Polyelectrolytes, peptides

Pu, K.-Y. Li, K. Liu, B. Multicolor conjugate polyelectrolyte/peptide complexes as self-assembled nanoparticles for receptor-targeted cellular imaging. Chem. Mater. 2010, 24, 6736-6741. 

As for polyelectrolytes, peptide binding to phospholipid membranes and surfaces is expected to decrease with decreasing peptide length as a result of the increased entropy penalty (per amino acid) on adsorption. For peptides displaying adsorption-induced conformational changes, there is also a decreased tendency to form ordered... 

The structures of these ylide polymers were determined and confirmed by IR and NMR spectra. These were the first stable sulfonium ylide polymers reported in the literature. They are very important for such industrial uses as ion-exchange resins, polymer supports, peptide synthesis, polymeric reagent, and polyelectrolytes. Also in 1977, Hass and Moreau [60] found that when poly(4-vinylpyridine) was quaternized with bromomalonamide, two polymeric quaternary salts resulted. These polyelectrolyte products were subjected to thermal decyana-tion at 7200°C to give isocyanic acid or its isomer, cyanic acid. The addition of base to the solution of polyelectro-lyte in water gave a yellow polymeric ylide. 

A host of bioadhesive controlled release systems have been proposed in recent years. Among the most commonly studied applications of bioadhesive materials is the area of buccal controlled delivery [408], The buccal delivery of small peptides from bioadhesive polymers was studied by Bodde and coworkers [409], and a wide range of compositions based on poly(butyl acrylate) and/or poly(acrylic acid) gave satisfactory performance. Bioadhesive poly(acrylic add)-based formulations have also been used for oral applications [402,410] for the sustained delivery of chlorothiazide [410] and for a thin bioadhesive patch for treatment of gingivitis and periodontal disease [411]. Other bioadhesive applications of polyelectrolytes include materials for ophthalmic vehicles [412,413], and systems for oral [410,414,415-419], rectal [420,421] vaginal [422] and nasal [423] drug delivery. 

Chluba J, Voegel J-C, Decher G et al (2001) Peptide hormone covalently bound to polyelectrolytes and embedded into multilayer architectures conserving full biological activity. Biomacromolecules 2 800-805... 

Guyomard A, De E, Jouenne T et al. (2008) Incorporation of a hydrophobic antibacterial peptide into amphiphilic polyelectrolyte multilayers a bioinspired approach to prepare biocidal thin coatings. Adv Funct Mater 18 758-765... 

Aggeli, A., Bell, M., Boden, N., Carrick L.M., and Strong A.E. "Self-assembling peptide polyelectrolyte beta-sheet complexes form nematic hydrogels". Angew. Chem. Int. Ed. 42(45), 5603-5606 (2003a). 

This entire subject is a very difficult one because of the complex substances the human body contains. The peptides have been attacked via study of simple model compounds, and the techniques of polymer science are being used. The same approach may be useful for other types of compounds now that synthetic polyribonucleic acids and polyelectrolytes are being made. The latter include charged side chains and thus resemble biocolloidal molecules (1086). 

As the term polyelectrolyte can also be extended to encompass natural biopolymers, which contain ionizable groups such as peptides, proteins, and DNA, it is perhaps not surprising that synthetic polyelectrolytes are often used as simple models for more complex biological systems. Indeed, many of the photophyscial techniques discussed in this chapter were developed by biologists and biophysicists interested in the conformational behavior and interactions of biopolymers [1]. 

The polyelectrolytic properties of chitosan may further be used to form complexes with DNA plasmid, which are protected from enzymatic degra-dation. 5 MacLaughlin et al. foxmd that plasmid-chitosan complexes with a 1 2 ionic charge ratio were stable in vitro Furthermore, they foxmd that the chitosan complexes, when containing the endosomolytic peptide GM225.1, led to transgene expression in small intestine of rabbits, while naked plasmids yielded no expression. 

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