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  • 1.
    Fornara, Andrea
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Chiavarino, Annalisa
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Qin, Jian
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Toprak, Muhammet
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    PLGA-PEG multifunctional nanoparticles for simultaneous drug delivery and visualizationIn: Journal of nanoparticle research, ISSN 1388-0764, E-ISSN 1572-896XArticle in journal (Other academic)
  • 2.
    Fornara, Andrea
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Chiavarino, Annalisa
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Qin, Jian
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Toprak, Muhammet S.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    PLGA-PEG multifunctional nanoparticles for simultaneous drug delivery and imaging by MRI and fluorescence microscopy2012In: Technical Proceedings of the 2012 NSTI Nanotechnology Conference and Expo, NSTI-Nanotech 2012, 2012, p. 4-7Conference paper (Refereed)
    Abstract [en]

    This work deals with the synthesis of multifunctional nanoparticles based on biocompatible di-block copolymer (PLGA-PEG) via an emulsion-evaporation method. To enable their visualization, these nanoparticles can be loaded with iron oxide nanoparticles for Magnetic Resonance Imaging (MRI) and/or quantum dots for fluorescent microscopy. A therapeutic agent, Indomethacin, can also be loaded and released. The influence of synthesis parameters on nanoparticle size (in the range 70-150 nm) has been controlled to achieve specific cellular interactions avoiding possible immuno-response. These multifunctional nanoparticles possess excellent photoemission properties for fluorescent microscopy and enhanced contrast efficiency for T 2 MRI imaging compared to available agents used today. In-vitro experiments confirm the low cytotoxicity of such nanoparticles and their excellent visualization properties by MRI and fluorescence microscopy in cells and biological tissues.

  • 3.
    Fornara, Andrea
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Qin, Jian
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Laurent, Sophie
    University of Mons.
    Muller, Robert
    University of Mons.
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Bifunctional polylactide coated iron oxide nanoparticles for drug delivery and MRI contrast enhancementIn: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095Article in journal (Other academic)
  • 4.
    Fornara, Andrea
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Recalenda, Alberto
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Qin, Jian
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Sugunan, Abhilash
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Fei, Ye
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Laurent, Sophie
    University of Mons.
    Muller, Robert
    University of Mons.
    Zou, Jing
    University of Tampere.
    Usama, Abo-RAmadan
    University of Helsinki.
    Toprak, Muhammet
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Polymeric/inorganic multifunctional nanoparticles for simultaneous drug delivery and visualization2010In: Materials Research Society Symposium Proceedings, ISSN 0272-9172, E-ISSN 1946-4274, Vol. 1257Article in journal (Refereed)
    Abstract [en]

    Nanoparticles consisting of different biocompatible materials are attracting a lot of interest in the biomedical area as useful tools for drug delivery, photo-therapy and contrast enhancement agents in MRI, fluorescence and confocal microscopy. This work mainly focuses on the synthesis of polymeric/inorganic multifunctional nanoparticles (PIMN) based on biocompatible di-block copolymer poly(L,L-lactide-co-ethylene glycol) (PLLA-PEG) via an emulsion-evaporation method. Besides containing a hydrophobic drug (Indomethacin), these polymeric nanoparticles incorporate different visualization agents such as superparamagnetic iron oxide nanoparticles (SPION) and fluorescent Quantum Dots (QDs) that are used as contrast agents for Magnetic Resonance Imaging (MRI) and fluorescence microscopy together. Gold Nanorods are also incorporated in such nanostructures to allow simultaneous visualization and photodynamic therapy. MRI studies are performed with different loading of SPION into PIMN, showing an enhancement in T2 contrast superior to commercial contrast agents. Core-shell QDs absorption and emission spectra are recorded before and after their loading into PIMN. With these polymeric/inorganic multifunctional nanoparticles, both MRI visualization and confocal fluorescence microscopy studies can be performed. Gold nanorods are also synthesized and incorporated into PIMN without changing their longitudinal absorption peak usable for lased excitation and phototherapy. In-vitro cytotoxicity studies have also been performed to confirm the low cytotoxicity of PIMN for further in-vivo studies.

  • 5.
    Fornara, Andrea
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Vogt, Carmen
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Khartsev, Sergiy
    KTH, School of Information and Communication Technology (ICT), Material Physics, Material Physics, MF.
    Li, Shanghua
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Qin, Jian
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Toprak, Muhammet
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Grishin, Alexander
    KTH, School of Information and Communication Technology (ICT), Material Physics, Material Physics, MF.
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Synthesis, characterization and magneto-optical properties of transparent magnetic PMMA/nanoparticles compositeManuscript (preprint) (Other academic)
  • 6.
    Li, Shanghua
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Liang, Yibin
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Qin, Jian
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Toprak, Muhammet
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Template electrodeposition of ordered bismuth telluride nanowire arrays2009In: Journal of Nanoscience and Nanotechnology, ISSN 1533-4880, E-ISSN 1533-4899, Vol. 9, no 2, p. 1543-1547Article in journal (Refereed)
    Abstract [en]

    Thermoelectric bismuth telluride nanowire arrays have been synthesized by direct-current electrodeposition into porous anodic alumina membranes both galvanostatically and potentiostatically. The as-synthesized Bi2Te3 nanowire arrays are highly ordered in large area, stoichiometric, uniform, with high aspect ratio (above 100) and high filling ratio (>90%) of the membrane. The effects of different electrochemical deposition parameters on crystal structures, morphology and composition have been investigated. Field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) have been used to characterize the physical and chemical properties of the nanowires.

  • 7.
    Li, Shanghua
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Qin, Jian
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Fornara, Andrea
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Toprak, Muhammet S.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Kim, Do Kyung
    Synthesis and magnetic properties of bulk transparent PMMA/Fe-oxide nanocomposites2009In: Nanotechnology, ISSN 0957-4484, E-ISSN 1361-6528, Vol. 20, no 18Article in journal (Refereed)
    Abstract [en]

    PMMA/Fe-oxide nanocomposites are fabricated by a chemical method. Monodispersed Fe-oxide nanoparticles are well dispersed in the PMMA matrix by in situ polymerization, resulting in a bulk transparent polymeric nanocomposite. The magnetic behavior of the PMMA/Fe-oxide nanocomposites is investigated. The transparent PMMA/Fe-oxide nanocomposite has potentially interesting magneto-optic applications without compromising the advantages of a lightweight, noncorrosive polymeric material with very high transparency even for bulk samples.

  • 8.
    Okoli, Chuka
    et al.
    KTH, School of Biotechnology (BIO), Environmental Microbiology. KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Fornara, Andrea
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Qin, Jian
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Toprak, Muhammet S.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Dalhammar, Gunnel
    KTH, School of Biotechnology (BIO), Environmental Microbiology.
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Rajarao, Gunaratna
    KTH, School of Biotechnology (BIO), Environmental Microbiology.
    Characterization of Superparamagnetic Iron Oxide Nanoparticles and Its Application in Protein Purification2011In: Journal of Nanoscience and Nanotechnology, ISSN 1533-4880, E-ISSN 1533-4899, Vol. 11, no 11, p. 10201-10206Article in journal (Refereed)
    Abstract [en]

    The application of surface modified magnetic adsorbent particles in combination with magnetic separation techniques has received considerable awareness in recent years. There is a particular need in protein purification and analysis for specific, functional and generic methods of protein binding on solid supports. Nanoscale superparamagnetic iron oxide particles have been used to purify a natural coagulant protein extracted from Moringa oleiferaseeds. Spectrophotometric analysis of the coagulant protein was performed using synthetic clay solution as substrate. Protein binding with carboxyl and silica surface modified superparamagnetic iron oxide nanoparticles (SPION) were compared with the known carboxyl methyl cellulose (CMC) beads of ∼1 m. SPION modified with carboxyl surface showed higher binding capacity towards the coagulant protein compared to the CMC beads. The high surface area to volume ratio of the carboxyl-coated SPION resulted in high binding capacity and rapid adsorption kinetics of the crude protein extract. The purification and molecular weight of coagulant protein is analyzed by SDS-PAGE. This approach utilizes the most efficient, feasible and economical method of coagulant protein purification and it can also be applicable to other proteins that possess similar properties.

  • 9. Poe, Dennis
    et al.
    Zou, Jing
    Zhang, Weikai
    Qin, Jian
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Ramadan, Usama Abo
    Fornara, Andrea
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Pyykkö, Ilmari
    MRI of the Cochlea with Superparamagnetic Iron Oxide Nanoparticles Compared to Gadolinium Chelate Contrast Agents in a Rat Mode2009In: European Journal of Nanomedicine, ISSN 1662-5986, Vol. 2, no 2, p. 29-36Article in journal (Refereed)
  • 10.
    Qin, Jian
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Environment-Sensitive Multifunctional Drug Delivery Systems2010Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Drug delivery systems (DDS) with multiple functionalities such as environment-sensitive drug release mechanisms and visualization agents have motivated the biomedical community as well as materials chemists for more than a decade. This dissertation is concerned with the development of nanoparticles for multifunctional DDS  to tackle several crucial challenges in these complex systems, including polymeric nanospheres which respond to temperature change, superparamagnetic iron oxide nanoparticles/polymeric composite for magnetic resonance imaging contrast agents and drug carriers, immunoresponse of nanomaterials and injectable magnetic field sensitive ferrogels.

    The biocompatible and biodegradable polylactide (PLA) was employed as matrix materials for polymeric nanosphere-based DDS. The thermosensitive polymeric nanospheres have been constructed through a “modified double-emulsion method”. The inner shell containing the thermosensitive poly(N-isopropylacrylamide) (PNIPAAm) undergoes a “hydrophilic-to-hydrophobic” phase transition around the human body temperature. The sensitivity of the polymer to the temperature can facilitate drug release at an elevated temperature upon administration. In addition, gold nanoparticles were assembled on the dual-shell structure to form a layer of gold shell. The cell viability was found to be enhanced due to the gold layer. The immunoresponse of the gold nanoparticles has been considered even if no acute cytotoxicity was observed.

    Imaging is another functionality of multifunctional DDS. This work focuses on magnetic resonance imaging (MRI) and involves synthesis and surface modification of superparamagnetic iron oxide nanoparticles (SPIONs) for contrast agents. The SPIONs have been prepared through a high temperature decomposition method. Surface modification was carried out in different ways. Poly(L,L-lactide) (PLLA) was grafted on SPIONs through surface-initiated ring-opening polymerization. The hydrophobic model drug indomethacin was loaded in the PLLA layer of the composite particles. For biomedical applications, it is essential to modify the hydrophobic particles so that they can be dispersed in physiological solutions. A series of protocols including using small charged molecules and amphiphilic polymers has been established. Pluronic F127 (PF127), a triblock copolymer was applied as a phase transfer reagent. Most interestingly, PF127@SPIONs show remarkable efficacy as T2 contrast agents. The PF127@SPIONs have been successfully applied to image the cochlea in a rat model. As another phase transfer reagent, poly(maleic anhydride-alt-octadecene)-graft-PNIPAAm (PMAO-graft-PNIPAAm) was created for surface modification of SPIONs. This new copolymer provides the modified SPIONs with thermosensitivity together with water-dispersibility.

    As another form of DDS, ferrogel made of PF127 copolymer and SPIONs was developed. Gelation process depends on the temperature of the SPIONs/PF127 mixture. This property makes it possible to use the ferrogel as an injectable drug carrier. Unlike other ferrogels based on crosslinked polymeric network, the PF127 ferrogel can entrap and release hydrophobic drugs. Application of an external magnetic field is found to enhance the drug release rate. This property can find application in externally stimulated local drug release applications.

  • 11.
    Qin, Jian
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Nanoparticles for multifunctional drug delivery systems2007Licentiate thesis, comprehensive summary (Other scientific)
    Abstract [en]

    Multifunctional drug delivery systems incorporated with stimuli-sensitive drug release, magnetic nanoparticles and magnetic resonance (MR) T2 contrast agents is attracting increasing attention recently. In this thesis, works on polymer nanospheres response to temperature change, superparamagnetic iron oxide nanoparticles (SPION)/polymeric composite materials for MR imaging contrast agents are summarized.

    A “shell-in-shell” polymeric structure has been constructed through a “modified double-emulsion method”. Thermosensitive inner shell is comprised of poly(N-isopropylacrylamide) which undergoes phase transition at body temperature. Such a feature could facilitate drug release at an elevated temperature upon administration. Furthermore, the dual-shell structure is covered by a layer of gold nanoparticles. According to the cytotoxicity tests, the biocompatibility is shown to be enhanced due to the layer of gold.

    SPION have been prepared using a high temperature decomposition method. Particle growth of SPION is monitored by transmission electron microscope and synchrotron X-ray diffraction. Poly(L,L-lactide)@SPION (PLLA@SPION) composite particles have been prepared through surface-initiated ring-opening polymerization which has been developed in our lab. For biomedical applications, it is essential to transfer the particles to physiological solutions from organic solutions. Phase transfer of SPION has been carried out by utilizing small molecules. Stability at the neutral pH is of large concern for such transfer systems. A novel phase transfer agent, Pluronic F127 (PF127), a triblock copolymer has been applied and the stability of the aqueous PF127@oleic acid (OA)@SPION solution has been greatly enhanced over a broad pH range. Most interestingly, PF127@OA@SPION show remarkable efficacy as T2 contrast agents as indicated by relaxometric measurements compared with commercially available products.

  • 12.
    Qin, Jian
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Asempah, Isaac
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Laurent, Sophie
    Department of General Organic and Biomedical Chemistry, NMR and Molecular Imaging Laboratory, University of Mons-Hainaut.
    Fornara, Andrea
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Muller, Robert N.
    Department of General Organic and Biomedical Chemistry, NMR and Molecular Imaging Laboratory, University of Mons-Hainaut.
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Injectable Superparamagnetic Ferrogels for Controlled Release of Hydrophobic Drugs2009In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 21, no 13, p. 1354-1357Article in journal (Refereed)
    Abstract [en]

    A ferrogel for magnetically controlled release of drugs is prepared by integration of superparamagnetic iron oxide nanoparticles and Pluronic F127 gels. The hydrophobic drug indomethacin is loaded in the ferrogel owing to the oil-in-water micellar structure. The characteristic solgel transition property renders the ferrogel an injectable drug carrier that will be, in principle, free from surgical implant procedure.

  • 13.
    Qin, Jian
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Jo, Suk
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Coating Nanocrystals with Amphiphilic Thermosensitive Copolymers2009In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 48, no 42, p. 7845-7849Article in journal (Refereed)
    Abstract [en]

    Well-dressed: A new method was developed to produce thermosensitive nanocrystals (NCs) by coating the NCs with an amphiphilic copolymer consisting of poly(maleic anhydride-alt-1-octadecene) (PMAO) and poly(N-isopropylacrylamide) (PNIPAAm; see photograph of coated Fe3O4 NCs at 20 °C and 40 °C). The method is general for all hydrophobic NCs produced by thermolysis.

  • 14.
    Qin, Jian
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Jo, Yun Suk
    Ihm, Jong Eun
    Kim, Do Kyung
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Thermosensitive nanospheres with a gold layer revealed as low-cytotoxic drug vehicles2005In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 21, no 20, p. 9346-9351Article in journal (Refereed)
    Abstract [en]

    In this paper, the positive effect of a gold layer on cell viability is demonstrated by examining the results given by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfop henyl)-2H-tetrazolium (MTS) assay and two-color cell fluorescence viability (TCCV) assay. These cytotoxicity tests were performed with human cervical adenocarcinoma cells (HeLa cell line) and transformed African green monkey kidney fibroblast cells (Cos-7 cell line). To fabricate the nanostructures as drug vehicles, first, poly((L),(L)-lactidec-co-ethylene glycol) (PLLA-PEG) and poly(N-isopropylacrylamide-co-(D),(D)-lactide) (PNIPAAm-PDLA) were synthesized, and then two kinds of thermosensitive nanospheres comprising "shell-in-shell" structures without a gold layer (PLLA-PEG@PNIPAAm-PDLA) and with a gold layer (Au@PLLA-PEG@PNIPAAmPDLA) were constructed by a modified double-emulsion method (MDEM). Both of them displayed a unique thermosensitive character exhibiting the lower critical solubility temperature (LCST) at 36.7 degrees C which was confirmed by LTV-vis spectroscopy and differential scanning calorimetry (DSC). The release profiles of entrapped bovine serum albumin (BSA) were monitored at 22 and 37 degrees C, respectively, to reveal the thermal dependence on the release rate. In cell viability tests, both PLLA-PEG@PNIPAAm-PDLA and Au@PLLAPEGCd)PNIPAAm-PDLA showed excellent cell viability, and furthermore, Au@PLLA-PEG@PNIPAAmPDLA, particularly at high doses, exhibited more enhanced cell viability than PLLA-PEGCa)PNTPAAm-PDLA. This effect is mainly attributed to the gold layer which binds the protein molecules first and consequently facilitates transmembrane uptake of essential nutrients in the cell media, resulting in favorable cell proliferation.

  • 15.
    Qin, Jian
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Laurent, S.
    Jo, Y. S.
    Roch, A.
    Mikhaylova, M.
    Bhujwalla, Z. M.
    Muller, R. N.
    Mohammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    A high-performance magnetic resonance imaging T2 contrast agent2007In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 19, no 14, p. 1874-1878Article in journal (Refereed)
    Abstract [en]

    A high-performance magnetic resonance imaging T-2 contrast agent has been prepared via phase transfer of hydrophobic superparamagnetic iron oxide nanoparticles (SPIONs) to an aqueous solution by using Pluronic F127 copolymers. As seen in the figure, a hierarchical structure of the surface coating is formed and proven to be a crucial characteristic to enhance not only water dispersibility, but also the efficacy as a T-2 contrast agent.

  • 16.
    Qin, Jian
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Nogués, Josep
    Mikhaylova, Maria
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Roig, Anna
    Munõz, Juan S.
    Muhammed, Mamoun
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Differences in the Magnetic Properties of Co, Fe and Ni 250-300 nm Wide Nanowires Electrodeposited in Amorphous Anodized Alumina Templates2005In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 17, no 7, p. 1829-1834Article in journal (Refereed)
    Abstract [en]

    Anodized alumina membranes (AAMs) were synthesized by a three-step electrochemical anodization of aluminum. The anodization results in a hexagonally pseudo-ordered 2D array of nanochannels. The AAMs were used as templates to grow Ni, Co, Fe nanowires, with diameters in the range of 250-300 nm, by electrodeposition. The AAM appears to be amorphous, while the metal nanowires are polycrystalline. The angular dependence of the coercivity, HC, of the Ni nanowires presents a smooth variation from a moHC = 5.5 mT when the field is applied perpendicular to the wires to moHC = 53 mT when the field is applied parallel to them. However, the Co and Fe nanowires exhibit a peak in the angular dependence of HC for fields applied close to the AAM plane (i.e. perpendicular to the wires). The competition between shape anisotropy and dipolar interaction between the nanowires seems to be responsible for the difference in magnetic behavior between the different metals.

  • 17. Salazar-Alvarez, G.
    et al.
    Qin, Jian
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Sepelak, V
    Bergmann, I
    Vasilakaki, M
    Trohidou, N.
    Ardisson, D.
    Macedo, A.
    Mikhaylova, M.
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Baro, D
    Nogues, J.
    Cubic versus spherical magnetic nanoparticles: The role of surface anisotropy2008In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 130, no 40, p. 13234-13239Article in journal (Refereed)
    Abstract [en]

    The magnetic properties of maghemite (gamma-Fe2O3) cubic and spherical nanoparticles of similar sizes have been experimentally and theoretically studied. The blocking temperature, TB, of the nanoparticles depends on their shape, with the spherical ones exhibiting larger TB. Other low temperature properties such as saturation magnetization, coercivity, loop shift or spin canting are rather similar. The experimental effective anisotropy and the Monte Carlo simulations indicate that the different random surface anisotropy of the two morphologies combined with the low magnetocrystalline anisotropy of gamma-Fe2O3 is the origin of these effects.

  • 18.
    Sugunan, Abhilash
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Jafri, S. Hassan M.
    Qin, Jian
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Blom, Tobias
    Toprak, Muhammet S.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Leifer, Klaus
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Low-temperature synthesis of photoconducting CdTe nanotetrapods2010In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 20, no 6, p. 1208-1214Article in journal (Refereed)
  • 19. Thaler, Marlene
    et al.
    Roy, Soumen
    Qin, Jian
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Bitsche, Mario
    Glueckert, Rudolf
    Fornara, Andrea
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Salvenmoser, Willi
    Rieger, Gunde
    Visualization and Analysis of Superparamagnetic Ferrogels in the Inner Ear by Light Microscopy and Energy Filtred TEM: a promising approach for advanced local drug deliveryIn: Journal of Microscopy, ISSN 0022-2720, E-ISSN 1365-2818Article in journal (Other academic)
  • 20.
    Thaler, Marlene
    et al.
    Carl Zeiss NTS GmbH.
    Roy, Suomen
    Medical University of Innsbruck.
    Fornara, Andrea
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Bitsche, Mario
    Medical University of Innsbruck.
    Qin, Jian
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Salvenmoser, Willi
    University of Innsbruck.
    Rieger, Gunde
    Medical University of Innsbruck.
    Schrott Fischer, Anneliese
    Medical University of Innsbruck.
    Glueckert, Rudolf
    Medical University of Innsbruck.
    Visualization and Analysis of Superparamagnetic Iron Oxide Nanoparticles in the Inner Ear by Light Microscopy and Energy Filtered TEM2011In: Nanomedicine: Nanotechnology, Biology, and Medicine, ISSN 1549-9634, Vol. 7, no 3, p. 360-369Article in journal (Refereed)
    Abstract [en]

    Nanoparticles as potential carriers for local drug transfer are an alternative to systemic drug delivery into the inner ear. We report on the first in vitro tests of a new ferrogel consisting of superparamagnetic iron oxide nanoparticles (SPIONs) and a Pluronic (R) F127 (PF127) copolymer. Pluronic copolymers possess a unique viscosity-adjustable property that makes PF127 gels easy to handle compared to conventional cross-linked hydrogels. This ferrogel was successfully tested in cadaver human temporal bones as well as in organotypic explant cultures of mouse inner ears. SPIONs were identified by light microscopy and localized with different imaging modes in energy-filtered transmission electron microscopy. Our approach shows a promising possibility to use iron oxide nanoparticles, which are suitable for visualization and characterization at both the light- and electron-microscopic levels.

    From the Clinical Editor: The authors report the first in vitro tests of a new ferrogel consisting of superparamagnetic iron oxide nanoparticles (SPIONs) and a Pluronic (R) F127 (PF127) copolymer for drug delivery in the inner ear, demonstrasting a promising possibility to use iron oxide nanoparticles, which are suitable for visualization and characterization at both the light- and electron-microscopic levels.

  • 21. Vallhov, H.
    et al.
    Qin, Jian
    KTH, School of Information and Communication Technology (ICT), Material Physics (Closed 20120101), Functional Materials, FNM (Closed 20120101).
    Johansson, S.
    Muhammed, Mamoun Ali
    KTH, School of Information and Communication Technology (ICT), Material Physics (Closed 20120101), Functional Materials, FNM (Closed 20120101).
    Gabrielsson, S.
    Scheynius, A.
    The effect of gold nanoparticles on dendritic cells2006In: 2006 NSTI Nanotechnology Conference and Trade Show: NSTI Nanotech 2006 Technical Proceedings, 2006Conference paper (Refereed)
    Abstract [en]

    Gold is recognized as one of the most biocompatible and stable materials, and has been used for many years as a medical agent, among others in the form of salt for the treatment of rheumatoid arthritis [1]. More recent biological applications have been focusing on using gold nanoparticles for drug and gene delivery [2], or as a photothermal agent causing highly localized heating applicable in cancer therapy [3]. There is however very little information available concerning what influence such particles have on the immune system, e.g. on dendritic cells (DCs). DCs are present throughout the human body but are particularly localized at antigen-exposed sites, such as the skin. They are the most efficient type of antigen presenting cells having a capacity both to initiate primary and secondary immune responses, by expressing cytokines, MHC and co-stimulatory molecules such as CD80, CD83 and CD86 [4-5]. DCs decide whether an immune response should be initiated and are able to affect the development of T-helper cells into Treg-, Th1- or Th2-cells depending on their cytokines produced and their expression of co-stimulatory molecules [6]. We addressed the question whether spherical gold nanoparticles of 6 nm in diameter affect DCs, looking at morphology, viability, expression of cytokines and of co-stimulatory and antigen presenting molecules. This was assessed by using human monocyte derived DCs (myeloid DCs) and peripheral blood mononuclear cells from healthy blood donors together with gold nanoparticles [7], and various techniques including light microscopy, flow cytometry and ELISpot. After having overcome aggregation problems of gold nanoparticles by stabilizing with human serum albumin (HSA) and developed methods to produce nanoparticles with low lipopolysaccharide (LPS) contamination, experiments revealed that both morphology and viability were not affected by the gold nanoparticles. The expression of CD80, CD83, CD86 and MHC class II was only to a minor degree up-regulated after 6 and 24 h, and CD40 and MHC class I was not affected, which indicates biocompatibility of gold nanoparticles. This is further supported by low or no expression of the cytokines IL-10, IL-12 and IFN-alpha. HSA by itself did not have an effect on the DCs. In conclusion, gold nanoparticles of 6 nm in diameter are highly unlikely to initiate a danger signal to the immune system through the dendritic cells, and have therefore the potential to be used as inert carriers in biomedical applications.

  • 22. Vallhov, Helen
    et al.
    Qin, Jian
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Johansson, Sara M.
    Ahlborg, Niklas
    Muhammed, Mamoun A.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Scheynius, Annika
    Gabrielsson, Susanne
    The importance of an endotoxin-free environment during the production of nanoparticles used in medical applications2006In: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 6, no 8, p. 1682-1686Article in journal (Refereed)
    Abstract [en]

    We investigated the effect of spherical gold nanoparticles on immature dendritic cells (DCs). Conventionally produced nanoparticles had a maturating effect on the DCs-a result of lipopolysaccharide (LPS) contamination. By modification of the production process, low-LPS particles were obtained, which had practically no effect on phenotypic maturation or cytokine production of the DCs. Our findings emphasize the importance of high purity in the production of nanoparticles, since possible contaminants may interfere with the assessment of biological/medical effects. They also highlight that nanoparticles can function as carriers of immune modulating contaminants.

  • 23.
    Wang, Xiaodi
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Ma, Ying
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Sugunan, Abhilash
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Qin, Jian
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Toprak, Muhammet
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Zhu, Bin
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Synthesis of uniform quasi-octahedral CeO2 mesocrystals via a surfactant-free route2011In: Journal of nanoparticle research, ISSN 1388-0764, E-ISSN 1572-896X, Vol. 13, no 11, p. 5879-5885Article in journal (Refereed)
    Abstract [en]

    A facile surfactant-free nonaqueous method is presented to prepare uniform quasi-octahedral ceria, CeO 2 , mesocrystals, in which only Ce(NO 3 ) 3 and octanol were used as the reactants at a reaction temperature of 150 °C. CeO 2 sample synthesized using this technique consists of well-dispersed quasi-octahedrons and exhibits an uniform size and morphology. Based on structural characterization, it is proposed that the CeO 2 mesostructure was formed by self-assembly of primary nanocrystals based on unique 3D oriented-attachment mechanism. Optical characterization exhibited a strong quantum confinement, revealing small size of primary nanocrystals. The thermal stability and UV–Vis study reveal CeO 2 mesocrystal has various potential for high temperature applications and optical apparatus applications.

  • 24. Yao, Mingguang
    et al.
    Stenmark, Patrik
    Abou-Hamad, Edy
    Nitze, Florian
    Qin, Jian
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Goze-Bac, Christophe
    Wågberg, Thomas
    Confined adamantane molecules assembled to one dimension in carbon nanotubes2011In: Carbon, ISSN 0008-6223, E-ISSN 1873-3891, Vol. 49, no 4, p. 1159-1166Article in journal (Refereed)
    Abstract [en]

    We have encapsulated adamantane (C10H16) in single- and multi-walled carbon nanotubes. Adamantane is a high symmetry cage like molecule with point group symmetry T-d and can be considered as a hydrogen-terminated diamond fragment. We confirmed and identified the successful filling by high resolution transmission electron microscopy, C-13 nuclear magnetic resonance, infrared and Raman spectroscopy. C-13 nuclear magnetic resonance of the adamantane filled nanotubes reveals that the adamantane molecules stop rotating after encapsulation. A blue-shift of the Raman active radial breathing modes of the carbon nanotubes supports this and suggests a significant interaction between encapsulated adamantane molecules and the single wall nanotubes. The encapsulated adamantane molecules exhibit red shifted infrared C-H vibration modes which we assign to a slight elongation of the C-H bonds. We observe both a nanotube diameter dependence of the adamantane filling ratio and a release rate of adamantane from the CNTs that depends on the CNT diameters.

  • 25.
    Ye, Fei
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Laurent, Sophie
    Fornara, Andrea
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Astolfi, Laura
    Qin, Jian
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Roch, Alain
    Martini, Alessandro
    Toprak, Muhammet
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Muller, Robert N.
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Uniform mesoporous silica coated iron oxide nanoparticles as a highly efficient, nontoxic MRI T2 contrast agent with tunable proton relaxivities2012In: Contrast Media & Molecular Imaging, ISSN 1555-4309, E-ISSN 1555-4317, Vol. 7, no 5, p. 460-468Article in journal (Refereed)
    Abstract [en]

    Monodisperse mesoporous silica (mSiO2) coated superparamagnetic iron oxide (Fe3O4@mSiO2) nanoparticles (NPs) have been developed as a potential magnetic resonance imaging (MRI) T2 contrast agent. To evaluate the effect of surface coating on MRI contrast efficiency, we examined the proton relaxivities of Fe3O4@mSiO2 NPs with different coating thicknesses. It was found that the mSiO2 coating has a significant impact on the efficiency of Fe3O4 NPs for MRI contrast enhancement. The efficiency increases with the thickness of mSiO2 coating and is much higher than that of the commercial contrast agents. Nuclear magnetic resonance (NMR) relaxometry of Fe3O4@mSiO2 further revealed that mSiO2 coating is partially permeable to water molecules and therefore induces the decrease of longitudinal relaxivity, r1. Biocompatibility evaluation of various sized (ca. 3595 nm) Fe3O4@mSiO2 NPs was tested on OC-k3 cells and the result showed that these particles have no negative impact on cell viability. The enhanced MRI efficiency of Fe3O4@mSiO2 highlights these coreshell particles as highly efficient T2 contrast agents with high biocompatibility.

  • 26.
    Ye, Fei
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics (Closed 20120101), Functional Materials, FNM (Closed 20120101).
    Qin, Jian
    KTH, School of Information and Communication Technology (ICT), Material Physics (Closed 20120101), Functional Materials, FNM (Closed 20120101).
    Toprak, Muhammet S.
    KTH, School of Information and Communication Technology (ICT), Material Physics (Closed 20120101), Functional Materials, FNM (Closed 20120101).
    Muhammed, Mamoun
    KTH, School of Engineering Sciences (SCI), Applied Physics, Functional Materials, FNM.
    Multifunctional core-shell nanoparticles: superparamagnetic, mesoporous, and thermosensitive2011In: Journal of nanoparticle research, ISSN 1388-0764, E-ISSN 1572-896X, Vol. 13, no 11, p. 6157-6167Article in journal (Refereed)
    Abstract [en]

    Multifunctional core-shell composite nanoparticles (NPs) have been developed by the combination of three functionalities into one entity, which is composed of a single Fe3O4 NP as the magnetic core, mesoporous silica (mSiO2) with cavities as the sandwiched layer, and thermosensitive poly(N-isopropylacrylamide-co-acrylamide) (P(NIPAAm-co-AAm)) copolymer as the outer shell. The mSiO2-coated Fe3O4 NPs (Fe3O4@mSiO2) are monodisperse and the particle sizes were varied from 25 to 95 nm by precisely controlling the thickness of mSiO2-coating layer. The P(NIPAAm-co-AAm) were then grown onto surface-initiator-modified Fe3O4@mSiO2 NPs through free radical polymerization. These core-shell composite NPs (designated as Fe3O4@mSiO2@P(NIPAAm-co-AAm)) were found to be superparamagnetic with high r2 relaxivity. To manipulate the phase transition behavior of these thermosensitive polymer-coated NPs for future in vivo applications, the characteristic lower critical solution temperature (LCST) was subtly tuned by adjusting the composition of the monomers to be around the human body temperature (i.e. 37 °C), from ca. 34 to ca. 42 °C. The thermal response of the core-shell composite NPs to the external magnetic field was also demonstrated. Owing to their multiple functionality characteristics, these porous superparamagnetic and thermosensitive NPs may prove valuable for simultaneous magnetic resonance imaging (MRI), temperature-controlled drug release, and temperature-programed magnetic targeting and separation applications.

  • 27.
    Ye, Fei
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Vallhov, Helen
    Clinical Allergy Research Unit, Department of Medicine, Karolinska Institute and University Hospital Solna, Sweden.
    Qin, Jian
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Daskalaki, Evangelia
    Clinical Allergy Research Unit, Department of Medicine, Karolinska Institutet and Universty Hospital Solan, Sweden.
    abhilash, Sugunan
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Toprak, Muhammet S.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Fornara, Andrea
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Gabrielsson, Susanne
    Clinical Allergy Research Unit, Department of Medicine, Karolinska Institutet and Universty Hospital Solan, Sweden.
    Scheynius, Annika
    Clinical Allergy Research Unit, Department of Medicine, Karolinska Institutet and Universty Hospital Solan, Sweden.
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Synthesis of high aspect ratio gold nanorods and their effects on human antigen presenting dendritic cells2011In: International Journal Of Nanotechnology, ISSN 1475-7435, Vol. 8, no 8-9, p. 631-652Article in journal (Refereed)
    Abstract [en]

    High aspect ratio (AR) gold nanorods (NRs) attract great interest for biomedical applications due to their novel physicochemical properties. Here, we report a facile method for preparation of high AR gold NRs through a seedless surfactant-mediated protocol with the additive of nitric acid. High-resolution transmission electron microscopy studies showed that the concentration of nitric acid has great effects on the crystal structures of the initially formed nuclei and consequently the growth of gold NRs. A mechanism based on the effect of nitrate ions on surfactant micelle elongation and Ostwald ripening process is proposed for the growth of high AR gold NRs. The biocompatibility of high AR NRs was evaluated on primary human monocyte derived dendritic cells (MDDCs), and compared with that of spherical gold nanoparticles (NPs) and low AR NRs. Low AR (similar to 4.5) gold NRs induced considerable cell death due to CTAB, while spherical gold NPs (7 nm) and high AR (similar to 21) gold NRs showed no or minor effects on viability and immune regulatory markers, which supports the further development of high AR gold NRs for medical applications.

  • 28.
    Zhou, Jing
    et al.
    University of Tampere.
    Zhang, Weikai
    University of Tampere.
    Poe, Dennis
    University of Tampere.
    Qin, Jian
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Fornara, Andrea
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Zhang, Ya
    University of Tampere.
    Ramadan, Usama
    University of Helsinki.
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Pyykkö, Ilmari
    University of Tampere.
    MRI manifestation of novel superparamagnetic iron oxide nanoparticles in the rat inner ear2010In: Nanomedicine, ISSN 1743-5889, Vol. 5, no 5, p. 739-754Article in journal (Refereed)
    Abstract [en]

    Aim: Superparamagnetic iron oxide nanoparticles hierarchically coated with oleic acid and Pluronic F127 copolymers (POA@SPION) have shown exceptional 12 contrast enhancement. The aim of the present work was to investigate the MRI manifestation of POA@SPION in the inner ear. Materials & methods: A total of 26 male Wister rats were selected for testing POA@SPION administered through intracochlear, intratympanic and intravenous routes. MRI was performed with a 4.7 T MR scanner. Results & conclusion: POA@SPION can be introduced into the perilymph space, after which it becomes widely distributed and can demonstrate the integrity of the perilymph-endolymph barrier. Positive highlighting of the endolymph compartment against the darkened perilymph was visualized for the first time. POA@SPION passed through the middle-inner ear barriers in only small amounts, but stayed in the perilymph for 3 days. They did not traverse the blood-perilymph barrier or blood-endolymph barrier. The inner ear distribution of POA@SPION was confirmed by histology. POA@SPION is a promising T2 negative contrast agent.

1 - 28 of 28
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