Gerald Brezesinski

Max Planck Institute of Colloids and Interfaces, Potsdam, Brandenburg, Germany

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Publications (334)1015.02 Total impact

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    ABSTRACT: Highly dynamic tubular structures in cells are responsible for exchanges between organelles. Compared with bacterial invasion, the most affordable and least toxic lipids were found in this study to be gentle and safe exogenous stimuli for the triggering of membrane tubules. A specific lipid system was internalized by NIH3T3 cells. Following cellular uptake, the constructed liposomes traveled towards the nucleus in aggregations and were gradually distributed into moving vesicles and tubules in the cytosol. The triggered tubules proceeded, retreated or fluctuated along the cytoskeleton and were highly dynamic, moving quickly (up to several microns per second), and breaking and fusing frequently. These elongated tubules could also fuse with one another, giving rise to polygonal membrane networks. These lipid systems, with the novel property of accelerating intracellular transport, provide a new paradigm for investigating cellular dynamics.
    Scientific Reports 11/2015; 5. DOI:10.1038/srep16559 · 5.58 Impact Factor
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    ABSTRACT: In the present work, we characterize binary lipid mixtures consisting of a three-chain amino-functionalized cationic lipid (DiTT4) with different phospholipids, namely, 1,2-di-(9Z-oleoyl)-sn-glycero-3-phosphoethanolamine (DOPE), 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine (DMPE), or 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC). The mixing behavior was investigated by differential scanning calorimetry (DSC). Additionally, aqueous dispersions of the binary mixtures were characterized by means of dynamic light scattering (DLS), laser Doppler electrophoresis, and transmission electron microscopy (TEM) to get further information about particle size, charge, and shape. The complex formation between different binary lipid mixtures and plasmid DNA (pDNA) was investigated by zeta-(ζ)-potential (laser Doppler electrophoresis) and DLS measurements, and the lipid/DNA complexes (lipoplexes) were screened for efficient DNA transfer (transfection) in cell culture. Finally, efficient lipid compositions were investigated with respect on serum stability. This work provides a detailed characterization of the cationic lipid mixtures as fundament for further research. Efficient gene transfer in presence of serum was demonstrated for selected lipoplexes showing their capability to be used as high-potent gene delivery vehicles.
    Bioconjugate Chemistry 10/2015; DOI:10.1021/acs.bioconjchem.5b00505 · 4.51 Impact Factor
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    ABSTRACT: The use of cationic lipids as gene delivery systems is a basic method in gene therapy. Through ongoing research, lipofection is currently the leader of non-viral vectors in clinical trials. However, in order to unleash the full potential of lipofection further intensive investigations are indispensable. In this study, various lipoplex formulations were compared regarding their ability to bind DNA. To obtain information about a possible premature release of DNA at the cell surface, heparin and chondroitin dependent lipoplex destabilization experiments were carried out. Complementary investigations in cell culture were performed to quantify DNA outside the cell. Additionally, DNase I stability was investigated. In this regard a multitude of methods, namely confocal laser scanning microscopy (CLSM), polymerase chain reaction (PCR), cell culture experiments, ethidium bromide assay, gel electrophoresis, Langmuir-isotherm experiments, infrared reflection absorption spectroscopy (IRRAS), Brewster angle microscopy (BAM), zeta-(ζ)-potential measurements, and dynamic light scattering (DLS), were applied. Although the complexation of DNA is a fundamental step, we show that the DNA release by biological agents (proteoglycans) and an unsuccessful cell attachment are major transfection limiting parameter.
    Journal of Controlled Release 10/2015; 220(Pt A). DOI:10.1016/j.jconrel.2015.10.045 · 7.71 Impact Factor
  • C. Dannehl · G. Brezesinski · H. Möhwald ·
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    ABSTRACT: The interactions of two fragments of the human antimicrobial LL-37 (LL-32 and LL-20) with lipid monolayers at the soft liquid/air interface have been characterized. To model the interaction with mammalian cell membranes, lipid monolayers composed of the zwitterionic DPPC and DOPC were used. To investigate the interaction with bacterial cell membranes, lipid monolayers of anionic DPPG and POPG were used. DPPC and DPPG exhibit a first-order phase transition from the disordered liquid to the ordered condensed state, whereas POPG and DOPC monolayers are in the fluid disordered state at all surface pressures studied. Therefore, the influence of the monolayer phase state on peptide-lipid interactions can be studied. To obtain insight into the peptide structure and their influence on phospholipid membranes, film balance measurements were coupled with surface sensitive Infrared Reflection-Absorption Spectroscopy (IRRAS). The results were compared to CD measurements in bulk. LL-32 is more surface active and can better intercalate into lipid monolayers than LL-20. Even though LL-32 has no cell-selectivity, our results show how the peptide interacts differently with zwitterionic compared to anionic membrane models. The interaction with DPPC monolayers is based on simple intercalation of the peptides between the lipid molecules. However, the peptides bind in a two-step process to DPPG monolayers, which results in a fluidization of the lipid film. This can be related to a membrane thinning.
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    Colloid and Polymer Science 08/2015; DOI:10.1007/s00396-015-3710-9 · 1.87 Impact Factor
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    ABSTRACT: Prussian Blue analogue (PBA) nanoparticles can be self-assembled at air/liquid interfaces to build novel materials with interesting magnetic features. Herein, we study the influence of the size of PBA Cs0.4 Ni[Cr(CN)6 ]0.9 and K0.25 Ni[Fe(CN)6 ]0.75 nanoparticles on the self-assembly behavior by synchrotron X-ray reflectivity. Both nanoparticles show similar Z-potential values. The phospholipid dipalmitoylphosphatidylcholine and the amino surfactant dimethyldioctadecylammonium have been used as Langmuir monolayers to anchor the PBA nanoparticles and study the interplay of forces directing the self-assembly of the nanoparticles at the surfactant/liquid interface. Whereas Cs0.4 Ni[Cr(CN)6 ]0.9 nanoparticles with a diameter of 8 nm form an incomplete layer at the surfactant/water interface, the larger K0.25 Ni[Fe(CN)6 ]0.75 nanoparticles with a diameter of 20 nm generate complete layers that can be stacked to one another. The size of the PBA nanoparticles is the main parameter determining the final arrangement at the air/liquid interface, due to the different extent of interparticle interaction. This study aims at the rationale design of PBA nanoparticles for an effective interfacial self-assembly, ultimately leading to functional materials. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
    ChemPhysChem 07/2015; 16(12). DOI:10.1002/cphc.201500350 · 3.42 Impact Factor
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    ABSTRACT: The aggregation behavior of a cationic lipid, N-[6-amino-1-oxo-1-(N-tetradecylamino)hexan-(2S)-2-yl]-N'-{2-[N,N-bis(2-aminoethyl)amino]ethyl}-2,2-ditetradecylpropandiamide (DiTT4), is investigated in aqueous dispersions at different pH values (5, 7.3, and 10). An unusual aggregation behavior is observed whereby DiTT4 forms bilayer structures at pH 10 and 7.3. At pH 5, rod-like micelles are the dominant aggregate form. The thermotropic and lyotropic behavior is studied using differential scanning calorimetry, small-angle X-ray scattering, and FTIR spectroscopy. In addition, investigations at the air-water interface are performed by recording area-pressure-isotherms and infrared reflection-absorption (IRRA) spectra. Complementary dynamic light scattering experiments and transmission electron microscopy (TEM and cryoTEM) are also used. The ability of DiTT4 to complex plasmid DNA is investigated using fluorescence techniques and zeta potential measurements. Cell culture experiments demonstrate the ability of DiTT4 to enhance plasmid transfer in A549 cells. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
    ChemPhysChem 05/2015; 16(10):2115-2126. DOI:10.1002/cphc.201500188 · 3.42 Impact Factor
  • Dieter Vollhardt · Gerald Brezesinski ·
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    ABSTRACT: Although monoacylglycerol monolayers have been used as highly informative systems, so far general information about their phase behavior and especially that of 1-monostearoyl-rac-glycerol monolayers has been missing. Complemented by the characteristics of the p-A isotherms and the mesoscopic domain topography, the present work focused on Grazing incidence X-ray diffraction (GIXD) measurements of 1-monostearoyl-rac-glycerol monolayers in the accessible temperature and surface pressure range to construct the phase diagram on the basis of reliable two-dimensional lattice structures. Examples for the mesoscopic topography of regularly and irregularly shaped domains obtainable in the first-order main phase transition region at temperatures T > 30°C are presented and discussed on the basis of line tension and geometric considerations. The GIXD results obtained over large pressure interval at 5, 10, 15 and 20 °C indicate impressively that also in the racemic 1-monostearoyl-rac-glycerol monolayer symmetry breaking occurs at low temperatures in a small pressure region where an oblique intermediate (Obl) phase between the NN and NNN tilted orthorhombic phases occurs. The temperature effect on the phase behavior of the 1-monostearoyl-rac-glycerol monolayers is demonstrated by the surface pressure - temperature diagram.
    The Journal of Physical Chemistry C 04/2015; 119(18):150414210803000. DOI:10.1021/acs.jpcc.5b01766 · 4.77 Impact Factor
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    ABSTRACT: The phase behavior of an amphiphilic block copolymer based on a poly(aspartic acid) hydrophilic block and a poly(n-butyl acrylate) hydrophobic block was investigated at the air–water and air–buffer interface. The polymer forms stable monomolecular films on both subphases. At low pH, the isotherms exhibit a plateau. Compression–expansion experiments and infrared reflection absorption spectroscopy suggest that the plateau is likely due to the formation of polymer bi- or multilayers. At high pH the films remain intact upon compression and no multilayer formation is observed. Furthermore, the mineralization of calcium phosphate beneath the monolayer was studied at different pH. The pH of the subphase and thus the polymer charge strongly affects the phase behavior of the film and the mineral formation. After 4 h of mineralization at low pH, atomic force microscopy shows smooth mineral films with a low roughness. With increasing pH the mineral films become inhomogeneous and the roughness increases. Transmission electron microscopy confirms this: at low pH a few small but uniform particles form whereas particles grown at higher pH are larger and highly agglomerated. Energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy confirm the formation of calcium phosphate. The levels of mineralization are higher in samples grown at high pH.
    CrystEngComm 03/2015; 17(36). DOI:10.1039/C4CE02274B · 4.03 Impact Factor
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    ABSTRACT: A series of long-tail alkyl ethanolamine analogs containing amide-, urea-, and thiourea moieties was synthesized and the behavior of the corresponding monolayers was assessed on the Langmuir-Pockels trough combined with grazing incidence X-ray diffraction experiments and complemented by computer simulations. All compounds form stable monolayers at the soft air/water interface. The phase behavior is dominated by strong intermolecular headgroup hydrogen bond networks. While the amide analog forms well-defined monolayer structures, the stronger hydrogen bonds in the urea analogs lead to the formation of small three-dimensional crystallites already during spreading due to concentration fluctuations. The hydrogen bonds in the thiourea case form a two-dimensional network, which ruptures temporarily during compression and is recovered in a self-healing process, while in the urea clusters the hydrogen bonds form a more planar framework with gliding planes keeping the structure intact during compression. Because the thiourea analogs are able to self-heal after rupture, such compounds could have interesting properties as tight, ordered, and self-healing monolayers.
    Langmuir 02/2015; 31(4):1296-1302. DOI:10.1021/la5039987 · 4.46 Impact Factor
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    ABSTRACT: A series of 1,3-diamido phosphocholines was synthesized, and their potential to form stable bilayers was investigated. Large and giant unilamellar vesicles produced from these new lipids form a wide variety of faceted liposomes. Factors such as cooling rates and the careful choice of the liposome preparation method influence the formation of facets. Interdigitation was hypothesized as a main factor for the stabilization of facets and effectively monitored by small-angle X-ray scattering measurements.
    Langmuir 02/2015; 31(6). DOI:10.1021/la5041745 · 4.46 Impact Factor
  • Joana S. L. Oliveira · Gerald Brezesinski ·

    International Journal of Cosmetic Science 02/2015; 37(1):157-157. · 1.38 Impact Factor
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    ABSTRACT: The aggregation behavior of various zwitterionic helper phospholipids, such as DOPE, DOPC and DPPC, in combination with two new cationic lipids, namely TH4 and OH4 (second generation of malonic acid diamides) in different molar ratios was studied with regard to their physical-chemical properties. Additionally, lipoplexes prepared from these lipid mixtures were characterized with respect to the transfection efficacy using an EGFP-assay. The lipid mixtures with the fluid cationic lipid OH4 and DOPE have shown comparable transfection efficiency with Lipofectamine 2000®. Furthermore, this report demonstrates the huge influence of the helper lipid on the transfection efficiency. Thereby, alkyl chain fluidity, lipid miscibility and charge density have an important influence on an efficient gene transfer.Practical applications: Although lipofection is a topic of gene therapy since 1989, the optimal finding of an effective lipid system with new cationic lipids is still a process of trial and error. There is much unknown understanding the process of lipoplex formation as well as the release of the genetic cargo. Aim of the presented work is to find physical-chemical parameters which are connected with an effective gene transfer.
    European Journal of Lipid Science and Technology 09/2014; 116(9):1184-1194. DOI:10.1002/ejlt.201300405 · 1.81 Impact Factor
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    Juan J. Giner-Casares · Gerald Brezesinski · Helmuth Möhwald ·
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    ABSTRACT: Physico-chemical processes at air/liquid interfaces are of paramount importance in nature. The Langmuir technique offers the possibility of forming a well-defined monolayer of amphiphilic molecules under study at the air/liquid interface,with a unique control of the area permolecule and other experimental conditions. Despite being a traditional technique in Colloid and Interface science, there is an ever growing interest in Langmuir studies. Herein, recent developing fields of research currently taking advantage of the Langmuir technique are reviewed, comprising the interfacial structure of: water, biomolecules and inorganic/organic hybrids. The good state of the Langmuir technique at present and the foreseeable increase of its usage are discussed.
    Current Opinion in Colloid & Interface Science 06/2014; 19(3):176–182. DOI:10.1016/j.cocis.2013.07.006 · 5.84 Impact Factor
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    ABSTRACT: Carbon nanostructures that feature two-dimensional extended nanosheets are important components for technological applications such as high-performance composites, lithium-ion storage, photovoltaics and nanoelectronics. Chemical functionalization would render such structures better processable and more suited for tailored applications, but typically this is precluded by the high temperatures needed to prepare the nanosheets. Here, we report direct access to functional carbon nanosheets of uniform thickness at room temperature. We used amphiphiles that contain hexayne segments as metastable carbon precursors and self-assembled these into ordered monolayers at the air/water interface. Subsequent carbonization by ultraviolet irradiation in ambient conditions resulted in the quantitative carbonization of the hexayne sublayer. Carbon nanosheets prepared in this way retained their surface functionalization and featured an sp(2)-rich amorphous carbon structure comparable to that usually obtained on annealing above 800 °C. Moreover, they exhibited a molecularly defined thickness of 1.9 nm, were mechanically self-supporting over several micrometres and had macroscopic lateral dimensions on the order of centimetres.
    Nature Chemistry 06/2014; 6(6):468-76. DOI:10.1038/nchem.1939 · 25.33 Impact Factor
  • Cristina Stefaniu · Gerald Brezesinski ·
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    ABSTRACT: Gibbs or Langmuir monolayers formed at the soft air/liquid interface are easy to handle and versatile model systems for material and life sciences. The phase state of the monolayers can be modified by lateral compression of the film while the layer structural changes are monitored by highly sensitive surface characterization techniques. The use of high brilliant synchrotron light sources for X-ray experiments is essential for the monolayer research. The present review highlights the recent achievements recorded in the monolayer field with a special emphasis on different synchrotron based X-ray characterizing methods as: grazing incidence X-ray diffraction, X-ray reflectivity and total reflection X-ray fluorescence. Some examples of single-chain surfactants, special sugar lipids, and semifluorinated compounds are given. Additionally, thin layers formed by peptides, polymers or nanoparticles are highlighted.
    Current Opinion in Colloid & Interface Science 06/2014; 19(3). DOI:10.1016/j.cocis.2014.01.004 · 5.84 Impact Factor
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  • Cristina Stefaniu · Gerald Brezesinski ·
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    ABSTRACT: The use of highly brilliant synchrotron light sources in the middle of the 1980s for X-ray diffraction has revolutionized the research of condensed monolayers. Since then, monolayers gained popularity as convenient quasi two-dimensional model systems widely used in biophysics and material science. This review focuses on structures observed in one-component phospholipid monolayers used as simplified two-dimensional models of biological membranes. In a monolayer system the phase transitions can be easily triggered at constant temperature by increasing the packing density of the lipids by compression. Simultaneously the monolayer structure changes are followed in situ by grazing incidence X-ray diffraction. Competing interactions between the different parts of the molecule are responsible for the different monolayer structures. These forces can be modified by chemical variations of the hydrophobic chain region, of the hydrophilic head group region or of the interfacial region between chains and head groups. Modifications of monolayer structures triggered by changes of the chemical structure of double-chain phospholipids are highlighted in this paper.
    Advances in Colloid and Interface Science 05/2014; 207(1). DOI:10.1016/j.cis.2014.01.005 · 7.78 Impact Factor
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    ABSTRACT: Glycosylphosphatidylinositols (GPIs) are often attributed with the ability to associate with the organized membrane microdomains. GPI fragment 1 forms a highly ordered subgel-phase structure characterized by ordering of both headgroups and alkyl chains in thin layers. While investigating the driving forces behind the formation of these ordered monolayers, we have studied polymorphism of 1 under different conditions employing surface-sensitive X-ray diffraction methods. Three distinct polymorphs of 1 (I, II, and III) were identified and characterized by grazing incidence X-ray diffraction. Polymorphs II (a condensed monolayer structure) and III (highly ordered subgel phase) coexist on an 8 M urea solution subphase allowing for a detailed thermodynamic and kinetic analysis of the processes leading to the formation of these polymorphs. They are enantiotropic and can be directly interconverted by changes in temperature or lateral surface pressure. As a consequence, polymorph III nuclei of critical size (or larger) could be formed by density fluctuations in a multicomponent system, and they could continue to exist for a period of time even under conditions that would normally not allow for the nucleation of polymorph III. The processes described here could also lead to the formation of patches of highly ordered structures in a disordered environment of a cell membrane suggesting that GPIs may play a role in the formation of such domains.
    Langmuir 04/2014; 30(18):5185–5192. DOI:10.1021/la500482s · 4.46 Impact Factor
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    C Stefaniu · I Vilotijevic · G Brezesinski · P H Seeberger · D. Varon Silva ·
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    ABSTRACT: Glycosylphosphatidylinositols (GPIs), natural complex glycolipids essential for a range of biological functions, are poorly understood with regard to their interactions and arrangements in cellular membranes. To evaluate the role of the head group in the structure formation in 2D model membranes (monolayers formed at the soft air/liquid interface), we employed the highly surface sensitive grazing incidence X-ray diffraction technique to investigate three GPI-fragments bearing the same hydrophobic part but different head groups. Condensed monolayers of simple GPI fragments are defined only by ordered alkyl chains. The monolayers of more complex fragments are additionally characterized by highly ordered head groups. Due to the strong H-bond network formed by the head groups, GPI-fragment both segregates and induces order into a model membrane phospholipid (POPC) that mimics the liquid-disordered phase of cell membranes. Here, we show that the strong van der Waals interactions between hydrophobic chains overcome the head group interactions and dominate the structure formation in mixtures of GPI-fragment with lipids that form liquid-condensed phases. This behaviour can be linked to the GPIs affinity for the lipid rafts.
    Physical Chemistry Chemical Physics 04/2014; 16(20). DOI:10.1039/c4cp00567h · 4.49 Impact Factor

Publication Stats

5k Citations
1,015.02 Total Impact Points


  • 1996-2015
    • Max Planck Institute of Colloids and Interfaces
      • Department of Interfaces
      Potsdam, Brandenburg, Germany
  • 2010
    • University of Kalyani
      • Department of Chemistry
      Kalyani, West Bengal, India
    • University of Southern Denmark
      Odense, South Denmark, Denmark
  • 1979-2010
    • Martin Luther University of Halle-Wittenberg
      • • Division of Physical Chemistry
      • • Division of Biochemistry
      Halle-on-the-Saale, Saxony-Anhalt, Germany
  • 2008
    • Utsunomiya University
      • Division of Advanced Interdisciplinary Sciences
      Totigi, Tochigi, Japan
  • 1993-2007
    • Johannes Gutenberg-Universität Mainz
      • Institute of Physical Chemistry
      Mayence, Rheinland-Pfalz, Germany
  • 1986
    • Deen Dayal Rustagi College
      Khandela, Rajasthan, India