Spring 2013 Magazine

The Brain

Stories From the Intersection

Energy and environment • Health and wellness • Materials • Systems • Creating leaders


Download a PDF version of this story

Health and Wellness

New Method Improves Delivery of Gene Therapy

Erik Luijten Targeted gene therapy could be a promising step toward the treatment of numerous genetic disorders, but its complexity has made execution a challenge. To be effective, a “carrier” particle must transport snippets of healthy DNA through the patient’s bloodstream and deposit them inside cell nuclei in a specific part of the body. But too often the DNA arrives at its target damaged—or it doesn’t arrive at all.

DNA molecules (light green) are packaged into nanoparticles by using a polymer with two different segments. One segment (teal) carries a positive charge that binds it to the DNA, and the other (brown) forms a protective coating on the particle surface.A new method for transporting DNA molecules to controlled locations in the body has been developed by researchers at Northwestern and Johns Hopkins University. It takes advantage of a significant finding: that different parts of the body absorb different nanoparticles depending on the nanoparticles’ shapes.

Johns Hopkins researchers found a way to regulate the shape of DNA-containing nanoparticles, and Erik Luijten, associate professor of materials science and engineering and of applied mathematics at Northwestern, led the computational analysis of the findings to determine why the nanoparticles formed into different shapes.

Simulations were performed on Quest, Northwestern’s highperformance computing system. Some of the computations were so complex that they required 96 computer processors working simultaneously for one month.

Creating Leaders

Companies Recognized for Innovations

BriteSeed team members (left to right): Paul Fehrenbacher, Mayank Vijayvergia, Jonathan Gunn, and Muneeb BokhariThree firms with roots at McCormick were honored as “Up-and-Comers” at the 2012 Chicago Innovation Awards held in October 2012. The annual awards recognize the most innovative new products or services brought to market or to public service in the Chicago region. Nine winners were selected from 180 candidates.

The Northwestern Global Health Foundation was recognized for its HIV test for infants in developing countries. (For more, see "Quick-Results HIV Test for Babies to Debut in Mozambique".) The independent nonprofit biotech company develops and distributes medical diagnostics for global health applications, based on technologies developed at McCormick.

NuMat Technologies was recognized for software that makes gas storage more effcient by analyzing and quickly suggesting ideal metal-organic-framework structures for custom storage applications. MOFs have the potential to transform products such as natural gas vehicles. The NuMat team represents four Northwestern schools: McCormick, the Kellogg School of Management, the School of Law, and Weinberg.

BriteSeed was recognized for SafeSnips, technology that can be integrated into surgical tools to detect blood vessels during surgery and prevent unintended bleeding. Students in Northwestern’s NUvention: Medical Innovation course founded the medical device startup. Team members are Paul Fehrenbacher, Mayank Vijayvergia, Jonathan Gunn, and Muneeb Bokhari.

Energy and Environment

New Process Blocks Unwanted Reactants in Oxide Catalysis

Oxide catalysts, typically formulated as powders, play an integral role in many chemical transformations, including cleaning wastewater, curbing tailpipe emissions, and synthesizing most consumer products.

A straightforward and generalizable process for making reactant-selective oxide catalystsGreener, more effcient chemical processes would benefit greatly if solid oxide catalysts were choosier about their reactants. Researchers from Northwestern and Argonne National Laboratory have developed a straightforward and generalizable process for making reactant-selective oxide catalysts by encapsulating the particles in a sieve-like film that blocks unwanted reactants.

The process, developed at Northwestern by Justin Notestein, assistant professor of chemical and biological engineering, could find applications in energy, particularly the conversion of biomass into sugars and then fuels and other useful chemicals.

In testing their method the researchers focused on photocatalytic oxidations, such as the notoriously unselective conversion of benzyl alcohol into benzaldehydes. They coated a core particle of titanium dioxide, a harmless white pigment, with a nanometerthick film of aluminum oxide pitted with tiny “nanocavities” that allowed only the smaller reactants to slip through and react with the titanium oxide.


Tool Could Speed Web Performance by 40 Percent

Namehelp, a tool to improve the performance of public domain name systemsA research team led by Fabián Bustamante, associate professor of electrical engineering and computer science, has developed namehelp, a tool to improve the performance of public domain name systems.

The team’s large-scale study involving more than 10,000 hosts across nearly 100 countries found a relationship between slow web performance and a trend toward public DNSs.DNSs translate domain and host names into Internet protocol addresses; computers perform DNS lookups before establishing website connections. Users presumably are directed to the geographically closest version of the website replicas on thousands of worldwide servers. But Bustamante’s team found that public DNSs may send users to replicas three times farther away than necessary, slowing web surfing.

The team’s large-scale study involving more than 10,000 hosts across nearly 100 countries found a relationship between slow web performance and a trend toward public DNSs. Although public DNSs offer better security, privacy, and resolution time than the “private” services offered by Internet service providers, Bustamante’s group found that the hidden interaction of public DNSs with content delivery networks can hurt web performance.

To solve the problem, the researchers developed namehelp, a tool that may speed web performance by 40 percent. The tool, which determines a user’s optimal DNS configuration, can be downloaded from the Aqualab research group website.


Model Predicts Movement of Charged Particles in Complex Media

Monica Olvera de la CruzThanks to the laws of elementary electrostatics, the force that two charged particles in a vacuum exert on one another can be easily calculated and their resulting movements predicted. But real biological and material systems, such as plant cells and blood cells, are less predictable because they are made up of several media and may be oddly shaped.

Monica Olvera de la Cruz, Lawyer Taylor Professor of Materials Science and Engineering and of chemistry, and partners from Arizona State University have developed a model that can predict the reactions of any charged particle.

Molecular simulations in heterogeneous mediaCreating molecular simulations in heterogeneous media requires measuring the effects of a medium’s dielectric response and the charged particles on one another. In previous simulation attempts the two effects were calculated separately using a differential equation. By dispensing with the equation and reframing the challenge as an energy-minimizing problem, the researchers were able to calculate the position of the charged particles and the medium’s response in the same simulation time step. The discovery could have applications in biology, medicine, and synthetic materials research.