© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. 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 emulsifiers, 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 1H NMR spectroscopy and dynamic light scattering, and the determination of the critical micelle concentration (cmc) is performed using pyrene fluorescence 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.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): KUK-F1-029-32
Acknowledgements: This publication is based on work supported by Award No. KUK-F1-029-32, made by King Abdullah University of Science and Technology (KAUST). Light-scattering experiments were possible through support of the Deutsche Forschungsgemeinschaft (INST 93/774-1 FUGG). The authors are grateful to Prof. Rainer Jordan (TU Dresden) for support and access to equipment. This work was supported by the Fonds der Chemischen Industrie and the Free State of Bavaria. The authors gratefully acknowledge financial support by the German Plastics Center SKZ and the Julius-Maximilians Universitat Wurzburg for start-up funding.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.