Hydrophobized polysaccharide

Akiyoshi K, Deguchi S, Moriguchi N et al (1993) Self-aggregates of hydrophobized polysaccharides in water. Formation and characteristics of nanoparticles. Macromolecules 26 3062-3068... 

Y. Kakizawa, K. Akiyoshi, K. Nakamura, and J. Sunamoto, in Enzymatic Activity of Lipase Complexed with Nanoparticle of Hydrophobized Polysaccharide, Kyoto, Japan, 1998, p. III-806. Society of Polymer Science, Japan (Spsj). 

Because the micellar interior is far from being rigid, a solubilized substrate is relatively mobile. Like micelle formation, solubilization is a dynamic equilibrium process. Representative recent examples are the solubilization of benzene, naphthalene, anthracene, and pyrene in aqueous solution by the addition of 1-dodecanesulfonic acid [391], the solubilization of fullerene Ceo in aqueous solutions of the non-ionic surfactant Triton X-100 [392], and the solubilization of a cholesteryl-group bearing pullulane (a hydrophobized polysaccharide) [393]. 

Fig. 1. Preparation of 0-palmitoyl mannan-anchored vesicles. Liposomes were prepared by hand-shaking method and coating of liposomes with these hydrophobized polysaccharides (OPM) was performed by incubation of aqueous soiutions of polysaccharide derivatives with preformed liposomal dispersion...

Akiyoshi, K. Deguchi, S. Tajima, H. Nishikawa, T. Sunamoto, J. Microscopic structure and thermoresponsiveness of a hydrogel nanoparticle by self-assembly of a hydrophobized polysaccharide. Macromolecules 1997, 30, 857-861. 

Fukui H, Akiyoshi K, Sunamoto J. OAV emulsion of a-linolenic acid stabilized with hydrophobized polysaccharide. Its effect on the growth of human colon cancer cells. J Biomater Sci Polym Edn 1996 7 829-838. 

Fukui H, Akiyoshi K, Sato S, Sunamoto J, Yamaguchi S, Numata M. Anticancer activity of polyunsaturated fatty acid emulsion stabilized by hydrophobized polysaccharide. J Bioactive Compatible Polym 1993 8 305-316. 

Nishikawa T., Akiyoshi K., Sunamoto J. Supramolecular assembly between nanoparticles of hydrophobized polysaccharide and soluble protein complex-... 

Polysaccharides with Surfactant Micelles. Consider a solution of a fairly hydrophobic polysaccharide, such as a cellulose ether. The hydrophobic groups cause a weak attractive interaction, leading to a somewhat increased viscosity at low shear rates. If an anionic small-molecule surfactant is added, say SDS (sodium dodecyl sulfate), at a concentration above the CMC (critical micellization concentration), micelles are formed that interact with the polymer more specifically, one or a few polymer chains can pass through a micelle. In this way, polymer chains can be cross-linked. If now the polymer concentration c is below c (the chain overlap concentration), mainly intramolecular junctions are formed. If c > c, however, a gel results. In this manner, viscoelastic gels can be made with a modulus of the order of 10 Pa. 

A solution of a moderately hydrophobic polysaccharide can often be made to gel by adding a small-molecule surfactant at a concentration above the CMC. The surfactant then makes micelles through many of which one or more polysaccharide chains pass, thereby forming cross-links. A fairly weak gel results. 

Cellulose fibers that are partially hydrophobized by alkyl chains as well as cellulose itself align on water surfaces to form two-dimensional crystals, which are quite regular, in the direction of the polymer chain. In case of alkylated cellulose ( hairy rods ) multilayer grids of molecular size can be synkinesized if the direction of the LB plate is changed by 90° in each application (Fig. 4.6.4). Similar hydrophobized polysaccharides have also been used as hydrogel nanoparticles to bind albumin protein in water (Nishikawa et al., 1996)... 

Akiyoshi K, et al. Supramolecular assembly of hydrophobized polysaccharides. Supramol Sci. 1996 3 157-63. 

Nishikawa, T., Akiyoshi, K., and Sunamoto, J. Macromolecular conq)lexation between serum albumin and die self-assembled hydrogel nanoparticle of hydrophobized polysaccharides. J. American Chem. Soc. 118 (26), 1996,6110-6115. 

Among the associative polymers, the hydrophobized polysaccharides, e.g. CDs, dextran... 

Aggregates formed from hydrophobized polysaccharides which can solubilize poorly soluble drugs entrapped into their hydrophobic microdomains are known [20]. It should be pointed out that biochemical stability of these drugs is considerably increased when they are entrapped in hydrophobic domains of the above hydrophobized polysaccharides. 

A NOVEL HYDROPHOBIZED POLYSACCHARIDE/ONCOPROTEIN COMPLEX VACCINE FORHER2 GENE EXPRESSING CANCER... 

In our present study, the HER2 protein required hydrophobized polysaccharides for the induction of a CTL response and the rejection of HER2 expressing tumor cells in vivo. These CTLs were K restricted CD8 T lymphocytes specifically recognizing the HER2 derived peptide p63-71, a part of the HER2 protein used for the vaccine, indicating that a soluble oncoprotein could enter the class 1 pathway by the help of CHM or CHP. 

First, the partition of hydrophobized polysaccharide (HP)-coated liposomes was investigated in aqueous two-phase systems such as polyfethylene oxide) (PEO) (top phase)/pullulan (bottom phase) and poly(ethylene oxide) (top)/ dextran (bottom phase). HPs such as cholesterol-bearing pullulan, dextran, and mannan nicely coated the liposomal surface. When conventional uncoated liposomes were added to the aqueous two-phase system, they mostly located at the interface between the two polymer phases. The HP-coated liposomes, on the other hand, were significantly partitioned into the bottom polysaccharide phase, depending on the structure of the HP on the liposomal surface. 

TABLE 1 Partition Efficiency (%) of Hydrophobized Polysaccharide-Coated Liposomes into an Aqueous 6.0% (w/w) PEO-20/8.0% (w/w) Pullulan-50 System... 

AH experiments were performed in triplicate. The values in parentheses are standard deviations. R indicates the weight ratio of hydrophobized polysaccharides to lipids (mg/mg). 

Weight ratio of hydrophobized polysaccharides to totai liposomal lipids... 

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