ORCID Profile
0000-0003-4710-6120
Current Organisation
Swerea KIMAB AB
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Wiley
Date: 20-11-2009
DOI: 10.1002/WNAN.13
Abstract: We present here a study of the controlled release of amino acid‐derived hiphilic molecules from the internal pore structure of mesoporous nanoparticle drug delivery systems with different structural properties, namely cubic and hexagonal structures of various degrees of complexity. The internal pore surface of the nanomaterials presented has been functionalised with amine moieties through a one‐pot method. Release profiles obtained by conductivity measurements are interpreted in terms of specific structural and textural parameters of the porous nanoparticles, such as pore geometry and connectivity. Results indicate that diffusion coefficients are lower by as much 4 orders of magnitude in two‐dimensional structures in comparison to three‐dimensional mesoporous solids. A fast release in turn is observed from mesocaged materials AMS‐9 and AMS‐8, where the presence of structural defects is thought to lead to a slightly lower diffusion coefficient in the latter. We conclude that the use of single or mixed phases of these porous systems can be utilized to provide sustained release over long time periods and expect their use in a variety of formulations. Copyright © 2008 John Wiley & Sons, Inc. This article is categorized under: Therapeutic Approaches and Drug Discovery Nanomedicine for Respiratory Disease
Publisher: Bentham Science Publishers Ltd.
Date: 07-2008
DOI: 10.2174/156720108784911686
Abstract: We present here a detailed study of the controlled release of amino acid derived hiphilic molecules from the internal pore structure of mesoporous nanoparticle drug delivery systems with different structural properties namely cubic and hexagonal structures of various degrees of complexity. The internal pore surface of the nanomaterials presented has been functionalised with amine moieties through a one pot method. Release profiles obtained by Alternating Ionic Current measurements are interpreted in terms of specific structural and textural parameters of the porous nanoparticles such as pore geometry and connectivity. Results indicate that diffusion coefficients are lower by as much as four orders of magnitude in 2-dimensional structures in comparison to 3-dimensional mesoporous solids. A fast release in turn is observed from mesocaged materials AMS-9 and AMS-8 where the presence of structural defects is thought to lead to a slightly lower diffusion coefficient in the latter. Amount of pore wall functionalisation and number of binding sites on the model drug are found to have little effect on the drug release rate.
Publisher: American Chemical Society (ACS)
Date: 16-08-2007
DOI: 10.1021/LA700899S
Abstract: The purpose of this work is to study the kinetics of self-assembly in the formation mechanism of anionic templated mesoporous solids (AMS-n) during the first few seconds of the synthesis as well as to demonstrate the use of alternating ion current (AIC) conductivity measurements to follow the self-assembly in complex hybrid systems. The formation of different AMS-n caged-type mesostructures through the delayed addition of the silica source is demonstrated and explained in terms of the interaction between the co-structure-directing agent (CSDA) and the oppositely charged surfactant headgroup regions. Our findings, supported by transmission electron microscopy, 29Si magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy, dynamic light scattering (DLS) measurements, and powder X-ray diffraction suggest that the interaction of the CSDA with the surfactant headgroup occurs within seconds after its addition to the synthesis gel leading to interaction between the polymerizing CSDAs and the oppositely charged micelle and to an increase in the micelle-CSDA aggregate size. Both DLS and AIC measurements agree that this process occurs within the first 1000 s after addition of the CSDA to the synthesis gel at room temperature. In addition to the mechanistic study it was found that the intermediate materials are comprised of a three-layer entity. Time-dependent 29Si MAS NMR studies reveal that an organo-silica layer forms around the micelles prior to a condensed outer inorganic shell of silica.
Publisher: American Chemical Society (ACS)
Date: 12-03-2009
DOI: 10.1021/LA900105U
Abstract: A new method to investigate the effect of pore geometry on diffusion processes in mesoporous silica nanoparticles and other types of micro- and mesoporous structures is put forward. The method is based on the study of proton diffusion from a liquid surrounding the mesoporous particles into the particle pore system. The proton diffusion properties are assessed for a variety of as-synthesized mesoporous nano- and microparticles with two-dimensional and three-dimensional connectivity. Results show that the diffusion coefficients are higher for the proton absorption process than for the release of surfactant template molecules, and that they overall follow the same trend with the more complex three-dimensional mesocaged particles showing the highest diffusion coefficients. The pore geometry (cylindrical pores versus cage-type pores) and structure connectivity are found to play a key role for the effects observed. The results put forward in the present work should offer a valuable tool in the development of porous nanomaterials in a range of applications including the use as catalysis and separation enhancers in the petrochemical industry, as scaffolds for hydrogen storage, and as drug delivery vehicles for sustained release and gene transfection.
No related grants have been discovered for Ulrika Brohede.