Methacrylated dextran

Chen FM, Zhao YM, Sun HH, Jin T, Wang QT, Zhou W, Wu ZF, Jin Y (2007) Novel gly-cidyl methacrylated dextran (dex-gma)/gelatin hydrogel scaffolds containing microspheres loaded with bone morphogenetic proteins formulation and characteristics. J Control Release 118(1) 65—77... 

Van Dijk-Wolthuis WNE, Van Steenbergen MJ, Underberg WJM, Hennink WE. Degradation kinetics of methacrylated dextrans in aqueous solution. J Pharm Sci 1997 86 413-417. 

Van Dijk-Wolthuis WNE, Tsang SKY, Kettenes-van den Bosch JJ, Hennink WE. A new class of polymerizable dextrans with hydrolyzable groups hydroxyethyl methacrylated dextran with and without oligolactate spacer. Polymer 1997 38 6235-6242. 

Dextran-based hydrogels were produced by the polymerisation of aqueous solutions of methacrylated dextran or lactate-hydroxyethyl methacrylate-derivatised dextran and implanted subcutaneously in rats for up to 6 weeks. The effects of initial water content and degree of substitution of these hydrogels on tissue response were examined and the relationship between in vitro and in vivo degradation behaviour was investigated. The results obtained indicated that these hydrogels were biocompatible and could be potential candidates for drug delivery systems. 20 refs. 

Microparticles of acidic and basic gelatin were used as carriers for the individual delivery of two different growth factors and were embedded in a hydrogel matrix, composed of glycidyl methacrylated dextran (Dex-GMA)/gelatin. This hybrid system allowed the independent release of BMP-2 or IGF-1 that facilitated cell attachment, proliferation, metabolism, and osteoblastic differentiation of cells in a synergistic manner [127]. 

Chen FM, Ma ZW, Dong GY, Wu ZF. Composite glycidyl methacrylated dextran (Dex-GMA)/gela-tin nanoparticles for localized protein delivery. Acta Pharmacol Sin 2009 30 485-93. 

In our procedure, methacrylated dextran (dex-MA) is obtained by reacting glycidyl methacrylate (GMA) with dextran in a suitable aprotic solvent (dimethylsulfoxide, (DMSO)), and 4-(, JV-dimethylamino)pyridine (DMAP) as acatalyst (Fig.2). 

Cationic hydrophilic Glycol chitosan, DEAE-dextran, poly(ethyleneimine), poly(trimethylaminoethyl methacrylate) iodide salt 0.5 M acetic acid with 0.3 M NaiSO, or 0.8 M NaNO.,... 

Figure 17 Permeability of uranine ( ), dextran 4.4K (O), and dextran 150K (A) through cross-linked poly(/V-isopropyl acrylamide-co-butyl methacrylate, 95 5 mol%) membrane. Error bars represent standard deviation in the slope of the curve of the receiver concentration of solute as a function of time at steady state. (From Ref. 37.)...

Jiang and Zhu (2000) and Qiu and Zhu (2001) have reported the fabrication of multilayered devices composed of stacks of compression-molded disks of alternating compositions. One type of disk is either P(SA-EG) or P[SA-co-TMAgly)-Z>-EG] and the other is a pH-sensitive, protein-loaded blend of, for example, poly(methacrylic acid) and polyethoxazoline. The release of model proteins, myoglobin, bovine serum albumin, and FITC-dextran, and compounds such as brilliant blue have been studied and pulsatile release profiles have been demonstrated (Jiang and Zhu, 2000 Qiu and Zhu, 2001). 

Avseenko et al. (2001) immobilized antigens onto aluminum-coated Mylar films by electrospray (ES) deposition. Various surface modifications of the metallized films were studied to determine their abilities to enhance sensitivity. The plastic surfaces were firsf cleaned by plasma discharge treatment, followed by coating with proteins (BSA and casein) or polymers such as poly (methyl methacrylate) or oxidized dextran, or they were exposed to dichlorodimethyl silane to create hydrophobic surfaces. Protein antigen was prepared in 10-fold excess sucrose and sprayed onto the surfaces to form arrays with spot diameters between 7 and 15 pm containing 1 to 4 pg protein. 

Significant research has been directed toward the use of polyelectrolyte complexes as blood compatible materials. Several investigators found that water-insoluble polyelectrolyte complexes can suppress blood coagulation [487-490]. Davison and coworkers reviewed and studied the biological properties of water-soluble polyelectrolyte complexes [491] between quatemized poly(vinyl imidazole) or polyvinyl pyridine) and excess sulfonated dextran or poly(methacrylic acid). By forming complexes with a stoichiometric excess of anionic charge, a more compact conformation with anionic character was obtained. 

Commonly employed water-insoluble supports for the covalent attachment of enzymes include synthetic supports such as acrylamide-based polymers, maleic anhydride-based polymers, methacrylic acid-based polymers, styrene-based polymers, and polypeptides, and natural supports such as agarose (Sepharose), cellulose, dextran (Sephadex), glass, and starch (Zaborsky, 1973). 

DDMC 2-Diethyl-aminoethyl-dextran-methyl methacrylate graft copolymer... 

Onishi Y, Eshita Y, Murashita A et al (2005) Synthesis and characterization of 2-diethyl-aminoethyl-dextran-methyl methacrylate graft copolymer for nonviral gene delivery vector. J Appl Polym Sci 98 9-14... 

Hydroxyethyl methacrylate Human immunodeficiency virus 1,1,1,3,3,3,-Hexamethyldisilazane Hydrophobically modified polycationic dextran Heteronuclear multiple quantum correlation High performance liquid chromatography Herpes simplex virus... 

Fig. 20 Synthesis of dextran methacrylate usable for the formation of hydrogels after photo-initiated cross-linking [175]...

Fig. 21 Three-dimensional porous structure of a dextran methacrylate hydrogel observed by means of SEM...

Transparent hydrogels useful for adhesion inhibitors, tissue adhesives, wound dressings, hemostatics and embolisation materials are obtained from dextran methacrylates via polymerisation with N-isopropylacrylamide in DMSO in the presence of azobisisobutyronitrile [176]. A broad variety of new hydrogels with different sensitivities and tunable degradation behaviour is accessible by grafting L-lactide onto 2-hydroxyethyl methacrylate (HEMA) and binding this polymerisable group on dextran via activation with N,N -carbonyldiimidazole (CDI, Sect. 4.2.2) [177]. 

Interestingly, CDI can also be utilised for the introduction of substituents by inter- or intramolecular coupling of OH moieties of the polysaccharide via a carbonate function. This synthesis was used to obtain dextran with 2-hydroxyethyl methacrylate moieties (dex-HEMA) and dex-HEMA with lactate spacer functions (Fig. 32). A new class of dextran derivatives (DS < 0.2) that can be polymerised containing hydrolysable groups is accessible [177]. 

Fig. 32 Conversion of dextran with hydroxyethyl methacrylate lactate using CDI yielding a carbonate-bound ester moiety...

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