) and carboxybetaine (CB2) molecules, while the aggregates showed different aggregation modulation processes for SB4 and CB2. Zwitterions with different charged groups from SB4 and CB2, glycine and taurine, hardly disrupted the PCB2-b-PSB4 aggregates. The PCB2-b-PSB4 aggregate modulation efficiency of SBs associated with the intercharge hydrocarbon spacer length (CSL) rather than the symmetry with the SB in the PSB chain. These zwitterion-specific modulation behaviors were rationalized based on the nature of zwitterions including partial charge density, dipole moment, and hydrophobic interactions depending on the charged groups and CSL.

Multihydrogen Bond Modulated Polyzwitterionic Removable Adhesive Hydrogel with Antibacterial and Hemostatic Function for Wound Healing

“…In this research, a novel block copolymer-based hydrogel with a triple hydrogen bond building unit, referred to as LST zwitterionic hydrogels, was prepared using the reversible addition- fragmentation chain transfer (RAFT) polymerization method. The cohesive interaction force within the LST zwitterionic hydrogels chains could be attributed to the balanced charge density and strong hydrogen bonding Figure a,b illustrated the synthetic route, chemical structure, and application of the LST zwitterionic hydrogels in the wound healing pathway and Figure S1 showed the FT-IR spectrum of LST zwitterionic hydrogels.…”

“…The cohesive interaction force within the LST zwitterionic hydrogels chains could be attributed to the balanced charge density and strong hydrogen bonding. 24 Figure 1a,b illustrated the synthetic route, chemical structure, and application of the LST zwitterionic hydrogels in the wound healing pathway and Figure S1 showed the FT-IR spectrum of LST zwitterionic hydrogels. The peak observed at 1639 cm −1 was related to the stretching vibrations of the C� O group in the amide.…”

“…This layer prevents protein adsorption, resulting in excellent antifouling and antibacterial capabilities. , Additionally, the dipole–dipole or ion–dipole interaction occurring between the zwitterionic polymers endow good mechanical properties and adhesion ability to the hydrogels . Moreover, polyzwitterionic hydrogels generally display prominent biocompatibility owing to the neutral net charge and intrinsic hydrogen bond networks generated by the hydrated water in them. − …”

Cononsolvency-Induced Microphase Separation of Double Hydrophilic Poly(2-ethyl-2-oxazoline)–Polycarboxybetaine Diblock Copolymers in Water–Ethanol Mixtures

“…DHBC assemblies can offer biocompatibility, permeability for hydrophilic substances, and degradability compared to the assemblies of amphiphilic block copolymers . We reported a new type of DHBCs composed of two distinct zwitterionic polymers of poly­(carboxybetaine methacrylate) (PCB2) and poly­(sulfobetaine methacrylate) (PSB4). – The double zwitterionic block copolymers produced well-ordered mesoscale lattice structures in water through microphase separation while exhibiting morphology transition depending on the polymer concentration owing to selective water partitioning due to the difference in the water affinity of individual blocks. The microphase separation of concentrated block copolymer solutions and their concentration-dependent morphology transition using selective solvents have been extensively studied. – However, for aqueous solutions, these studies remained limited to Pluronic block copolymers comprising PEO and poly­(propylene oxide); thus, studying the microphase separation and morphology transition of zwitterionic polymer systems may offer a unique material class for biologically relevant applications.…”

Phase Behavior of Double Zwitterionic Block Copolymers in Water: Morphology Transition through Concentration Dependent Selectivity of Water Partitioning

“…This copolymer can be regarded as a new type of double hydrophilic block copolymer composed of polyzwitterions that is valid for biomedical platforms. [28] The phase behavior of the PCB2 n -b-PSB4 m should be dominated by zwitterion-specific interactions and selective water partitioning, [27,29] but full details have not yet been elucidated.…”