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Cross-Linking with Carbodiimides

One of the most common reactions of the HA carboxylic group with amino acids and diamines is condensation in presence of HOBT in water/DMSO [18]. It is known that one of the best condensation methods of carboxylic and amino functions is the reaction in the presence of DCC (dicyclohexylcarbodiamide). One of the first studies of the condensation with DCC was conducted in 1991 [19]. A similar method was used for reaction with different amines [20]. Unfortunately, DCC required the reaction in non-aqueous conditions. However, there is a possibility to perform cross-linking with EDC - water soluble analogue of DCC [21]. A similar process, which mentioned condensation with EDC and resulted in cross-linked hydrogels is described in [22,23]. [Pg.124]

General methods for cross-linking of biopolymers such as hydroxyethylcellulose (HEC), carboxymethylcellulose sodium salt (CMC Na) and hyalnronic acid (HA) using water soluble carbodiamide are summarized in a review published in 2005 [24]. The interesting invention described the synthesis of water-insoluble derivative of hyaluronic acid cross-linked with biscarbodiimide [25]. [Pg.124]

An interesting method of connecting two hyaluronic acid fragments through carboxylic and primary amine functions using the Ugi approach is described in the patent [27]. In the method the primary amine was generated by deacylation, then two molecules were allowed to react in the presence of formaldehyde and cyclohexylisocyanide (Eigure 5.2). The Ugi reaction allowed scientists to make cross-hnked HA with an N-substituted amide bond, in which carboxylic and amino functions came from the different HA molecules. [Pg.125]

Another possible way to synthesize cross-hnked HA is by using bi-functional reagents. The cross-hnked HA product is synthesized after reaction of HA with dihydrazide in the presence of HOBT and carbodiimide (Eigure 5.3) [28]. In this reachon only the carboxylic functions from both HA molecules were used for cross-hnking. [Pg.125]

Another example of the synthesis of cross-hnked HA with a dihydrazide bridge is described in [29]. For a formation of the bond between hyaluronan and primary amine, carbodiimide and N-hydroxysulfosuccinimide were used. The authors synthesized many [Pg.125]


PLLA, Plasma glow discharged PLLA cross-linked with carbodiimide, glutara-Idehyde-cross-linked PLLA (pH 7.4) ... [Pg.348]

Figure 5.1 Hyaluronic acid cross-linking with carbodiimide... Figure 5.1 Hyaluronic acid cross-linking with carbodiimide...
Here we report an attempt to immobilize an urokinase antithrombin III PGEirmethyl dopa conjugate on albumin blended chitosan membranes and the evaluation of their antithrombotic and permeability properties. Further studies have also been undertaken to improve the mechanical properties of the albumin blended chitosan membranes through optimum cross-linking with carbodiimide. A novel approach of producing other protein blends of chitosan, as non-thrombogenic membranes, for improved permeability had been demonstrated and compared to that of the standard cellulose membranes. [Pg.298]

CaM was purified from porcine brain. The purity of proteins was examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and isoelectric focusing. CaM and PDE were cross-linked with l-ethyl-3(3-dimethylamino-propyl) carbodiimide (EDC) or N-succinimidyl 3-(2-pyridyldithio)propionate (SPDP) in a buffer solution of 0.1 M HEPES (pH 7.1) in the presence of 1 mM CaCl2. After a buffer solution containing 2 mM EGTA added into the reaction solution, the CaM-PDE hybrid was separated from other ingredients by gel chromatography on a Sepharose CL-6B solumn. [Pg.357]

Four products were obtained containing between 2 and 6 moles of amine per plastocyanin. More recently the reaction has been carried out to yield single and double modified products. No effect of modification at 42-45 on the rate of the PC u(I) reduction of P700 is reported, suggesting that these residues are not involved in the reaction. In a further elaboration the reaction of plastocyanin, cross-linked (by carbodiimide treatment) to cytochrome f at the remote site, with P700 has been studied and the effects of Mg " and Na" explored [158]. [Pg.219]

Polymers with intramolecular cross-links have organized spatial structures, and are good models for the tertiary structure of proteins (26,27,1 ). In the studies discussed here poly Glu52Lys33Tyr15 (No. 3) was internally cross-linked with Woodward s reagent K or ionic carbodiimide and fractionated on Sephadex G-100. The number of cross-links in each fraction was determined by amino acid analysis. In addition, the parent polymer was fractionated in the same way to provide standards for comparison with the cross-linked polypeptides. [Pg.215]

Antisera to cloxacillin/oxacillin/dicloxacillin and cefuroxime were also produced by similar procedures and successfully utilized in methods for the detection of these antibiotics in milk (34). Unfortunately, a number of other -lactams including aminopenicillins and some cephalosporins were not amenable to this mixed anhydride procedure. Thus, a carrier protein derivatization procedure was used to allow cross-linking of cephalosporins, such as cephataxime that has an acetoxy side chain, to ovalbumin. Because acetoxy groups react readily with the heterocyclic nitrogen atoms, the latter were introduced into ovalbumin through the carbodiimide-mediated derivatization of protein carboxyl groups with amino-methylpyridine (34). [Pg.837]


See other pages where Cross-Linking with Carbodiimides is mentioned: [Pg.72]    [Pg.1429]    [Pg.371]    [Pg.124]    [Pg.72]    [Pg.1429]    [Pg.371]    [Pg.124]    [Pg.252]    [Pg.10]    [Pg.1036]    [Pg.270]    [Pg.679]    [Pg.349]    [Pg.102]    [Pg.3539]    [Pg.3844]    [Pg.20]    [Pg.231]    [Pg.608]    [Pg.126]    [Pg.125]    [Pg.102]    [Pg.694]    [Pg.293]    [Pg.57]    [Pg.600]    [Pg.319]    [Pg.153]    [Pg.170]    [Pg.356]    [Pg.453]    [Pg.264]    [Pg.361]    [Pg.84]    [Pg.126]    [Pg.846]    [Pg.846]    [Pg.373]    [Pg.168]    [Pg.92]    [Pg.121]    [Pg.159]    [Pg.174]    [Pg.191]    [Pg.197]    [Pg.197]   


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