PROJECT MAP FOR TEAM RUSSOPolypeptides Hydrophobins

Polyelectrolytes

Stackers

DIM (Disease-Inspired Material)Physical Insight

Synthetic/Preparative

Methods Development

Have Fun

Discover Solve

Build

Indulge Curiosity

Serve

Create

Wonder Imagine

Publish & Graduate

Words

Policies

Pyramid Scheme

Janus

Muscle

Saturn

Jamming

Propellerhead

Magnaphase

Star RodsAerocrystals

Polycolloid

LabJack

Onion

Rigatoni

Pouch

SAPRODSurfactant-assisted Processing of Rods

LBL via Click

SANCC=Self-Annealing ColCryst

SADLC = Self-Assembly Driven LC

CCC=Conc-Conf-Coupling

ProbeSAD-ColCryst =Self-Assembly Driven Col.Crys.

Responsive

PEGLChar/DvsC/CUBubbleComposite

Arborols*Dilutability*Inhibitor micelles*Inhibition*SADLCǂ

*Tunnels

Porphyrins*Dilutability*Micelle typeStackers*Inhibition*Tunnels*Applications: photodynamic cancer therapy (Vicente) or light harvesting

Conifer MACE

Measure nothing first, measure something unimportant next.

More, bolder, faster. --Frank Karasz

Watch your thoughts, they become your words.Watch your words, they become your actions.Watch your actions, they become your habits. –Freeman Hrabowski

Do the right thing—it will gratify some people and astonish the rest. –Mark Twain

10 20 30 40 502.90

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MADLS*Everyday use*Ergonomics*Research-grade

Holo-FPR

SAXS*Summed runs*Flow cell*Svergun softwareOPTICAL MICROSCOPY

*LED FPR*Particle tracking*MSFCS*Video FPR

TEM*FF/TEM*Cryo

*Making better molecules.*Mixed polyelectrolytes*Holo-FPR/Shortscale PE

Legend to Motivating Themes

MagnaChain-LCExpt/Sim

Help teammates.Master’s, then Ph.D.Seek internal review.Gutsy mistakes can usually be fixed, fretfully doing nothing cannot. Only the inquisitive need join.

Cowlick

Bubbles =hydrophobin-stabilized cylindrical bubbles*pH, salt, temp, gases, pressure*persistence length by digital microscopy*size distribution by Nanosight & SLS/DLS*SAXS, cryo-TEM and FFTEM for wall thickness*Particles that adhere*stabilization*liquid crystallinity/directed transport

Blob = hydrophobin-stabilized oil blobs

*oil spill cleanup*solvent entrapment

*monomer entrapment/polymerization*mesogen entrapment

*lyotropic LC entrapment/optical devices*magnet entrapment

*dried to directed/rough surfaces

*ǂSelf-assembly driven liquid crystals

CollaboratorsExisting: Vicente, Zhang, Negulescu, Daly, Nesterov, F. Hung (ChE), Z. Liu (RNR), Q. Wu (RNR)

Janus fuzzballsJanus was the Roman god of gates, doors, doorways, beginnings, endings and time. He had two faces, sometimes different, looking in both directions. The idea here is to make a submicron particle which has one side coated with polypeptide and the other side coated with something else, or uncoated at all.

We think these particles will be good for applications like controlled surface chemistry (hydrophobic or hydrophilic, switchable) or capture/delivery of chiral molecules. For example, the polypeptide face could be oriented to capture a chiral molecule from solution and then spun around to deliver it into a different phase.

The closest we have come to making a Janus fuzzball was the work of Erick Soto-Cantu, who managed to get one side of a silica particle coated with gold and the other coated with silica. Placement of an azide coupling agent on the silica side followed by click reaction with an alkyne-initiated polypeptide should produce the desired particle.

Currently investigated by Cornelia Rosu of Romania

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Janus car!

MagnachainSome fuzzballs are equipped with a superparamagnetic* nougat. This enables them to exhibit magnetism but only in the presence of an applied field. So….when a magnetic field is applied, each particle develops a “north” and a “south” pole. These are attracted to each other, resulting in chains.

Applications of this include viscosity modification (magnetorheological effect, found in shock absorbers in expensive luxury and sports cars) and optical polishing (long story).

Our interest is trying to link the fuzzballs together once they are aligned. Then, taking advantage of the ability of polypeptides to expand and contract in response to temperature and pressure (and maybe one day light) we hope to expand and contract the chain, like muscle.

Currently investigated by Cornelia Rosu of Romania

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Jamming Currently studied by Melissa Collins of Louisiana

This is one of our most intricate and subtle projects. When particles bearing surface groups that can be extended rods but which can also be floppy random coils are jammed together by magnetic attraction, will the polymers choose the rodlike conformation in order to form “local liquid crystals” at the interfaces? If so, then we have coupled a magnetic field to a molecular (and optical) transformation.

The very notion of a local liquid crystal was motivated by the observation of former student Jianhong Qiu that particles jammed together in good solvents for the shell polymers remained stuck to each other, while selecting a poor solvent for the shell resulted only in transient adhesion of the chained assembly of particles.

The hypothesis that a local liquid crystal is involved is tested with small-and wide-angle X-ray scattering. The overall stability of the polypeptide-coated particles is being developed, too—for example, by dynamic light scattering measurements at modest concentrations.

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Probe Diffusion/Microrheology Currently studied by Melissa Collins of Louisiana

Did you ever wonder what it would be like to ride around on a molecule? How do particles see polymers in solution. We don’t know, but it’s really important because all sorts of particles from paints to proteins are dispersed with polymers. Suppose they are carrying drugs, trying to deliver them to the inside of a cell. How fast will they be able to go? Or, suppose you are trying to measure the viscosity of fluid inside a living cell, or the viscosity of supercritical CO2 (considered a “green” solvent compared to some organic liqiuds, despite release of CO2 to the atmosphere after evaporation). Well, you can just measure the speed of diffusion of some probe particle through the solution and back out the viscosity. Current research focuses on using polypeptide-coated spheres, whose surface can be altered. For example, can we have a particle diffuse around inside a living system, then undergo helix-to-coil transition to “latch onto” materials in the cell? We use dynamic light scattering and other methods to measure the probe speed.

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StackersStackers are molecules that lay on top of each other to make a very long fiber. We study two basic kinds: porphyrins (with help from Prof. Vicente) and arborols. Both have a molecular weight of about 1000 g/mol—pretty small by our standards. The porphyrins are macrocycles, while the arborols assume the shape of a dumb-bell.

The porphyrins can capture light. One of their main uses is photodynamic therapy—shine a light on them to release a drug. The arborols make great model systems for amyloid fibrils; we also hope to use them to force a solution containing rodlike polymers to switch into a liquid crystalline phase. This would let polymer liquid crystals perform certain sensing and possibly display applications.

Multiple methods are used to understand Stackers. At right, results from small-angle X-ray scattering and cryo-transmission electron microscopy.

Currently studied by Javoris Hollingsworth of Georgia

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and ChE undergrad Mohammed Abu Laban

The protein Cerato ulmin is one of nature’s most powerful surfactants. Produced by fungi, cerato ulmin and related proteins have been in the oceans for eons.

Cerato ulmin rod-shaped bubbles.

Elm afflicted with Dutch elm disease

Tree: http://www.iwight.com/living_here/planning/images/DutchElmDisease01.jpg http://cims.hispanictips.com/uploads/2008/03/sickle-cell-picture.jpg

Oil-filled bubble can be moved using optical tweezers.

http://www.invasive.org/images/768x512/0355036.jpg

Model of a comparable protein; note green hydrophobic and gray hydrophilic

regimes.

Mostly known for its toxicity to elm trees, yet safe to animals, cerato ulmin encapsulates air and oil in unusual cylindrical structures having remarkable stability. Very small quantities are required.

Hydrophobins

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