Hybrid Polymer Blends Covalent And Supramolecular Components
Polymers: Supramolecular component can be removed and reconstituted on demand to yield soft materials with novel delivery or repair functions
By combining monomers that form a covalently linked polymer with a monomer that assembles noncovalently into a supramolecular polymer, researchers have created a novel soft material that’s distinct from the forms these monomers take on their own. The new hybrid structure, created by Samuel I. Stupp and colleagues at Northwestern University, can be partially disassembled and reassembled on demand, creating a material that could have applications in drug delivery and self-healing materials......more
Researchers Develop Completely New Kind of Polymer
Hybrid polymers could lead to new concepts in self-repairing materials, drug delivery and artificial muscles.
These functions require polymers with both rigid and soft nano-sized compartments with extremely different properties that are organized in specific ways. A completely new hybrid polymer of this type has been developed by Northwestern University researchers that might one day be used in artificial muscles or other life-like materials; for delivery of drugs, biomolecules or other chemicals; in materials with self-repair capability; and for replaceable energy sources......more
Light-harvesting materials: Soft support for energy conversion
Ronald Breslow Award For Achievement In Biomimetic Chemistry
New Geometries: Researchers Create New Shapes of Artificial Microcompartments
In nature, biological functions are often carried out in tiny protective shells known as microcompartments, structures that provide home to enzymes that convert carbon dioxide into energy in plant cells and to viruses that replicate once they enter the cell.......more
New Computer Memory Material Goes Easy on the Juice
Multitasking has a price: Your computer is sucking up a lot of electricity keeping track of work you haven't yet saved to the hard drive. Americans spend $6 billion a year on electricity to keep that data stored in a computer's memory during operation. But that figure could drop sharply, scientists report this week, thanks to a new type of material than can permanently store such data—without needing a continuous trickle of electricity to do it.......more
EVANSTON, Ill. --- A new class of organic materials developed at Northwestern University boasts a very attractive but elusive property: ferroelectricity. The crystalline materials also have a great memory, which could be very useful in computer and cellphone memory applications, including cloud computing.
A team of organic chemists discovered they could create very long crystals with desirable properties using just two small organic molecules that are extremely attracted to each other. The attraction between the two molecules causes them to self assemble into an ordered network -- order that is needed for a material to be ferroelectric.......more
EVANSTON, Ill. --- There’s nothing ordinary about the materials being designed in the Stupp Laboratory at Northwestern University. Many of the futuristic fibers, films, gels, coatings and putty-like substances have led to important advances in areas of research such as regenerative medicine and energy technologies.
These advances are part of an emerging field focused on using functional supramolecular polymers to unlock previously unknown functions of materials. A review article published in the Feb. 16 issue of the journal Science details this field and highlights some of the key developments made in the past decade......more
Aida, T.; Meijer, E. W.; Stupp, S. I. “Functional Supramolecular Polymers” Science 335(6070), (2012) 813-817.
Imagine splitting a human hair 100,000 times. Each split is a single nanometer in diameter, the size of a nanostructure.
These tiny items are being used by scientists and doctors at Northwestern University to do something big: build new blood vessels......more
Nanostructure Promotes Growth of New Blood Vessels, Mimics Natural Protein
Tissue deprived of oxygen (ischemia) is a serious health condition that can lead to damaged heart tissue following a heart attack and, in the case of peripheral arterial disease in limbs, amputation, particularly in diabetic patients.
Northwestern University researchers have developed a novel nanostructure that promotes the growth of new blood vessels and shows promise as a therapy for conditions where increased blood flow is needed to supply oxygen to tissue.
Regenerating blood vessels is important for combating the aftereffects of a heart attack or peripheral arterial disease, and for ensuring that transplanted organs receive a sufficient supply of blood. Now researchers at Northwestern University have created a nanomaterial that could help the body to grow new blood vessels.
Regenerative medicine: Noodle gels for cells
EVANSTON, Ill. --- A big question in regenerative medicine is how to most effectively deliver stem cells -- as well as other beneficial cells, proteins and large molecules -- to damaged tissues such as the spinal cord, heart and brain.
A Northwestern University team is the first to demonstrate a method that delivers cells in the same alignment as the cells found in these tissues, which could jumpstart new growth and healing. The findings are published as the cover story in the July issue of the journal Nature Materials.
Fiber Bundles Line Up
Materials science: Noodly appendages
Novel 'cell wires' to patch up heart or nerve damage
Long-range electrostatic repulsion can drive crystallization in three-dimensional networks of like-charged peptide-based filaments, according to a study from Northwestern University (Science, DOI: 10.1126/science.1182340). The unprecedented crystallization mechanism could play a previously unrecognized role in forming cytoskeletal structures—the protein “scaffolding” in cells—and lead to advances in biomedical applications. Honggang Cui, Samuel I. Stupp, and coworkers report that a synthetic molecule made from a peptide sequence grafted to an alkyl chain spontaneously forms networks of cylindrical fibers. These filaments consist of a hydrocarbon core and peptide periphery that are roughly 10 nm in diameter and estimated to be at least tens of micrometers in length. In dilute solutions of about 1 wt % or higher, repulsion between negatively charged nanofibers causes the structures to crystallize spontaneously. In less concentrated solutions, deprotonation stimulated by X-rays triggers reversible crystallization, leading to ordered fiber bundles with interfiber separations of up to 320 Å. That distance is on the order of 10 times the range of values reported for cytoskeleton filaments and DNA strands, the team says.
EVANSTON, Ill. --- Northwestern University researchers are the first to design a bioactive nanomaterial that promotes the growth of new cartilage in vivo and without the use of expensive growth factors. Minimally invasive, the therapy activates the bone marrow stem cells and produces natural cartilage. No conventional therapy can do this.
The results were published online the week of February 1st by the Proceedings of the National Academy of Sciences (PNAS).
A team of Northwestern University researchers has discovered that X-rays can trigger the formation of a new type of crystal: charged cylindrical filaments ordered like a bundle of pencils experiencing repulsive forces, which is unknown in crystals. Similar phenomena may occur naturally in biology, such as in the cytoskeleton filaments of cells, which control cell division and migration in cancer metastasis and many other processes.
New Partnership in Biomedicine and Translational Research
EVANSTON, Ill. --- Scientists from the University of Gothenburg in Sweden will deliver public talks Jan. 11 and 12 at Northwestern University to introduce an important new exchange program to the University's research community.
The two universities signed an education and research exchange agreement in Sweden last month to foster collaborative relationships in biomedicine and translational research.
Northwestern's Institute for BioNanotechnology in Medicine (IBNAM) and Gothenburg's medical school, known as the Sahlgrenska Academy, are the primary institutions in the exchange program. IBNAM's research strengths are well matched to Sahlgrenska's research interests in regenerative medicine, particularly the neural and orthopedic areas.
Collaboration Focuses on Fracture Putty for Bone Injuries
EVANSTON, Ill. --- Northwestern University is part of a multi-institution initiative to produce “fracture putty,” a biocompatible compound designed to mend serious leg fractures, such as those suffered by soldiers.
The two-year research project is funded by the Defense Advanced Research Projects Agency (DARPA), an agency of the U.S. Department of Defense.
The research team’s goal is to develop a putty-like material that could be used to regenerate bones shattered by roadside bombs or other explosive devices. This type of injury, called a non-union fracture, generally will not heal in a timely manner and can lead to amputation.
Zinc Oxide Gives Green Shine to New Photoconductors
EVANSTON, Ill. --- Photodetectors -- devices found in cell phones, digital cameras and other consumer gadgets that utilize photoconducting materials -- are a green technology in performance (converting light into electricity), but the manufacture of very powerful photodetectors needs to be improved before they can qualify for solid green status.
Northwestern University researchers have designed a high-performing photoconducting material that uses zinc oxide -- an environmentally friendly inorganic compound found in baby powder and suntan lotion -- instead of lead sulfide. (Currently, the best performing photoconductor is based on lead sulfide nanoparticles.)
Features of the new hybrid material and its synthesis are detailed in a study published by the journal Nature Materials.
Samuel Stupp and collaborators at Northwestern University have designed a material that self-assembles into tiny tubes—nanofibers—when it comes in contact with tissues. The nanofibers are studded with short strings of amino acids that signal nerve cells to grow new extensions after spinal cord injury. Within weeks of receiving the bioactive nanofiber injection, mice paralyzed from spinal cord injury showed signs of recovery. By changing the bioactive molecules on the nanofibers, it will be possible to instruct cells to behave in a desired way. This work confirms that bioactive nanofiber technology holds promise for treating a broad range of injuries and diseases. See the full story here: http://www.nibib.nih.gov/HealthEdu/eAdvances/26Nov08.
EVANSTON, Ill. --- Imagine having one polymer and one small molecule that instantly assemble into a flexible but strong sac in which you can grow human stem cells, creating a sort of miniature laboratory. And that sac, if used for cell therapy, could cloak the stem cells from the human body’s immune system and biodegrade upon arriving at its destination, releasing the stem cells to do their work.
Futuristic? Only in part. A research team from Northwestern University’s Institute for BioNanotechnology in Medicine has created such sacs and demonstrated that human stem cells will grow in them. The researchers also report that the sacs can survive for weeks in culture and that their membranes are permeable to proteins. Proteins, even large ones, can travel freely across the membrane.
Samuel Stupp has a bunch of mice that used to drag their hind legs behind them when they crawled around his Illinois lab, but they have miraculously regained at least partial use of their rear legs.
Astonishingly, their severed spinal cords have been repaired, at least partly, without surgery or drugs. All it took was a simple injection of a liquid containing tiny molecular structures developed by Stupp and his colleagues at Northwestern University. Six weeks later, the mice were able to walk again. They don't have their former agility, but their injuries should have left them paralyzed for life.
Stupp is on the cutting edge of one of the most exciting fields in medical research: regenerative medicine. If he and others in the field are on the right track, one of these days tragic diseases like Parkinson's and Alzheimer's will be a thing of the past. And the crippled will walk again as the human body repairs itself in ways that it cannot do today.
Mice induced to have heart attacks or given other wounds have quickly made a full recovery, thanks to a little help from nanotechnology. If the new results translate to humans, they could someday offer hope to millions of victims of heart attacks and other major injuries.
Even on a cellular level, wound healing takes time. The body must target a large number of molecules called growth factors to just the right area to help repair the damage. Samuel Stupp, a chemist at Northwestern University in Evanston, Illinois, and colleagues wondered whether they could speed up the process by injecting a bit of nanotechnology into the mix. The new tools are molecules called peptide amphiphiles. Once injected into the body, the amphiphiles self-assemble into long, thin nanofibers, which hang out in the wound area.
Something to be Proud Of...
IT IS all too easy to paint a grim picture of chemistry in the UK. Undergraduate enrolment in chemistry courses began to plummet in the late 1990s, bottoming out in 2003 with barely 3000 students. These dwindling numbers, coupled with the high cost of teaching the subject, have led some universities to shut down their departments. Chemists graduating from the University of Exeter, King's College London and Queen Mary, University of London, have all seen windows boarded up behind them.
Countless papers, talks and initiatives have been spawned in an effort to entice students back into the field. Working chemists should venture into classrooms, they say, armed with demonstrations of the big, loud and dangerous reactions of past schooldays. Chemistry teachers should have chemistry degrees to impart their enthusiasm to students, reckons the UK government.
But maybe there is a simpler way to turn the tide: good old-fashioned PR. One way to do this is by demonstrating how chemistry can step up to the challenges of the modern world, be it answering energy needs, addressing climate change or improving our health. So New Scientist polled a selection of leading chemists and asked them what we should be celebrating in today's chemistry, and how this research will answer the future demands of life, just as it has done for the past 200 years.
Nanostructures Help Build Blood Vessels
Nanofibres spin a sticky web for blood vessels
Biologists are embracing nanotechnology—the engineering and
manipulating of entities in the 1 to 100 nm range—and are exploiting its
potential to develop new therapeutics and diagnostics.
New fuels to wean America from
its oil dependence have become the new Holy Grail, and a professor at
Northwestern University in Evanston has made an important step in that
Nano World: Nano for stem-cell
Cutting-edge nanotechnology is beginning to help advance the equally pioneering field of stem-cell research, with devices that can precisely control stem cells and provide self-assembling biodegradable scaffolds.
Carbon Nanotubes with Amphiphilic
Peptides Dissolve in Water
S. I. Stupp and co-workers at Northwestern University, Evanston and Chicago, IL, took a “noncovalent” approach and made the nanotubes hydrophilic by wrapping them with peptide amphiphiles.
Nanofibers Seed Blood
At the ACS meeting, chemist Sam Stupp of Northwestern University in Evanston, Illinois, reported that his team has developed a novel variety of self-assembling nanofibers that strongly promote the growth of new blood vessels both in cell cultures and preliminary animal tests.
Research team develops gel to
grow blood vessels
Materials Potpourri -
Regenerative Medicine Meets Nanotechnology
Molecular line-up: using
nanoscale self-assembly for organic electronics
Future of Tissue
Biotechnology Brings Hope to Tissue
Nanomedicine's Promise Is Anything but
Color Collective: Polymer
self-assembles into light-emitting film
Grow Neurons Using Nanostructures
Bioengineers build scaffold to grow
Self-assembling scaffold for
spinal-cord repair; 'Liquid' bridge could help severed nerve cells
stem-cell gel advances spinal injury
scaffold aids rebuilding of nerves
SCIENCE & TECHNOLOGY:
The matrix, reinvented
Bone That Grows Back
Bringing a sense of order to
Polymers Line Up
Molecular template makes nanoscale helix
organic structures as templates for inorganic nano-objects
could help bones heal, Northwestern Researchers
Scientists Design Molecules That Mimic Nanostructure of
Stories of modern science... from
Molecule has potential to repair bones, scientists
Science & Technology:
The Stupp Laboratory
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