Self-Assembling Peptide—Polymer Nano-Objects via Polymerization-Induced Self-Assembly

Abstract

Self-assembling peptides (SAP) have been extensively studied for their ability to form nanoscale ordered structures driven by non-covalent molecular interactions. Meanwhile, polymerization-induced self-assembly (PISA) has been exploited as a facile and efficient way to produce various amphiphilic block copolymer nano-objects, whose self-assembly was governed predominantly by the interactions of the different blocks with the polymerization medium. In this work, we combined PISA with SAP to prepare novel peptide-polymer hybrid nano-objects, thus harnessing the advantages of PISA and the self-assembling driving force of SAP. A tripeptide methacrylamide derivative (MAm-Gly-Phe-Phe-NH2, denoted MAm-GFF where MAm means methacrylamide) was copolymerized with glycerol monomethacrylate (GMA) to produce P(GMA65-stat-(MAm-GFF)7) macro-chain transfer agent (macro-CTA) by Reversible addition-fragmentation chain transfer (RAFT) polymerization in DMF.This peptide-based macro-CTA was then successfully chain-extended with poly(2-hydroxypropyl methacrylate) (PHPMA) by aqueous dispersion PISA, forming P(GMA65-stat-(MAm-GFF)7)-b-PHPMA28 self-assembled objects. Fibrous structures were observed by TEM and Cryo-TEM in agreement with DDLS, SLS and SAXS experiments that also revealed long anisotropic morphologies. Such structures have not been reported previously for PISA-prepared nano-objects. This confirms the decisive influence of the GFF SAP on the self-assembly. In addition, annealing the PISA suspension at different temperatures led to a significant size decrease of the self-assembled objects and to a morphological transition caused by the thermo-sensitivity of both the core-forming PHPMA block and the stabilizing P(GMAstat-(MAm-GFF)) block.

Nonionic UCST–LCST Diblock Copolymers with Tunable Thermoresponsiveness Synthesized via PhotoRAFT Polymerization

“…Polymers with LCST transitions in water have been extensively studied as they can be applied for many applications, like the development of drug delivery, [ 7–9 ] gating membranes, [ 10–13 ] and polymeric thermometers. [ 14–16 ] Among the abundant choices for LCST polymers, poly[oligo(ethylene glycol) methacrylate]s (POEGMAs) with different lengths of side chains have some superior features.…”

Protein-, (Poly)peptide-, and Amino Acid-Based Nanostructures Prepared via Polymerization-Induced Self-Assembly

“…Such nanoparticles were subsequently used to engineer antimicrobial thin film membranes that successfully purified water containing Staphylococcus epidermidis bacteria. The same group later incorporated peptide-containing methacrylamide units (MAm-GFF) within a hydrophilic poly(glycerol monomethacrylate) (PGMA) corona-forming block to produce peptide-based P(GMA- stat -(MAm-GFF))- b -PHPMA block copolymer assemblies in situ via aqueous RAFT-mediated dispersion PISA [ 77 ]. In this case, dendritic, flower-like fibers were formed in a self-assembly behavior that was predominantly governed by non-covalent interactions between peptide-decorated monomeric units within coronal chains ( Figure 4 A), similar to that observed in self-assembling peptides (SAPs) [ 78 ].…”

Polymerizations by RAFT: Developments of the Technique and Its Application in the Synthesis of Tailored (Co)polymers

“…For example, hybrid polymer–inorganic nanoparticles could be prepared through the interaction between β‐cyclodextrin decorated nanoparticles prepared via PISA and gold nanoparticles decorated with adamantine. [ 89 ] Other recent examples of PISA prepared particles with potential bioapplication are peptide‐, [ 90–92 ] deoxyribonucleic acid‐, [ 93 ] nitrilotriacetic acid‐, [ 94 ] and dextran‐decorated particles. [ 95 ]…”

“…The resulting morphologies were mainly long rigid rods and branched, leaf‐like structures that are believed to be formed due to the presence of the tripeptide sequences bale to form H‐bonding and π–π stacking. [ 91,92 ]…”