Copolymer polypeptide-based block

Fig. 24 Self-assembly of polypeptide-based block and graft copolymer mixtures. Reprinted with permission from [139]. Copyright 2012 American Chemical Society...

Carlsen A, Lecommandoux S (2009) Self-assembly of polypeptide-based block copolymer amphiphiles. Curr Opin Colloid Interface Sci 14 329-339... 

Gebhardt KE, Ahn S, Venkatachalam G, Savin DA (2008) Role of secondary structure changes on the morphology of polypeptide-based block copolymer vesicles. J Colloid Interface Sci 317 70-76... 

J. Rodriguez-Hernandez, E. Ibarboure, E. Papon, Surface segregation of polypeptide-based block copolymer micelles an approach to engineer nanostructured and stimuli responsive surfaces, European Polymer Journal 47 (2011) 2063-2068. 

Schlaad H, Smarsly B, Losik M (2004) The role of chain-length distribution in the formation of solid-state structures of polypeptide-based rod-coil block copolymers. Macromolecules 37 2210-2214... 

Osada, K. and Kataoka, K Drug and Gene Delivery Based on Supramolecular Assembly of PEG-Polypeptide Hybrid Block Copolymers. Vol. 202, pp. 113-154. 

Despite the drawbacks of this method, it has been used to prepare a tremendous number of polypeptide hybrid block copolymers (Table 1), and when carefully executed provides reasonably well-defined samples. Synthetic polymer domains have been prepared by addition polymerization of conventional vinyl monomers, such as styrene and butadiene, as well as by ringopening polymerization in the cases of ethylene oxide and e-caprolactone. The generality of this approach allows NCA polymerization off of virtually any primary amine functionality, which was exploited in the preparation of star block copolymers by polymerization of sarcosine NCA from an amine-terminated trimethyleneimine dendritic core [37]. In most examples, the polypeptide domain was based on derivatives of either lysine or glutamate, since these form a-helical polypeptides with good solubility characteristics. These residues are also desirable since, when deprotected, they give polypep-... 

Besides the polypeptide hybrid block copolymers described earlier, there exist a few examples of purely peptide-based amphiphiles and block/random copolymers (copolypeptides) (Fig. 10). In the latter case, both the core and corona of aggregates consist of a polypeptide. Any of the studies reported so far dealt with aggregation in aqueous media. 

The phase behaviour of biomimetic polypeptide-based copolymers in solution was described and discussed with respect to the occurrence of secondary structure effects. Evidently, incorporation of crystallisable polypeptide segments inside the core of an aggregate has impact on the curvature of the corecorona interface and promotes the formation of fibrils or vesicles or other flat superstructures. Spherical micelles are usually not observed. Copolymers with soluble polypeptide segments, on the other hand, seem to behave like conventional block copolymers. A pH-induced change of the conformation of coronal polypeptide chains only affects the size of aggregates but not their shape. The lyotropic phases of polypeptide copolymers indicate the existence of hierarchical superstructures with ordering in the length-scale of microns. 

The lattice model, as put forth by Flory [84, 85], has been proved successful in the treatments of the liquid crystallinity in polymeric systems, despite its artificiality. In our series of work, the lattice model has been extended to the treatment of biopolypeptide systems. The relationship between the polypeptide ordering nature and the LC phase structure is well established. Recently, by taking advantage of the lattice model, we formulated a lattice theory of polypeptide-based diblock copolymer in solution [86]. The polypeptide-based diblock copolymer exhibits lyotropic phases with lamellar, cylindrical, and spherical structures when the copolymer concentration is above a critical value. The tendency of the rodlike block (polypeptide block) to form orientational order plays an important role in the formation of lyotropic phases. This theory is applicable for examining the ordering nature of polypeptide blocks in polypeptide block copolymer solutions. More work on polypeptide ordering and microstructure based on the Flory lattice model is expected. 

Osada K, Kataoka K (2006) Drug and gene delivery based on supramolecular assembly of PEG-polypeptide hybrid block copolymers. Adv Polym Sci 202 113-153... 

Cai C, Zhu W, Chen T, Lin J, Tian X (2009) Synthesis and self-assembly behavior of amphiphilic polypeptide-based brush-coil block copolymers. J Polym Sci A Polym Chem 47 5967-5978... 

Different polypeptide-based rod-coil block copolymers have been synthesized by Sanchez-Ferrer and Mezzenga through the ring-opening polymerization of the BLG-NGA monomer using amino-terminated macroinitiators based on PPO. The number of rods attached to the polymer, the volume fraction of the rod polypeptidic block, and the degree of polymerization were varied systematically so that the physical behavior of these... 

We introduced a new synthetic route for well defined pure polypeptide based rod-coil block copolymers combining the controlled ring-opening polymerization of Wcarboxyanhydrides (NCA) with the con-... 

Losik M, Kubowicz S, Smarsly B, Schlaad H (2004) Solid-state stiucture of polypeptide-based rod-coil block copolymers Folding of helices. Eur Phys J E 15 407-411... 

Agut, W., Taton, D., andLecommandoux, S. (2007) A versatile synthetic approach to polypeptide based rod-coil block copolymers by click chemistry. Macromolecules, 40,5653-5661. 

Although, there are many reviews on linear diblock chimeras, only a very few have addressed the synthesis of polypeptide-based materials with different macromolecular architectures (Hadjichristidis et al., 2009 Deming, 2006 Deming, 2000). In this chapter our discussion on the synthesis of well-defined complex chimeras, including linear multiblock co/ terpolymer, as well as nonlinear copolymer chimeras (e.g. star, graft, block-graft, dendritic), will hopefully enrich the current literature on macromolecular chimeras. This chapter will not address the self-assembly of these complex chimeras since this issue is discussed in another chapter of this volume. 

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