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Östermalm, Sweden

Xia X.,TU Munich | Xia X.,Nanologica AB | Metwalli E.,TU Munich | Ruderer M.A.,TU Munich | And 4 more authors.
Journal of Physics Condensed Matter | Year: 2011

Nanostructured diblock copolymer films with embedded magnetic nanoparticles are prepared by solution casting. The diblock copolymer polystyrene-block- polymethylmethacrylate with a fully deuterated polystyrene block of a weight ratio of 0.22 is used as a structure-directing matrix. Maghemite nanoparticles (γ-Fe2O3) are coated with polystyrene and thus have a selective affinity to the minority block of the diblock copolymer. The hybrid film morphology is investigated as a function of nanoparticle concentration. The surface structure is probed with atomic force microscopy and scanning electron microscopy. The inner film structure and the structure at the polymer-substrate interface are detected with grazing incidence small angle neutron scattering (GISANS). Irrespective of the nanoparticle concentration a well developed micro-phase separation structure is present. From the Bragg peaks observed in the GISANS data a linear nanoparticle concentration dependence of the inter-domain spacing of the micro-phase separation structure is determined. The superparamagnetic and blocking behavior can be explained with a generalized Stoner-Wohlfarth-Néel theory which includes either an elastic torque being exerted on the nanoparticles by the field or a broad distribution of anisotropy constants. © 2011 IOP Publishing Ltd.

Zhou C.,Nanologica AB | Kunzmann A.,Karolinska Institutet | Rakonjac M.,Karolinska Institutet | Fadeel B.,Karolinska Institutet | Garcia-Bennett A.,Uppsala University
Nanomedicine | Year: 2012

Background: Mesoporous silica-based particles are of potential interest for the development of novel therapeutic targeted delivery vehicles. Their ability to load and release large quantities of active pharmaceutical products with varying properties, combining controlled and targeted release functions make them unique amongst nanotechnology-based carrier systems. Materials and methods: In this study, nanoporous folic acid-templated materials (NFM-1) were prepared and the synthetic strategies for the control of textural and morphology properties of NFM-1 are described. The potential biocompatibility of NFM-1 particles with different morphology (gyroid shaped, fibers and rod-shaped) was assessed using a panel of human cell lines. Results: The results reveal that NFM-1 morphology has an impact on cell viability such that particles showing higher aspect ratios possess increased cytotoxicity. Conclusion: These studies provide useful information for the development of novel mesoporous materials for biomedical applications, including cell-specific drug delivery. © 2012 Future Medicine Ltd.

Zhou C.,Nanologica AB | Garcia-Bennett A.E.,Nanotechnology and Functional Materials
Journal of Nanoscience and Nanotechnology | Year: 2010

Mesoporous NFM-1 silica with folic acid as template was prepared taking advantage of the supramolecular self-assembly of pterin groups and their abilities to form hexagonal liquid crystal phases. NFM-1 materials with the varied morphologies such as fiber, chiral twisting long-rod, gyroid, and amorphous particles were prepared by varying the amount of the co-structure directing agent, stirring speed and changing pH value of the synthesis. The release kinetics of NFM-1 samples with different morphologies were studied in phosphate buffer with pH = 7.4 in 37 °C under stirring. All the release kinetic curves are fitted by the power law and Higuchi equations. The fitting of the power law equation was separately done as for the released amount up to 60% or 100%. The materials show slow, long-term and sustained release of folic acid from mesoporous NFM-1 silica, which establishes a new foundation for the potential application in drug delivery and bioimaging. Copyright © 2010 American Scientific Publishers.

A method for the preparation of enhanced fluorescent folic acid mesoporous material, multifluorescent mesoporous materials, their novel properties and applications such as: a mesoporous fluorescent composition suitable for printing identification marks on metals, glass, plastic, ceramics, or paper which are visible only when excited by an external radiation; and applications in life science applications such as diagnostic, biodistribution markers, and targeted drug delivery applications.

The present invention relates to a new synthetise for the preparation of mesoporous structures including mesoporous materials with chiral morphologies and mesoporous materials with local or surface chirality. The method can be used for manufacturing controlled drug delivery devices, for example for delivery of folic acid, and fluorescent particles.

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