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Helmut H. Strey

T: 631.632.1957
F: 631.632.8577
E: Helmut.Strey@stonybrook.edu

Bioengineering G13
Stony Brook, NY 11794-5281

Helmut H. Strey

Research Focus

Nanostructured Materials for Applications in Bioseparation, Drug Delivery and Biosensors. Nature’s ability to assemble simple molecular building blocks into highly ordered materials, such as those found in cell membranes, cell nuclei, cytoskeleton, cartilage, or bone presents many fascinating and unanswered questions. We are interested in how to tune the interactions of water-soluble building blocks so as to induce their assembly into useful microstructures much needed for the next generation of controlled drug delivery, biosensors and DNA sequencing applications. In particular, we are working on:

  1. Long-range ordered polyelectrolyte-surfactant microemulsions that are used as templates for solid nanoporous materials using polymerization and/or cross-linking strategies. Such materials, because of their well-ordered porous structure, will allow more efficient molecular separation and drug delivery.
  2. We are developing biosensors that are based on biopolymer chiral liquid crystals and quantum dot colloidal crystals. In both cases the softness of the systems allows the induction of a strong optical response to external stimuli. Such sensors should be able to quantitatively detect and measure analyte concentrations at hormonal levels.
  3. We are developing methods to perform biomolecular separation on a chip. Using e-beam lithography we are creating cavity arrays that will allow to separate biomolecules over several orders of magnitude in molecular weight. We study diffusion and intramolecular dynamics employing single-molecule fluorescence.
  4. Education

    • 1990 Diploma in physics, Technical University Munich, thesis advisor: Prof. E. Sackmann
    • 1993 Ph.D. in physics (magna cum laude), Technical University Munich, thesis advisor: Prof. E. Sackmann

    Research and Professional Experience

    • 1990-1993 Research Assistant, Biophysics, Research Group, Technical University, Munich
    • 1994-1998 Visiting Fellow, National Institutes of Health, Bethesda, MD
    • 1998-2004 Assistant Professor, Department of Polymer Science and Engineering, Univ. of Massachusetts, Amherst
    • 2002-2003 Visiting Professor at New York University
    • 2004-2008 Assistant Professor, Department of Biomedical Engineering, Stony Brook University
    • 2008-present Associate Professor, Department of Biomedical Engineering, Stony Brook University


    • Visiting Fellow Award (5 years), National Institutes of Health, Bethesda, MD.
    • Research Fellowship (2 years), Deutsche Forschungsgemeinschaft, Germany.
    • Schlossmann Award 1995, Max-Planck Society, Germany.
    • GenCorp Signature University Award 1999.
    • NSF CAREER Award (CMP) 2000-4
    • Dillon medal 2003 of the American Physical Society

    Professional Activities

    • Society Membership:
      • 1994 to present German Biophysical Society
      • 1994 to present Biophysical Society
      • 1995 to present Material Research Society
      • 1997 to present American Physical Society
      • 2003 to present American Chemical Society
    • Referee:
      • Annals of Biomedical Engineering
      • Physical Review Letters and PRE
      • Macromolecules
      • Journal de Physique
      • Biophysical Journal
      • Langmuir
      • Proceedings of the National Academy of Science
    • Conference & Other Activities:
      • Organized workshop “Structure of Biopolymer Solutions: Semiflexibility with a Twist” during the Biophysical Society Meeting ‘98.
      • Complex Fluids symposium co-organizer at the Fall Meeting of the Material Research Society ’99.
      • Discussion leader for the 1999 Gordon Conference on Condensed Matter Physics.
      • Coordinator of IRG 3 ( Aqueous Polymer Assembly ) of the UMass NSF Material Research Science and Engineering Center
      • Faculty of Chemistry-Biology Interface Training Program at UMass
      • Co-organizer of the International Symposium on Polyelectrolytes 2004 at UMass Amherst.
      • Member of the organizing committee for the 2007 North East Biomedical Engineering Society Meeting
      • Organized workshop “Nanofluidics” at the joint NSLS/CfN user meeting 2008 at Brookhaven National Labs


    • Peterson M., Strey H., Sackmann E., Theoretical and Phase Contrast Microscopic Eigenmode Analysis of Erythrocyte Flicker: Amplitudes, J. Phys II France 2(1992)1273-1285.
    • Zilker A., Strey H., Sackmann E., Erythrocyte Membranes: Tethered Shells with Fluid-Like Deformation Regime, The Structure and Conformation of Amphiphilic Membranes, Springer Proc. in Physics 66(1992)113-137.
    • Käs J., Strey H., Bärmann M., Sackmann E., Direct Measurement of the Wave-Vector-Dependent Bending Stiffness of Freely Flickering Actin Filaments, Europhys. Lett., 21(1993)865-870.
    • Strey H., Bestimmung elastischer Eigenschaften von Zellmembranen und Zytoskelett mittels Flickerspektroskopie, Thesis 1993, TU-München.
    • Käs J., Strey H., Sackmann E., Direct imaging of reptation for semiflexible actin filaments, Nature 368(1994)226-229.
    • Sackmann E., Käs J., Strey H., The Observation of Polymer Reptation, Adv. Mater. 6(1994)507-509.
    • Rädler J., Feder T.J., Strey H.H., Sackmann E., Fluctuation analysis of tension-controlled undulation forces between giant vesicles and solid substrates, Phys. Rev. E. 51(1995)4526-4536.
    • Strey H.H., Peterson M., Sackmann E., Measurement of Erythrocyte Membrane Elasticity by Flicker Eigenmode Decomposition, Biophysical J. 69(1995)478-488.
    • Podgornik R., Strey H.H., Rau D.C., Parsegian V.A., Watching molecules crowd: DNA double helices under osmotic stress, Biophys. Chem. 57(1995)111-121
    • Rädler J., Strey H., Sackmann E., On the Phenomenology and Kinetics of Lipid Bilayer Spreading on Hydrophilic Surfaces, Langmuir 11(1995)4539-4548.
    • Käs J., Strey H., Tang J.X., Finger D., Ezzell R., Sackmann E., Janmey P.A., F-actin, a model polymer for semiflexible chains in dilute, semidilute, and liquid crystalline solutions, Biophys. J. 70(1996)609-625.
    • Podgornik R., Strey H.H., Gawrisch K., Rau D.C., Rupprecht A., Parsegian V.A., Bond Orientational Order, molecular motion and free energy of high-density DNA mesophases, PNAS 93(1996)4261-4266.
    • Lasic D.D., Strey H.H., Podgornik R., Stuart M.C.A., Frederik P.M., DNA - Cationic Liposome Complexes: Structure and Structure-Activity Relationships, J. Am. Chem. Soc. 119(1997)832-833.
    • Strey H.H., Parsegian V.A., Podgornik R., Equation of State for DNA liquid crystals: fluctuation enhanced electrostatic double layer repulsion, Phys. Rev. Lett. 78(1997)895.
    • Templeton N.S., Lasic D.D., Frederik P.M., Roberts D.D., Strey H.H., Pavlakis G.N., Novel DNA:Liposome Complexes for Increased Systemic Delivery and Gene Expression, Nature Biotechnology 15(1997)647-652.
    • König B., Strey H.H., Gawrisch K., Membrane Lateral Compressibility Measured by NMR and X-ray Diffraction - Effect of Acyl Chain Polyunsaturation, Biophys. J. 73(1997)1954-1966.
    • Strey H.H., Podgornik R., Rau D.C., Parsegian V.A., DNA-DNA interactions, Curr. Opin. Struct. Biol. 8(1998)309-313. Podgornik R., Strey H.H., Parsegian V.A., Colloidal DNA, Curr. Opin. Colloid & Interface Science 3(1998)534-539.
    • Strey H.H., Parsegian, V.A., Podgornik R., Equation of State for Lyotropic Polymer Liquid Crystals: Theory and Experiment, Phys. Rev. E 59(1999)999-1008.
    • Strey H.H., Wang J., Podgornik R., Rupprecht A., Yu L., Parsegian V.A., Sirota E., Refusing to Twist: Demonstration of a Line Hexatic Phase in DNA Liquid Crystals, PRL 84(2000)3105-3108.
    • Podgornik R., Strey H.H., Parsegian V.A., Physical forces molding DNA-lipid complexes, in “Gene Therapy: Therapeutic Mechanisms and Strategies”, Eds. Templeton N., Lasic D., Marcel Dekker, New York 2000, p.209-239.
    • Leonard M., Hong H.,Easwar N., Strey H.H., Soft matter under osmotic stress, Polymer 42(2001)5823-5827.
    • Ausili P., Strey H.H., Mariani P., X-ray diffraction analysis of four-stranded helices of guanosine 5’-monophosphate: structural properties and lyotropic phase behavior, submitted to Biophysical J.
    • Nykypanchuk D, Strey H.H, Hoagland D.A., Brownian Motion of DNA Confined in a Two-dimensional array, Science 297(2002)987-990.
    • C. Stanley, Strey H.H., Poly (ethylene glycol) solution osmotic pressure measured by analytical ultracentrifugation, Macromolecules 36(2003)6888 –6893.
    • Leonard M., Strey H.H., Phase Diagrams of Stoichiometric Polyelectrolyte-Surfactant Complexes, Macromolecules 36(2003)9549-9558
    • S. Sohn, Strey H.H., Gido S.P., Phase behavior and hydration of silk fibroin, Biomacromolecules 5(2004)751-757.
    • Nykypanchuk D., Strey H.H., Hoagland D.A., Single molecule study of polymer partitioning in model pore geometries, Macromolecules 38(2005)145-150
    • Chaiyasit, W.; Stanley, C.B.; Strey, H.H.; McClements, D.J.; Decker, E.A. Impact of surface active compounds on iron catalyzed oxidation of methyl linolenate in AOT-water-hexadecane Systems. Food Biophysics 2007, 2:57-66
    • C. Stanley, H.H. Strey, Electrostatically Driven Self-Assembly of Hybrid Elastin-DNA Liquid Crystals, Soft Matter 2008, 4:241-244
    • C. Stanley, H.H. Strey, Osmotically induced Helix-Coil Transition in Poly(glutamic acid), Biophysical Journal 2008, 94:4427-4434
    • Nause R., Hoagland D.A., H.H. Strey, Structural Evolution of complexes of polystyrene sulfonate and cetyltrimethylammonium chloride, Macromolecules 2008, 41:4012-4019
    • Mujica-Parodi L., Strey H.H., Frederick B., Savoy R., Cox D., Botanov Y., Tolkunov D., Rubin D., Weber J., Chemosensory Cues to Conspecific Emotional Stress Activate the Amygdala in Humans, PLoS One, 2009, 4(7):e6415
    • Nykypanchuk D., Hoagland D.A., H.H. Strey, Diffusion of Circular DNA in 2-Dimensional Cavity Arrays, ChemPhysChem 2009, 10(16)2847-2851.
    • Leonard M., Strey H.H., Measurement of Phase Transition Free Energies in Polyelectrolyte-Surfactant Complexes, Macromolecules 2010, 43,4379-4383.
    • Stanic V., M. Mancuso, W. Wong, E. DiMasi and H.H. Strey, Phase diagrams of Electrostatically Self-Assembled Amphiplexes, Macromolecules 2011, 44, 7423-7429.
    • Radulescu A.R., D. Rubin, H.H. Strey, and L.R. Mujica-Parodi, Power Spectrum Scale Invariance Identifies Prefrontal Dysregulation in Paranoid Schizophrenia, Human Brain Mapping, 2012, 33, 1582-1593.

    Invited Talks

    • Jun. 95: Supercoiled Plasmid DNA as a Possible Chiral and Rodlike Model Molecule Forming Cholesteric Liquid Crystals, Schlossmann Seminar of the Max-Planck Society, Mainz.
    • Aug. 95: DNA Mesophases: An Osmotic Stress Study, Gordon Conference on Complex Fluids, NH.
    • Feb. 96: Liquid Crystalline Packing of DNA Molecules: An Osmotic Stress Study, Condensed Matter Seminar, University of Pennsylvania, PA.
    • Feb. 96: Liquid Crystalline Packing of DNA Molecules: An Osmotic Stress Study, 290K Lecture, University of California Berkeley, CA.
    • Oct. 96: Chirality, Structure and Free Energy of DNA liquid crystals, Université Paris Sud, Orsay, France.
    • Mar. 97: Chirality, Structure and Free Energy of DNA liquid crystals, APS March meeting 1997.
    • Apr. 97: Chirality, Structure and Free Energy of Biopolymer liquid crystals, Condensed Matter Seminar at Princeton University, NJ.
    • Jun. 97: Biopolymer Liquid Crystals: A new story with a twist, Liquid Crystals Gordon Conference, NH.
    • Dec. 97: Chirality, Structure and Free Energy of Biopolymer liquid crystals, MRS Fall Meeting, Boston, MA.
    • Oct. 98: DNA condensation and applications in gene therapy, Genetic Therapy Inc., Gaithersburg, MD.
    • Feb. 99: DNA condensation and applications in gene therapy, Brookhaven National Lab, Upton, NY.
    • Oct. 99: Soft matter under osmotic stress, James Franck Institute Colloquium, Univ. of Chicago, IL.
    • Apr. 2000: Soft matter under osmotic stress, Columbia University, NY
    • Jun. 2000: Soft matter under osmotic stress, ANL theory institute on “Structure, dynamics and charge transport in polymeric materials”, IL.
    • Aug. 2000: Biopolymers, Neutron and X-ray scattering school, Argonne National Labs, Argonne, IL.
    • Aug 2001: Anomalous x-ray scattering on Co3+ condensed DNA fibers, workshop on “Polymer theory vs. experiment”, Telluride, CO
    • Feb. 2002: From micro to nano: polymer transport in long-range ordered porous materials, Gordon Conference on "Colloidal, Macromolecular & Polyelectrolyte Solutions", Ventura, CA
    • Feb. 2002:, Polymer Colloquium, MIT, Cambridge, MA.
    • April 2002: Anomalous X-ray scattering on DNA liquid crystals, NSLS workshop: Frontiers for Synchrotron Research on Soft Matter and Biomaterials, NY
    • Nov. 2002: DNA Diffusion Observed in a Two-Dimensional Hexagonal Array, Cornell University, Ithaca, NY
    • April 2003: DNA Diffusion Observed in a Two-Dimensional Hexagonal Array, Solid State Science Committee, National Academy of Sciences, Washington D.C
    • Sep. 2003: Polyelectrolyte-surfactant microemulsions, ACS meeting, New York, NY
    • March 2004: Transport in nanoporous materials. Gentner Symposium on the Physics of Biomaterials and Soft Matter, Dead Sea, Israel.
    • October 2005: DNA separation and genotyping on-a-chip, Oesper Symposium in honor of Dr. Adrian Parsegian
    • May 2006: Electrostatically self-assembled nanostructured biomaterials, CFN/NSLS user meeting, Brookhaven National Laboratories, NY
    • Feb 2007: Biopolymer separation in cavity arrays, 58th Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy, Chicago, IL
    • July 2008: Microfluidics for applications in genomics, 13th International Congress of Biorheology, Penn State University, PA
    • September 2009: Single cell mRNA extraction and expression analysis using droplet microfluidics, EMBO conference: Physics of Cells, Primosten, Croatia
    • July 2011: Droplet microfluidics technologies for single cell gene expression analysis, Gordon Conference on Microfluidics, Physics & Chemistry
    • August 2012: Thermodynamics of Polyelectrolyte – surfactant binding, Conversations in Biological Physics, Amherst, MA