Polyelectrolytes, dendritic

Analysis by XPS after incorporation of the linear or dendritic cationic polymers showed an increase in the atom % N consistent with incorporation of an N-rich polycation. The polyvalent interactions between the cationic polyelectrolytes and the poly(sodium acrylate)graftson PE were stable to Soxhlet extraction with 95% ethanol, repeated acid/base treatment, and soaking or sonication in isopropanol and THE However, in these cases, simple acid treatment did not release the cationic polymer as was the case with PAA/Au grafts even though grafting in both cases was reportedly ionic and not covalent. 

Lin Y, Liao Q, Jin X. Molecular dynamics simulations of dendritic polyelectrolytes with flexible spacers in salt free solution. J Phys Chem B 2007 111 5819-5828. 

Ramzi, A. Scherrenberg, R. Joosten, J. Lemstra, P. Mortensen, K. Structure-property relations in dendritic polyelectrolyte solutions at different ionic strength. Macromolecules 2002, 35, 827-833. 

Q. Sun, M.-C. Park, and Y. Deng, Dendritic superstructure formation of polyanihne prepared using a water-soluble polyelectrolyte copolymer as the support matrix. Mater. Lett., 61, 3052-3055 (2007). 

Zhang et al. used polyelectrolyte-modified electrode to prepare gold clusters with dendritic structures (Fig. 3) [30]. They modified ITO electrode with six bilayers... 

Figure 3. SEM images of dendritic gold clusters formed on an ITO electrode modified with a polyelectrolyte multilayer by electrochemical deposition. Reproduced with permission from [30]. Copyright 2004 American Chemical Society.

Chojnowski, J. Fortuniak, W. Scibiorek, M. Rozga-Wijas, K. Grzelka, A. Mizerska, U., 3-Chloropropyl Functionalized Dendrigraft Polysiloxanes and Dendritic Polyelectrolytes. Macromolecules 2007, 40, 9339-9347. 

Keywords Brain Cylindrical brush polymer Dendritic and protein polyelectrolytes Endothelial ceU Flow cytometry Gene transfer Polycafirai Transfecticai... 

Exploring Cell Interactions of Dendritic and Protein Polyelectrolytes... 

In this chapter, the design of stmcturally defined dendritic and protein-based polyelectrolyte nanocarriers is presented and the impact of their macromolecular architectures and the presence of multiple charges and charge densities on cellular uptake, trafficking, and cell toxicity is discussed. 

Fig. 2 Dendritic polyelectrolyte interaction with (a) DNA and (b) the ECM (Vkg-GFP stands for the viking gene that codes for a Collagen type IV protein and localizes to membranes, green emission of the green fluorescent protein, GFP). Structures 3a and 3b are first and second generation dendrimers, respectively. Structure 4 is a polycationic red dye (PI)...

There are also examples of nanoreactors which have increased enzyme activity when encapsulated compared with bulk conditions. PICsomes that are stable to salt and elevated temperatures have been successfully developed using PEG-h-P( Asp) and are able to encapsulate trypsin without altering the original enzymatic activity [25]. Furthermore, these specifically designed PICsomes maintained their vesicular architecture at salt concentrations of 300 mM NaCl and temperatures up to 70°C, with only a subtle inaease in their size. For example, encapsulated nucleoside hydrolase has a substrate turnover number (kat) up to six times higher than the free enzyme [59]. Other enzymes, such as GOx and HRP, showed an 85% inaease in activity afta encapsulation in polyelectrolyte capsules [112], In addition, laccase entrapped in linear-dendritic based nanoreactors showed superior activity compared with its activity in bulk, and also inaeased temperature stability (up to 70 C) [19]. Howeva, the intrinsic branched architecture of den-drimers offers insufficient fluidity and space for entrapping larger biomolecules. 

Zhang etalP showed that the surface covered with dendritic gold clusters, which was formed by electrochemical deposition onto indium tin oxide (ITO) electrode modified with a polyelectrolyte multilayer, showed superhydrophobic properties after further deposition of an -dodecanethiol monolayer. The chemical bath deposition (CBD) has also been used to make nanostrucmred surfaces, thus, Hosono etaL fabricated a nanopin film of brucite-type cobalt hydroxide (BCH) and achieved a contact angle of 178° after further modification of lauric acid (LA). Shi et al7 described the use of galvanic cell reaction as a facile method to chemically deposit Ag nanostructures... 

Fig. 12 Alternative models to explain the non-linear growth mechanism of polyelectrolyte multilayer. The substrate is the horizontal slab. The film resulting from successive polymer adsorption steps is shown in different level of gray, a Island model, b Dendritic model. Reprinted with permission from Ref. [162]. Copyright (2011) American Chemical Society...

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