Surface bioconjugation

Kumar, P., Agarwal, S.K., and Gupta, K.C. (2004) N-(3-Trifluoroethanesulfonyloxypropyl)-anthraqui-none-2-carboxamide a new heterobifunctional reagent for immobilization of biomolecules on a variety of polymer surfaces. Bioconjugate Chem. 15, 7-11. 

Yan, M., Cai, S.X., Wybourne, M.N., and Keana, J.F.W. (1994) N-Hydroxysuccinimide ester functionalized perfluorophenyl azides as novel photoactivatable heterobifunctional cross-linking reagents. The covalent immobilization of biomolecules to polymer surfaces. Bioconjugate Chem. 5, 151-157. 

POC-click is formed by thermo-cross-linking the mixture of pre-POC-N (azide-containing POC prepolymer) and pre-POC-Al (alkyne-containing POC prepolymer) the process applies synchronous binary cross-link mechanism, esterification, and thermal click reaction, and the residual azide groups on the surface of POC-click film or scaffold paved the way of surface bioconjugation through strain-promoted alkyne-azide cycloaddition (SPAAC), another copper-free click reaction. 

Kneuer, C., Sameti, M., Bakowsky, U., Schiestel, T., Schirra, H., Schmidt, H., and Lehr, C.M., Surface modified silica-nanoparticles can enhance transfection in vitro a novel class of non-viral DNA vectors, Bioconjugate Chemistry, 2000, 11, 926-932. 

Nakaji-Hirabayashi T, Kato K, Iwata H (2009) Surface-anchoring of spontaneously dimerized epidermal growth factor for highly selective expansion of neural stem cells. Bioconjug Chem 20 102-110... 

Takemoto N, Teramura Y, Iwata H (2011) Islet surface modification with urokinase through DNA hybridization. Bioconjug Chem 22 673-678... 

Teramura Y, Iwata H (2008) Islets surface modification prevents blood-mediated inflammatory responses. Bioconjug Chem 19 1389-1395... 

Figure 7.8 The pendent groups available on the surface of dendrimer molecules are highly varied. Some groups provide functional or reactive groups for bioconjugation, while other groups create unique solubility characteristics for the dendrimer.

Figure 7.25 The multivalent nature of dendrimers can be used to add increased functionality to surfaces. Aminopropyl silane surfaces can be activated with either PDITC or through use of a cyclic anhydride plus DCC/ NHS to give amine-reactive surfaces. These reactive surfaces can be used to couple amine-dendrimers to provide a high density of amine groups on the surface for further bioconjugation.

Figure 9.58 QDs made using the TOPO process typically have a layer of these molecules associated with their outer surface. The TOPO groups must be displaced and replaced by water-soluble groups to provide biocompatibility for bioconjugation purposes.

The reactions used for coupling affinity ligands to nanoparticles or microparticles basically are the same as those used for bioconjugation of molecules or for immobilization of ligands onto surfaces or chromatography supports. However, with particles, size can be a major factor in how a reaction is performed and in its resultant reaction kinetics. Since particle types can vary from the low nanometer diameter to the micron size, there are dramatic differences in how such particles behave in solution and how the density of reactive groups or functional groups affects reactions. 

The following sections discuss many of the major particle types and provide bioconjugation options for the coupling of ligands to the surface of functionalized particles. Some additional nanoparticle constructs, including gold particles, dendrimers, carbon nanotubes, Buckyballs and fullerenes, and quantum dots are discussed more fully elsewhere (see Chapter 7 Chapter 9, Section 10 Chapter 15 and Chapter 24). 

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