Self‐Assembly of Amphiphilic Block Copolypeptoids with C₂‐C₅ Side Chains in Aqueous Solution

Abstract

Nowadays, amphiphilic molecules play an important role in our life. In medical applications, amphiphilic block copolymers have attracted much attention as excipients in drug delivery systems. Here, the polymers are used as emulsifi ers, micelles, or polymersomes with a hydrophilic corona block and a hydrophobic core or membrane. The aggregation behavior in aqueous solutions of a series of different amphiphilic block copolypeptoids comprising polysarcosine as a hydrophilic part is here reported. The formation of aggregates is investigated with 1 H NMR spectroscopy and dynamic light scattering, and the determination of the critical micelle concentration (cmc) is performed using pyrene fl uorescence spectroscopy. For the different block copolypeptoids cmc values ranging from 0.6 × 10 −6 M to 0.1 × 10 −3 M are found. The tendency to form micelles increases with increasing hydrophobicity at the nitrogen side chain in the hydrophobic moiety. Furthermore, in the case of the same hydrophobic side chain, a decreasing hydrophilic/lipophilic balance leads to the formation of larger aggregates. The aggregates formed in the buffer are able to solubilize the hydrophobic model compounds Reichardt's dye and pyrene, and exhibit versatile microenvironments. Final investigations about the cytotoxicity reveal that the block copolypeptoids are well tolerated by mammalian cells up to high concentrations.

Polypeptoids with tunable cloud point temperatures synthesized from N-substituted glycine N-thiocarboxyanhydrides

“…11). 65 The block copolypeptoids probably performed better because of a stealth effect from a PSar shell around the stable micelles, preventing the exposure of the hydrophobic moieties. At low concentrations (0.05, 0.5 and 1 mg mL −1 ), all the samples are dissolved in water at 37°C and exhibit non-cytotoxicity, as with PSar.…”

Thermoreversible and Injectable ABC Polypeptoid Hydrogels: Controlling the Hydrogel Properties through Molecular Design

“…This gives rise to excellent thermal processability, good solubility in many common solvents, as well as enhanced protease stability. 44,45 In addition, polypeptoids exhibit good cytocompatibility 47,48 and can be degraded under oxidative conditions that mimics tissue inflammation. 50 These combined attributes make polypeptoids an attractive material of biomedical and biotechnological relevance.…”

“…45,49–53 Recent development in the organo-mediated controlled polymerization has enabled access to a suite of well-defined polypeptoid homo and block copolymers. 44,46,48,54,55 Amphiphilic block copolymers comprised of hydrophilic polypeptoid segments have also been investigated for biomedical applications such as drug carriers. 56–58 …”

Poly(α‐Peptoid)s Revisited: Synthesis, Properties, and Use as Biomaterial

“…Luxenhofer and coworkers recently studied a series of such amphiphilic polypeptoids based on polysarcosine and hydrophobic polypeptoids with aliphatic side chains ranging from propyl to pentyl. In all cases, no cytotoxicity was observed at the solubility limit of the polymers …”