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Gómez, J.M.; Deere, J.; Goradia, D.; Cooney, Jakki C.; Magner, Edmond; Hodnett, B.K.

doi:10.1023/a:1024057605239

Cited by 21 publications

(3 citation statements)

References 9 publications

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“…In contrast, Wright and co-workers claimed superiority of trypsin immobilized on SBA-15 as support compared to MCM-41 in the hydrolysis of N -α-benzoyl- dl -arginin-4-nitroaniline. , It was shown that the larger pore diameter of SBA-15 is advantageous in terms of substrate diffusion and pore blocking. Gomez et al studied the transesterification of N -acetyl- l -tyrosine ethyl ester with 1-propanol catalyzed by trypsin supported on MCM-41 (Figure ). The adsorbed enzyme exhibited the same turnover frequency for this reaction as compared to the native enzyme.…”

Section: Biocatalysis With Immobilized Proteinsmentioning

confidence: 99%

Ordered Mesoporous Materials for Bioadsorption and Biocatalysis

2005

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The encapsulation of enzymes and other proteins into inorganic host materials has attracted considerable attention over the past few years. This research has demonstrated that biomolecules immobilized in inorganic matrixes retain their functional characteristics to a large extent. These new materials are of interest for applications as (optically based) biosensors and biocatalysts. We review the growing field of amino acids, vitamins, enzymes, and whole cells adsorbed (immobilized) onto ordered mesoporous silica and carbon molecular sieves. Strategies for the preparation of mesoporous supports and the essential properties of the resulting materials with respect to the envisaged applications are presented. Basic effects of the nature of the adsorption and various aspects of the application of these materials as biosensors, bicatalysts, and for drug release are discussed. Outlook of potential applications and further challenges are also provided.

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Section: Biocatalysis With Immobilized Proteinsmentioning

confidence: 99%

Ordered Mesoporous Materials for Bioadsorption and Biocatalysis

2005

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“…Takahashi et al reported the catalytic activity of horseradish peroxidase immobilized on mesoporous supports in the oxidation of 1,2-diaminobenzene. Gomez et al studied the transesterification of N -acetyl- l -tyrosine ethyl ester with propan-1-ol using trypsin supported on MCM-41 as a catalyst.…”

Section: Introductionmentioning

confidence: 99%

Adsorption of Lysozyme over Mesoporous Molecular Sieves MCM-41 and SBA-15: Influence of pH and Aluminum Incorporation

2004

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The adsorption of lysozyme on the mesoporous molecular sieves MCM-41 and SBA-15 from buffered solutions with different pH values has been studied as a model protein adsorption system. The amount adsorbed depends on the solution pH as well as on the pore volume and the composition of the adsorbent. The adsorption isotherms at pH 6.5 to 10.5 fitted the Langmuir model (type L isotherm), while the isotherms recorded at pH 12 are of the S type. The maximum amount adsorbed was observed for AlSBA-15 at pH 9.6 and amounted to 47.2 µmol/g (580 mg/g). The stability of SBA-15 toward to the buffer solution is higher for SBA-15 as compared to MCM-41, which is probably a consequence of the higher wall thickness of the former material. Diffuse reflectance Fourier transform infrared spectra of the adsorbed lysozyme confirm that the adsorption of the enzyme did not result in denaturation of Lz.

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“…These materials typically possess large surface areas (in excess of 1000 m 2 /g) and large internal pore volumes and have narrow pore size distributions that can be tailored during synthesis. These characteristics have led to the study of mesoporous silica materials in a range of applications where porosity is an important feature, such as catalysis and chromatography. , The large surface area and the controllable pore diameters have also made mesoporous silica attractive as a potential delivery agent for guest molecules, which can be easily adsorbed into their pores by ion exchange or covalent bonding for later release within cells. , Recent studies have focused on the immobilization of metals, proteins, − enzymes, − and drug molecules − into mesoporous silica. Increased uptake capacities (as compared to nonporous materials) have been observed, and subsequent studies involving release of the adsorbed molecules have laid the groundwork for the use of mesoporous materials as delivery agents.…”

Section: Introductionmentioning

confidence: 99%

Adsorption of DNA into Mesoporous Silica

Solberg

Landry²

2006

J. Phys. Chem. B

107

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In these experiments, double-stranded, linear DNA sequences were adsorbed into the pores of spherically shaped acid-prepared mesoporous silica (APMS). The lengths of the sequences were either 760 base pairs or 2000 base pairs. DNA adsorption into the interior of the mesoporous material was confirmed using confocal microscopy of sequences containing fluorescently labeled DNA molecules. Additional characterization with N(2) physisorption and powder X-ray diffraction supported this finding. The extent of adsorption was measured at various concentrations using UV-visible spectrophotometry to establish adsorption isotherms. APMS alone adsorbed a negligible amount of DNA; however, exchanging divalent cations such as Mg(2+) and Ca(2+) into the pores of APMS prior to DNA uptake was found to cause a significant amount of DNA to be adsorbed. Using Na(+) caused a lower amount of DNA to be adsorbed. DNA adsorption was also dependent on the pore diameter of APMS. Adsorption increased upon expansion of the pore size of the metal ion-exchanged material from 34 to 54 A; however, no additional uptake was measured by further increasing the pore size to 100 A. The amount of DNA adsorbed could also be significantly increased by using (aminopropyl)triethoxysilane to covalently link ammonium ions to the surface. Postsynthetic modification of the silica surface with aminopropyl groups increased the maximum DNA adsorption to 15.7 microg/mg silica, for materials with pore diameters of 100 A, which is 2 to 3 times more adsorbed DNA than for metal ion-exchanged material. This indicated that DNA binds more strongly in the presence of the ammonium group compared to the metal counterions. Finally, calculation and comparison of Freundlich and Langmuir constants for these adsorption processes indicate that intermolecular interactions between the DNA molecules within the pores are significant when the effective pore diameter is small, including materials with larger pores that were modified with organosilane.

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Cited by 21 publications

References 9 publications

Ordered Mesoporous Materials for Bioadsorption and Biocatalysis

Ordered Mesoporous Materials for Bioadsorption and Biocatalysis

Adsorption of Lysozyme over Mesoporous Molecular Sieves MCM-41 and SBA-15: Influence of pH and Aluminum Incorporation

Adsorption of DNA into Mesoporous Silica

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