Dextran conjugate

Gelatin core with dextran conjugate of drug 15 Lung, after intravenous injection Mitomycin-dextran conjugate... 

Add 10 mg of the protein to be coupled to the dextran solution. Other ratios of dextran-to-protein may be used as appropriate. For instance, if more than one protein or a protein plus a smaller molecule are both to be conjugated to the dextran backbone, the amount of protein added initially may have to be scaled back to allow the second molecule to be coupled latter. Many times, a small molecule such as a drug will be coupled to the dextran polymer first, and then a targeting protein such as an antibody conjugated secondarily. The optimal ratio of components forming the dextran conjugate should be determined experimentally to obtain the best combination possible. 

Purify the protein-dextran conjugate from unconjugated protein and dextran by gel filtration using a column of Sephacryl S-200 or S-300. Small molecules may be removed from a dextran conjugate by dialysis. 

Holmberg, A., and Meurling, F. (1993) Preparation of sulfhydrylhorane-dextran conjugates for boron neutron capture therapy. Bioconjugate Chem. 4, 570-573. 

Nakamura, S., Kato, A., and Kobayashi, K. (1990) Novel bifunctional lysozyme—dextran conjugate that acts on both Gram-negative and Gram-positive bacteria. Agric. Biol. Chem. 54, 3057-3059. 

Noguchi, A., Takahashi, T., Yamaguchi, T., Kitamura, K., Takakura, Y., Hashida, M., and Sezaki, H. (1992) Preparation and properties of the immunoconjugate composed of anti-human colon cancer monoclonal antibody and mitomycin C—Dextran conjugate. Bioconjugate Chem. 3, 132-137. 

Trypan blue (0.4%), a substance that is usually applied to identify dead cells, can be used as a quencher for some of the external dextran conjugates [fluorescein isothiocyanate (FITC)-dextran] (72,129). 

Macleod, A.D., Tolentino, L., and Tozer, T.N., Glucocorticoid-dextran conjugates as potential prodrugs for colon-specific delivery steady-state pharmacokinetics in the rat, Biopharm. DrugDisp., 15 151-161 (1994). 

Wileman, T. (1991). Properties of asparaginase-dextran conjugates. Adv. Drug Delivery Rev. 6(2), 167-180. 

Akhtar, M., Dickinson, E. (2003). Emulsifying properties of whey protein-dextran conjugates at low pH and different salt concentrations. Colloids and Surfaces B Biointerfaces, 31, 125-132. 

Choi, S.J., Kim, H.J., Park, K.H., Moon, T.W. (2005). Molecular characteristics of oval-bumin-dextran conjugates formed through the Mai Hard reaction. Food Chemistry, 92, 93-99. 

Fechner, A., Knoth, A., Scherze, I., Muschiolik, G. (2007). Stability and release properties of double-emulsions stabilised by caseinate-dextran conjugates. Food Hydrocolloids, 21, 943-952. 

Nomura, T., Saikawa, A., Morita, S., Sakaeda (ne Kakutani), T., Yamashita, F., Honda, K., Takakura, Y. and Hashida, M. (1998b) Pharmacokinetic characteristics and therapeutic effects of mitomycin C-dextran conjugates after intratumoural injection. J. Control Release, 52, 239-252. 

An alternative method for the synthesis of different dextran conjugates with fluorescent dyes is the reaction of a water-soluble amino dextran with the succinimidyl ester of the corresponding dye [360]. The amide linkage is more stable than the corresponding thiocarbamate formed with isothiocyanates. This method is displayed schematically in Fig. 54 for the preparation of 5- (and 6-) carboxynaphthofluorescein-labelled dextran from amino dextran (Fig. 47, [361,362]). 

An important consideration to the pharmacologist is the useful lifetime of a drug in the body. Protein hormones have been modified chemically to lower their rate of removal from the bloodstream, prolong the effect of the injected hormone, and thus reduce the required frequency of administration. The modification of animal insulin by coupling to protamine-zinc is probably the best-known example. Others are the studies by Marshall on the possibility of lengthening the lifetime in the bloodstream of injected proteins by supplying them as dextran conjugates... 

Dextran conjugated to fluorescein-5-isothiocyanate (dextran-FITC, m.w. 20-2000 kDa, 0.009 mol FITC per mole glucose) is used at a final concentration of 0.2 iM. Bovine serum albumin conjugated to fluorescein-5-isothiocyanate (BSA-FITC) containing 12 mol FITC per mole albumin (m.w. 66 kDa) is applied at 1-10 iMconcentration. Dye-conjugated probes are dialyzed before use against the exposure medium. Propidium iodide (PI) is used at a final concentration... 

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