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Macroporous Materials (macroporou + material)
Selected AbstractsRapid production of a plasmid DNA encoding a malaria vaccine candidate via amino-functionalized poly(GMA- co -EDMA) monolithAICHE JOURNAL, Issue 11 2008Michael K. Danquah Abstract Malaria is a global health problem; an effective vaccine is urgently needed. Due to the relative poverty and lack of infrastructure in malaria endemic areas, DNA-based vaccines that are stable at ambient temperatures and easy to formulate have great potential. While attention has been focused mainly on antigen selection, vector design and efficacy assessment, the development of a rapid and commercially viable process to manufacture DNA is generally overlooked. We report here a continuous purification technique employing an optimized stationary adsorbent to allow high-vaccine recovery, low-processing time, and, hence, high-productivity. A 40.0 mL monolithic stationary phase was synthesized and functionalized with amino groups from 2-Chloro-N,N-diethylethylamine hydrochloride for anion-exchange isolation of a plasmid DNA (pDNA) that encodes a malaria vaccine candidate, VR1020-PyMSP4/5. Physical characterization of the monolithic polymer showed a macroporous material with a modal pore diameter of 750 nm. The final vaccine product isolated after 3 min elution was homogeneous supercoiled plasmid with gDNA, RNA and protein levels in keeping with clinical regulatory standards. Toxicological studies of the pVR1020-PyMSP4/5 showed a minimum endotoxin level of 0.28 EU/mg pDNA. This cost-effective technique is cGMP compatible and highly scalable for the production of DNA-based vaccines in commercial quantities, when such vaccines prove to be effective against malaria. © 2008 American Institute of Chemical Engineers AIChE J, 2008 [source] Processing Routes to Macroporous Ceramics: A ReviewJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 6 2006André R. Studart Macroporous ceramics with pore sizes from 400 nm to 4 mm and porosity within the range 20%,97% have been produced for a number of well-established and emerging applications, such as molten metal filtration, catalysis, refractory insulation, and hot gas filtration. These applications take advantage of the unique properties achieved through the incorporation of macropores into solid ceramics. In this article, we review the main processing routes that can be used for the fabrication of macroporous ceramics with tailored microstructure and chemical composition. Emphasis is given to versatile and simple approaches that allow one to control the microstructural features that ultimately determine the properties of the macroporous material. Replica, sacrificial template, and direct foaming techniques are described and compared in terms of microstructures and mechanical properties that can be achieved. Finally, directions to future investigations on the processing of macroporous ceramics are proposed. [source] Preparation and HPLC applications of rigid macroporous organic polymer monolithsJOURNAL OF SEPARATION SCIENCE, JSS, Issue 10-11 2004Frantisek Svec Abstract Rigid porous polymer monoliths are a new class of materials that emerged in the early 1990s. These monolithic materials are typically prepared using a simple molding process carried out within the confines of a closed mold. For example, polymerization of a mixture comprising monomers, free-radical initiator, and porogenic solvent affords macroporous materials with large through-pores that enable applications in a rapid flow-through mode. The versatility of the preparation technique is demonstrated by its use with hydrophobic, hydrophilic, ionizable, and zwitterionic monomers. Several system variables can be used to control the porous properties of the monolith over a broad range and to mediate the hydrodynamic properties of the monolithic devices. A variety of methods such as direct copolymerization of functional monomers, chemical modification of reactive groups, and grafting of pore surface with selected polymer chains is available for the control of surface chemistry. Since all the mobile phase must flow through the monolith, the convection considerably accelerates mass transport within the molded material, and the monolithic devices perform well, even at very high flow rates. The applications of polymeric monolithic materials are demonstrated mostly on the separations in the HPLC mode, although CEC, gas chromatography, enzyme immobilization, molecular recognition, advanced detection systems, and microfluidic devices are also mentioned. [source] Studying porous materials with krypton-83 NMR spectroscopyMAGNETIC RESONANCE IN CHEMISTRY, Issue S1 2007Zackary I. Cleveland Abstract This report is the first review of 83Kr nuclear magnetic resonance as a new and promising technique for exploring the surfaces of solid materials. In contrast to the spin I = 1/2 nucleus of 129Xe, 83Kr has a nuclear spin of I = 9/2 and therefore possesses a nuclear electric quadrupole moment. Interactions of the quadrupole moment with the electronic environment are modulated by surface adsorption processes and therefore affect the 83Kr relaxation rate and spectral lineshape. These effects are much more sensitive probes for surfaces than the 129Xe chemical shielding and provide unique insights into macroporous materials in which the 129Xe chemical shift is typically of little diagnostic value. The first part of this report reviews the effect of quadrupolar interactions on the 83Kr linewidth in zeolites and also the 83Kr chemical shift behavior that is distinct from that of its 129Xe cousin in some of these materials. The second part reviews hyperpolarized (hp) 83Kr NMR spectroscopy of macroporous materials in which the longitudinal relaxation is typically too slow to allow sufficient averaging of thermally polarized 83Kr NMR signals. The quadrupolar-driven T1 relaxation times of hp 83Kr in these materials are sensitive to surface chemistry, surface-to-volume ratios, coadsorption of other species on surfaces, and surface temperature. Thus, 83Kr T1 relaxation can provide information about surfaces and chemical processes in macroscopic pores and can generate surface-sensitive contrast in hp 83Kr MRI. Copyright © 2007 John Wiley & Sons, Ltd. [source] Using Nano-Cast Model Porous Media and Integrated Gas Sorption to Improve Fundamental Understanding and Data Interpretation in Mercury PorosimetryPARTICLE & PARTICLE SYSTEMS CHARACTERIZATION, Issue 1 2006Sean P. Rigby Abstract The mechanisms of entrapment, and the nanoscopic spatial distribution, of the residual mercury within nano-cast and amorphous porous media (pore sizes ~1,100 nm) following high-pressure penetration have been studied. It has been shown that, even at the nano-scale, one of the same two principle mechanisms that have been observed previously in mercury porosimetry experiments on macroscopic glass pore models also occur within a given amorphous, nanoporous solid. Using percolation theory to interpret novel, integrated gas sorption experiments, entrapment was shown to arise, either because of the presence of sufficiently narrow pore necks interspersed between larger voids, or due to non-random, longer-range structural heterogeneity. The threshold "snap-off" ratio parameter for the entrapment process has also been directly measured but found to be considerably smaller than seen previously for macroporous materials. The techniques employed here enable information not previously available for nanoporous systems to be determined, and therefore to be incorporated into simulations of mercury porosimetry on those materials. [source] TiO2 -Modified Macroporous Silica Foams for Advanced Enrichment of Multi-Phosphorylated PeptidesCHEMISTRY - A EUROPEAN JOURNAL, Issue 11 2009Jingjing Wan Abstract Enriching peptides: Novel TiO2 -modified macroporous materials (Ti-MOSF, see figure) have been synthesized with high surface area, large pore volume, and functional surfaces that are rich in coordinatively unsaturated TiIV species, which can be applied in the specific extraction of phosphopeptides and which show a preferential capture of multi-phosphorylated peptides with low detection limits and high selectivity. [source] | |||||||||||||