Physicochemical properties poly

In the course of studies on the physicochemical properties of natural polymers in aqueous solution, attention has been drawn to pectic acid, i.e. poly (a-D)galacturonic acid as a potential model of a rigid polysaccharide. 

Although there is evidence that all poly(HA) depolymerases cleave the polyesters by the same mechanism (catalytic triad), the poly(3HO) depolymerase differs considerably from poly(HASCL) depolymerases in terms of primary sequence and polymer-binding. This might be due to different approaches of these enzymes to get access to the polymers reflecting the distinctive physicochemical properties of poly(HASCL) and poly(HMCLA) rather than coevolution. 

Kirsh YE (1998) Water soluble poly-N-vinylamides synthesis and physicochemical properties. Wiley, Chichester... 

Formation of a complex between DNA and polycationic compounds appears to be the initial and quite possibly a critical parameter for nonviral gene delivery. Several synthetic vector systems, which are generally cationic in nature, including poly(lysines), cationic liposomes or various types of block copolymers and recently dendrimers, have been shown to self-assemble with plasmid DNA [13-15] [16]. Specific physicochemical properties manifested by these DNA complexes depend on the type of cationic agent used however, interesting patterns for such interactions are beginning to evolve [17, 18]. Under certain conditions, the interaction of DNA with polyvalent cations results in... 

Hydrocarbon polymers (HCP) are used not only as fuel components but also as binders of crystalline oxidizers and metal powders in the formulation of pyrolants, similar to composite propellants and plastic-bonded explosives. There are many types of HCP, the physicochemical properties of which are dependent on their molecular structures. The viscosity, molecular mass, and functionality of the poly-... 

Poly(N-isopropylacrylamide) (polyNIPAAM), formed by a free radical polymerization of N-isopropylacrylamide, is a water soluble, temperature sensitive polymer. In aqueous solution, it exhibits a lower critical solution temperature (LCST) in the range of 30-35 C depending on the concentration and the chain length of the polymer. Thus, as the solution temperature is raised above the LCST, the polymer undergoes a reversible phase transition characterized by the separation of a solid phase which redissolves when the solution temperature is lowered below the LCST. Its physicochemical properties have been investigated by several laboratories (1-3). 

Physicochemical properties of polyplexes greatly depend on the ratio of poly cation and DNA units in the mixture Z=[polycation units]/[DNA bases] referred to as composition of the mixture (Kabanov and Kabanov, 1995). In the case of polycations containing amino groups, the composition of the mixture is commonly expressed as N/P ratio, i.e., the ratio of the numbers of amino groups of the poly cation to phosphate groups of the DNA. It should be emphasized that the composition of the complex formed after mixing of the polycation and DNA solutions, [Pg.153]

Harada, A., Togawa, H. and Kataoka, K. (2001) Physicochemical properties and nuclease resistance of antisense-oligodeoxynucleotides entrapped in the core of polyion complex micelles composed of poly(ethylene glycol)-poly (L-Lysine) block copolymers. Eur. J. Pharm. Sci., 13, 35—42. 

Nishikawa, M., Takemura, S., Takakura, Y. and Hashida, M. (1998) Targeted delivery of plasmid DNA to hepatocytes in vivo optimization of the pharmacokinetics of plasmid DNA/galactosylated poly(L-lysine) complexes by controlling their physicochemical properties. J. Pharmacol. Exp. Then, 287, 408—415. 

Synthetic polymer. Among the cationic synthetic polymers used for gene delivery are polyethylenimine (PEI), polyamidoamine dendrimers, and poly(2-dimethylaminoethyl methacrylate).161-164 Depending on the flexibility (or rigidity) of the polymers, they form either a small (<100 nm) DNA polyplex or a large (>1 to 10 pm) DNA polyplex.165 More detailed physicochemical properties and their transfection efficacy are to be discussed. 

Specific carbohydrate ligands may be linked to these polymers in order to enhance the cell-adhesion properties of the biomaterial or in order to modify their physicochemical properties. An example is a biomimetic surfactant polymer of a poly(vinylamine) backbone bearing pendant maltoheptose units to increase local hydration and to inhibit non-specific adsorption.102... 

Pinel and co-workers, on the other hand, recently reviewed the use of (poly) saccharides in the telomerization reaction as well as the physicochemical properties of the obtained products [22]. 

Hamieh T, Schultz J. 2002. New approach to characterise physicochemical properties of solid substrates by inverse gas chromatography at infinite dilution II. Study of the transition temperatures of poly (methyl methacrylate) at various tacticities and of poly (methyl methacrylate) adsorbed on alumina and silica. J. Chromatogr. A 969 27-36. 

Being acquainted with the structure of poly(a-olefin)s, one may reasonably explain some of the differences in their physicochemical properties. For example, isotactic polypropylene, the chains of which in the helical conformation can be closely packed, has rather a high density (0.92-0.94 g/cm3) and melting point (175°C) and is insoluble in low-boiling aliphatic hydrocarbons at boiling point. Syndiotactic polypropylene, consisting of chains in the form of binary helices, which cannot be packed so closely as in the previous case, has a density of 0.89-0.91 g/cm3 and a melting point of 135°C, which is 40 k lower from that of isotactic polypropylene syndiotactic polypropylene is also moderately soluble in... 

Structure and Physicochemical Properties of Poly alky Isiloxane Monolayers 195... 

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