@phdthesis{Vacogne2016,
  author    = {Vacogne, Charlotte D.},
  title     = {New synthetic routes towards well-defined polypeptides, morphologies and hydrogels},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-396366},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xii, 175},
  year      = {2016},
  abstract  = {Proteins are natural polypeptides produced by cells; they can be found in both animals and plants, and possess a variety of functions. One of these functions is to provide structural support to the surrounding cells and tissues. For example, collagen (which is found in skin, cartilage, tendons and bones) and keratin (which is found in hair and nails) are structural proteins. When a tissue is damaged, however, the supporting matrix formed by structural proteins cannot always spontaneously regenerate. Tailor-made synthetic polypeptides can be used to help heal and restore tissue formation. Synthetic polypeptides are typically synthesized by the so-called ring opening polymerization (ROP) of α-amino acid N-carboxyanhydrides (NCA). Such synthetic polypeptides are generally non-sequence-controlled and thus less complex than proteins. As such, synthetic polypeptides are rarely as efficient as proteins in their ability to self-assemble and form hierarchical or structural supramolecular assemblies in water, and thus, often require rational designing. In this doctoral work, two types of amino acids, γ-benzyl-L/D-glutamate (BLG / BDG) and allylglycine (AG), were selected to synthesize a series of (co)polypeptides of different compositions and molar masses. A new and versatile synthetic route to prepare polypeptides was developed, and its mechanism and kinetics were investigated. The polypeptide properties were thoroughly studied and new materials were developed from them. In particular, these polypeptides were able to aggregate (or self-assemble) in solution into microscopic fibres, very similar to those formed by collagen. By doing so, they formed robust physical networks and organogels which could be processed into high water-content, pH-responsive hydrogels. Particles with highly regular and chiral spiral morphologies were also obtained by emulsifying these polypeptides. Such polypeptides and the materials derived from them are, therefore, promising candidates for biomedical applications.},
  language  = {en}
}
@misc{VacogneBrosnanMasicetal.2015,
  author    = {Vacogne, Charlotte D. and Brosnan, Sarah M. and Masic, Admir and Schlaad, Helmut},
  title     = {Fibrillar gels via the self-assembly of poly(L-glutamate)-based statistical copolymers},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-102289},
  pages     = {5040 -- 5052},
  year      = {2015},
  abstract  = {Polypeptides having secondary structures often undergo self-assembly which can extend over multiple length scales. Poly(γ-benzyl-L-glutamate) (PBLG), for example, folds into α-helices and forms physical organogels, whereas poly(L-glutamic acid) (PLGA at acidic pH) or poly(L-glutamate) (PLG at neutral/basic pH) do not form hydrogels. We explored the gelation of modified PBLG and investigated the deprotection of the carboxylic acid moieties in such gels to yield unique hydrogels. This was accomplished through photo-crosslinking gelation of poly(γ-benzyl-L-glutamate-co-allylglycine) statistical copolymers in toluene, tetrahydrofuran, and 1,4-dioxane. Unlike most polymer-based chemical gels, our gels were prepared from dilute solutions (<20 g L-1, i.e., <2\% w/v) of low molar mass polymers. Despite such low concentrations and molar masses, our dioxane gels showed high mechanical stability and little shrinkage; remarkably, they also exhibited a porous fibrillar network. Deprotection of the carboxylic acid moieties in dioxane gels yielded pH responsive and highly absorbent PLGA/PLG-based hydrogels (swelling ratio of up to 87), while preserving the network structure, which is an unprecedented feature in the context of crosslinked PLGA gels. These outstanding properties are highly attractive for biomedical materials.},
  language  = {en}
}
@misc{VacogneSchlaad2015,
  author    = {Vacogne, Charlotte D. and Schlaad, Helmut},
  title     = {Primary ammonium/tertiary amine-mediated controlled ring opening polymerisation of amino acid N-carboxyanhydrides},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-102718},
  pages     = {15645 -- 15648},
  year      = {2015},
  abstract  = {Stable commercial primary ammonium chlorides were combined with tertiary amines to initiate the controlled ring opening polymerisation of amino acid N-carboxyanhydrides to yield polypeptides with defined end group structure, predetermined molar mass and narrow molar mass distribution.},
  language  = {en}
}