One of the major limitations impeding the sensitivity and specificity of biomarker targeted nanoparticles is non-specific binding by biomolecules and uptake by the reticuloendothelial system (RES). We report the development of an antibiofouling polysiloxane containing amphiphilic diblock copolymer, poly(ethylene oxide)-block-poly(γ-methacryloxypropyltrimethoxysilane) (PEO-b-PγMPS), for coating and functionalizing high quality hydrophobic nanocrystals such as iron oxide nanoparticles and quantum dots. These PEOb-PγMPS coated nanocrystals were colloidally stable in biological medium and showed low nonspecific binding by macromolecules after incubation with 100% fetal bovine serum. Both in vitro experiments with macrophages and in vivo biodistribution studies in mice revealed that PEO-b-PγMPS copolymer coated nanocrystals have an antibiofouling effect that reduces non-specific cell and RES uptake. Surface functionalization with amine groups was accomplished through cocrosslinking the polysiloxane coating layer and (3-Aminopropyl) trimethoxysilane in aqueous solution. Tumor integrin α v β 3 targeting peptide cyclo-RGD ligands were conjugated on the nanoparticles through a heterobifunctional linker. The resulting integrin α v β 3 targeting nanoparticle conjugates showed improved cancer cell targeting with a stronger affinity to U87MG glioma cells, which have a high expression of α v β 3 integrins, but minimal binding to MCF-7 (low expression of α v β 3 integrins).

No abstract

We report the rational design and implementation of a new class of gel guest-assisted, ionic covalent organic framework (COF) membranes that exhibit superior H+ conduction. The as-synthesized COFs are postmodified via a lithiation (or sodiation) treatment. The hydrophilic Li or Na ions in the COFs form a dense and extensive hydrogen-bonding network of H2O molecules with mobile H+ at the periphery, thereby transforming COFs into H+ conductors. Then, the ionic COFs are assembled into a flexible H+ conductor membrane via a gelation process, where the organic gel provides both mechanical strength and additional H+ carriers for fast H+ conduction. The final COF-based membrane exhibits an excellent H+ conductivity of 1.3 × 10–1 S cm–1 at 313 K and 98% relative humidity, which are the highest values of the COF-based H+ conductors reported until now and are even comparable with those of the typical commercial Nafion membrane. We anticipate that the two-in-one strategy would open up a porous COF-driven new molecular framework and membrane architectural design/opportunity for development of next-generation ionic conductors.

No abstract

No abstract

No abstract

No abstract

A series of efficient adsorbents were prepared by impregnating mesoporous silica SBA-15 with different amounts of mono­ethanol­amine (MEA) and diethanol­amine (DEA) in order to improve CO2 capture capacity. The textural properties of pure and modified mesoporous SBA-15 materials were characterized by X-ray diffraction characterization, transmission electron microscopy, N2 adsorption–desorption test, and thermogravimetric analysis. When the ratio of DEA to SBA-15 is below 2, these molecules loaded on the support are relatively far away from saturating and allow the accessibility of CO2 molecules to the inner adsorption sites. Further increasing of the amine loading would reduce opportunities of CO2 to contact with internal amino sites, because the amine was covered in a multilayer form or even caking form on the SBA-15 pore surface. The similar performance was observed for MEA. Therefore, the adsorption capacity of CO2 increases with the amount of DEA or MEA content, but when the amount of MEA or DEA loaded on the mesoporous SBA-15 is further increased, the CO2 capture is influenced by the packing effect on the mesoporous hexagonal silica. Temperature effect on adsorption was also studied in the range of 30–90 °C, showing that, with the increase of temperature, the adsorptive amounts of adsorbents lessened gradually from the highest values at 30 °C since the thermodynamically controlled process. The mesoporous SBA-15 material impregnated with MEA or DEA can provide a perspective to further explore effective adsorbents for CO2 capture.