Block copolypeptides, synthetic

Deming T.J., Methodologies for preparation of synthetic block copolypeptides Materials with future promise in dmg dehvery, Adv. Drug Deliv. Rev., 54, 1145, 2002. 

Living NCA polymerizations of a wide variety of monomers have also been initiated with transition metal catalysts, allowing the preparation of proteins and block copolypeptide-sin high yield with low polydispersity. NCA catalysts have also been employed to produce low-polydispersity protein-synthetic polymer hybrid materials. Using a bifunctional initiator in nickel-mediated NCA polymerization followed by ATRP, poly(Y-benzyl-L-glutamate-l7-methyl methacrylate) (PBLG-b-PMMA) was prepared with polydispersity in the range of 1.2-1.4. ... 

Bellomo and co-workers prepared a new type of synthetic vesicle with a high degree of architectural control made of amphiphilic block copolypeptides (Bellomo et al., 2004). The hydrophUic block was made of lysine, augmented with a few water-soluble ethylene glycol units, and the hydro-phobic block was constituted by leucine peptide. The synthetic polymer forms a supramolecular structure highly sensitive to environmental signals... 

The synthesis of polypeptides by ring-opening polymerization is an area that has been under study for more than five decades. Initially, this field suffered from limitations that necessitated excessive sample purification and fractionation to obtain well-defined polypeptides. Over the last 15 years, vast improvements in NCA polymerizations now allow the synthesis of a variety of block copolypeptides of controlled dimensions (molecular weight, sequence, composition, and molecular weight distribution). Many different block copolypeptides have now been prepared and used to form self-assembled structures with promising properties. The ability to easily adjust chain conformation and functionality in polypeptides, in combination with advanced synthetic methods that enable preparation of complex sequences, has opened up a new, promising field of materials with a wide range of tunable properties. 

Recently, synthetic or natural polypeptides have been created or modified to serve as sihca condensation templates. Examples of these include the poly(amino acids) [79], the diatom-derived R5-peptide [66], chimeric polypeptides [64, 67], block copolypeptides [71, 72, 75, 80], lanreotide [63] and even the naturally occurring protamine [65]. These polypeptides have been used to produce a variety of sihca shapes and sizes, which can be tuned to perform a variety of applications, including transport and the separation of encapsulated materials [62], or potentially for dmg dehvery [73]. 

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