Based on the similarity of the sequences of combinatorially selected peptides that have similar binding characteristics, we developed a bioinformatics approach that provides a general and simple methodology to quantitatively categorize a large number of inorganic binding peptides. The approach also provides a way to knowledge-based design a new set of binding sequences specific to inorganic surfaces with predictable functionalities. De novo designed peptides can then be expressed using genetic tools, such as redisplay, to assess the efficacy of the design via binding affinity evaluation.

Marjorie Longo, UC Davis; Steve Boxer, Stanford University

What are PPA “foldamers” nonbiological polymers that fold model systems for self-assembling nano structures challenge for simulation: long timescale and complex dynamics  New results longer chains considerably are more complex: multiple traps and remarkable complexity new methods used to predicted long timescale behavior: Markovian model and Folding@Home grid computing

The nanoscale engineering is one of the most dynamic domains at the interface between electronics, physics, biology and medicine. As there is no regulation yet, concern about future health problems is raising. We have investigated the cytotoxicity of Citrate/Gold nanoparticles at different concentrations and times. Major effects on cells appeared as a result of the internalization of nanoparticles, such as disruption of the actin cytoskeleton, loss of spreading and growth, as well as protein synthesis, and reduction of phagocytosis of bacteria.

The vortex state of a magnetic nanoring has special attributes of no magnetic poles nor stray fields. The circulatory magnetization can have two chiralities:, left-handed or right-handed, for storing "0" and "1", as shown in Fig. 1. Fig. 1: Two chiralities of a magnetic nanorings for storing "1" and "0".

Periodically, the MRSEC posts scientific nuggets, i.e. brief one or two page descriptions of important scientific or technological discoveries and innovative new outreach initiatives which have resulted from NSF or other support. Feel free to explore the ones that we have provided here. The nuggets are in .pdf format.

Center researchers have found liquid crystal phases in systems of circular or spherical particles, a surprise since liquid crystals usually appear in molecules shaped like sticks or plates. The trick is to give hard particles (purple) a soft repulsive "halo" (green) The resulting phase behavior is extraordinarily rich, including "lyotropic" liquid crystal phases and a variety of complex modulated crystal phases.

Graphitic Carbon Produced at Very Low Temperatures during the Synthesis of Iron Oxide NanoparticlesGraphitic carbon - structural forms of the element that are constructed exclusively from carbon atoms having trigonal planar coordination - is ordinarily produced under drastic physical and conditions, typically at temperatures in excess of 500ï‚° C. Columbia MRSEC scientists have uncovered a process by which this form of matter can assemble at temperatures as low as 110ï‚° C. During their development of a low-temperature synthesis of nanocrystals of iron oxides, Drs.

A femtosecond laser is used to perform "nano" surgery on a living cell. The actin filaments in the cell have been fluorescently labeled using green fluorescent protein (GFP). When a single filament is cut, it retracts, much like a violin string that has broken. This demonstrates that the actin filaments in the cell are under tension, and hence are being "pulled" apart.

On October 20, 2006, the UMN MRSEC hosted 450 participants from the Minnesota FIRST Lego League “Nanoquest” competition. FIRST Lego League is an organization, which “introduces children around the world to the fun and experience of solving real world problems by applying math, science, and technology”*.