Anchoring of histidine-tagged proteins to molecular printboards: self-assembly, thermodynamic modeling, and patterning

In this paper the multivalent binding of hexahistidine (His6)-tagged proteins to beta-cyclodextrin (beta-CD) self-assembled monolayers (SAMs) by using the nickel(II) complex of a hetero-divalent orthogonal adamantyl nitrilotriacetate linker (4) is described. Nonspecific interactions were suppressed by using monovalent adamantyl-hexa(ethylene glycol) derivative 3. With the mono-His6-tagged maltose binding protein (His6-MBP), thermodynamic modeling based on surface plasmon resonance (SPR) titration data showed that the MBP molecules in solution were linked, on average, to Ni.4 in 1:1 stoichiometry. On the surface, however, the majority of His(6)-MBP was complexed to surface-immobilized beta-CDs through three Ni.4 complexes. This difference is explained by the high effective beta-CD concentration at the surface and is a new example of supramolecular interfacial expression. In a similar adsorption scheme, SPR proved that the alpha-proteasome could be attached to beta-CD SAMs in a specific manner. Patterning through microcontact printing of (His6)4-DsRed-fluorescent timer (DsRed-FT), which is a tetrameric, visible autofluorescent protein, was carried out in the presence of Ni.4 Fluorescence measurements showed that the (His6)4-DsRed-FT is bound strongly through Ni.4 to the molecular printboard.     

关于亚纯p叶函数的新子类

本文引进和研究亚纯ｐ叶函数类的新子类，建立了包含关系，讨论了类中函数的积分变换等性质。     

Synthetic Multivalent Glycopeptide‐Lipopeptide Antitumor Vaccines: Impact of the Cluster Effect on the Killing of Tumor Cells

Multivalent synthetic vaccines were obtained by solid‐phase synthesis of tumor‐associated MUC1 glycopeptide antigens and their coupling to a Pam₃Cys lipopeptide through click reactions. These vaccines elicited immune responses in mice without the use of any external adjuvant. The vaccine containing four copies of a MUC1 sialyl‐T_N antigen showed a significant cluster effect. It induced in mice prevailing IgG_2a antibodies, which bind to MCF‐7 breast tumor cells and initiate the killing of these tumor cells by activation of the complement‐dependent cytotoxicity complex.     

Localized Template‐Driven Functionalization of Nanoparticles by Dynamic Combinatorial Chemistry

We have developed a method for the localized functionalization of gold nanoparticles using imine‐based dynamic combinatorial chemistry. By using DNA templates, amines were grafted on the aldehyde‐functionalized nanoparticles only if and where the nanoparticles interacted with the template molecules. Functionalization of the nanoparticles was controlled solely by the DNA template; only amines capable of interacting with DNA were bound to the surface. Interestingly, even though our libraries contained only a handful of simple amines, the DNA sequence influenced their attachment to the surface. Our method opens up new opportunities for the synthesis of multivalent, nanoparticle‐based receptors for biomacromolecules.     

Multivalent Polymer Nanocomplex Targeting Endosomal Receptor of Immune Cells for Enhanced Antitumor and Systemic Memory Response

We have designed and synthesized linear polymer‐based nanoconjugates and nanocomplexes bearing multivalent immunostimulatory ligands and also demonstrated that the synthetic multivalent nanocomplexes led to an enhanced stimulation of immune cells in vitro and antitumor and systemic immune memory response in vivo. We have developed hyaluronic acid (HA)‐based multivalent nanoconjugates and nanocomplexes for enhanced immunostimulation through the combination of multivalent immune adjuvants with CpG ODNs (as a TLR9 ligand) and cationic poly(L ‐lysine) (PLL; for the enhancement of cellular uptake). The multivalent HA‐CpG nanoconjugate efficiently stimulated the antigen‐presenting cells and the multivalent PLL/HA‐CpG nanocomplex also led to an enhanced cellular uptake as well as continuous stimulation of endosomal TLR9. The mice vaccinated with dendritic cells treated with the multivalent nanocomplex exhibited tumor growth inhibition as well as a strong antitumor memory response.     

Multivalent Aptamer–RNA Conjugates for Simple and Efficient Delivery of Doxorubicin/siRNA into Multidrug‐Resistant Cells

Multivalent aptamer–siRNA conjugates containing multiple mucin‐1 aptamers and BCL2‐specific siRNA are synthesized, and doxorubicin, an anthracycline anticancer drug, is loaded into these conjugates through intercalation with nucleic acids. These doxorubicin‐incorporated multivalent aptamer–siRNA conjugates are transfected to mucin‐1 overexpressing MCF‐7 breast cancer cells and their multidrug‐resistant cell lines. Doxorubicin‐incorporated multivalent aptamer–siRNA conjugates exert promising anticancer effects, such as activation of caspase‐3/7 and decrease of cell viability, on multidrug‐resistant cancer cells because of their high intracellular uptake efficiency. Thus, this delivery system is an efficient tool for combination oncotherapy with chemotherapeutics and nucleic acid drugs to overcome multidrug resistance.

     

Metal–Organic Frameworks (MOFs) as Multivalent Materials: Size Control and Surface Functionalization by Monovalent Capping Ligands

Control over particle size and composition are pivotal to tune the properties of metal organic frameworks (MOFs), for example, for biomedical applications. Particle‐size control and functionalization of MIL‐88A were achieved by using stoichiometric replacement of a small fraction of the divalent fumarate by monovalent capping ligands. A fluorine‐capping ligand was used to quantify the surface coverage of capping ligand at the surface of MIL‐88A. Size control at the nanoscale was achieved by using a monovalent carboxylic acid‐functionalized poly(ethylene glycol) (PEG‐COOH) ligand at different concentrations. Finally, a biotin–carboxylic acid capping ligand was used to functionalize MIL‐88A to bind fluorescently labeled streptavidin as an example towards bioapplications.