'Custom' nanoparticles, cancer diagnosis and treatment

'Custom' nanoparticles could improve cancer diagnosis and treatment

ATLANTA, March 26 — Researchers have developed "custom" nanoparticles that show promise of providing a more targeted and effective delivery of anticancer drugs than conventional medications or any of the earlier attempts to fight cancer with nanoparticles. Designed at the molecular level to attack specific types of cancer without affecting healthy cells, the nanoparticles also have the potential to reduce side effects associated with chemotherapy, the researchers say. Their study was described today at the 231st national meeting of the American Chemical Society, the world’s largest scientific society.

The particles, considered the next generation of cancer therapeutics, are the most uniform, shape-specific drug delivery particles developed to date, according to researchers at the University of North Carolina (UNC) in Chapel Hill. Other potential benefits of the tiny uniform particles include enhanced imaging of cancer cells for improved diagnosis and use as delivery vehicles for gene therapy agents, they say.

To date, the UNC researchers have produced a variety of custom nanoparticles from biocompatible organic materials using techniques they adapted from processes used by the electronics industry to make transistors. In cell studies, they have shown that the uniform nanoparticles can attach to specific cell targets, release important chemotherapy drugs inside cells, and hold MRI contrast agents. Animal studies began recently and human studies are anticipated, the researchers say.

"I think this will transform the way one detects and treats disease," says study leader Joseph DeSimone, Ph.D., a chemistry professor at UNC and director of the school’s Institute for Advanced Materials, Nanoscience and Technology. He has co-founded a company, Liquidia Technologies, to develop and produce the nanoparticles.

Researchers have been experimenting with nanoparticles as drug delivery vehicles for years but have had only limited success in cell and animal studies, DeSimone says. Each carrier has drawbacks with regard to stability in the bloodstream or ability to be directed toward a specific cancer site. In addition, there has been no general method available that allows precise control of the particle’s size, shape and composition, which are considered key features for the success of targeted drug delivery, he says.

Now, DeSimone and his associates at UNC have developed a new fabrication technique that allows, for the first time, unprecedented control over the structure and function of drug delivery nanoparticles. Called PRINT (Particle Replication In Non-wetting Templates), the technique is similar to injection molding and uses principles borrowed from the electronics industry for transistor fabrication, they say. The technique was first detailed last June in the online version of the Journal of the American Chemical Society.

The manufacturing process starts with a silicon wafer that is etched with the shape and size of the desired nanoparticle, resulting in a template. Next, nonstick liquid fluoropolymers are poured into the template and cured to form a fixed mold. The finished mold is then injected with organic materials that can contain imaging agents, anticancer drugs, DNA (for gene therapy) and other materials, depending on the intended function, DeSimone says. The new manufacturing technique uses gentler processing methods that are less likely to harm important organic components than traditional nanoparticle manufacturing techniques, he adds.

The resulting nanoparticles can be as small as 20 nanometers, or thousands of times smaller than the width of a single human hair. The shapes of the particles can also be made to mimic the shapes of objects found in nature like red blood cells or virus particles, DeSimone says. ###

Funding for the current study is provided by the National Science Foundation and the National Institutes of Health.

The American Chemical Society — the world’s largest scientific society — is a nonprofit organization chartered by the U.S. Congress and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.

The paper on this research, COLL 9, will be presented at 11:35 a.m., Sunday, March 26, OMNI at CNN Center, International Ballroom E, during the symposium "Biomolecular and Polymeric Nanostructures and Interfaces: Fabrication, Characterization, Function, and Applications."

Joseph M DeSimone, Ph.D., is the William R. Kenan, Jr., Distinguished Professor of Chemistry and Chemical Engineering at the University of North Carolina, Chapel Hill.

Public release date: 26-Mar-2006, Contact: Michael Bernstein m_bernstein@acs.org 202-872-4400 American Chemical Society

Technorati Tags: Nano or Nanotechnology and nanoparticles or Nanotech and Science or nanochemistry and American Chemical Society or gene therapy and nanoscale or Biological and Particle Replication In Non-wetting Templates or chemotherapy and anticancer or DNA

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Green nanochemistry, American Chemical Society symposium

Green nanochemistry featured at American Chemical Society symposium, March 26-29 (Public release date: 26-Mar-2006)

PLEASE NOTE: The papers in this tipsheet are presented on different days and times but are all embargoed for the date/time shown above.

ATLANTA, March 26 — Using principles of green chemistry, scientists are designing materials and processes that provide the maximum benefits of nanotechnology while minimizing potential hazards. Green nanochemistry will be featured during a four-day symposium, "Nanotechnology and the Environment," March 26-29, at the 231st national meeting of the American Chemical Society, the world’s largest scientific society. The symposium also will address applications of nanotechnology in medicine, electronics and energy. All presentations in this symposium take place at the Georgia World Congress Center. Selected topics are described below.

Sunday, March 26

EPA scientist addresses “state of the science” of environmental nanotechnology —Barbara Karn, Ph.D., an environmental scientist with the U.S. Environmental Protection Agency’s National Center for Environmental Research, will provide an overview of the current “state of the science” of environmental nanotechnology, including greener processes and new applications of green nanotechnology. She currently is on detail as a Visiting Scientist to The Project on Emerging Nanotechnologies at the Woodrow Wilson International Center for Scholars in Washington, D.C. (Iamp;EC 17, Sunday, March 26, 9:30 a.m., Room B313A)

“Twelve Principles of Green Chemistry” — Paul T. Anastas, Ph.D., director of the ACS Green Chemistry Institute, will discuss how to use the Twelve Principles of Green Chemistry to design the next generation of nanomaterials and the transformations necessary to make them. The principles, which include the prevention of waste and the design and use of safer chemicals, are key to achieving genuine sustainability for the simultaneous benefit of the environment, economy and society, he says. (I&EC 20, Sunday, March 26, 11:45 a.m., Room B313A)

Monday March 27

Surface chemistry called key to designing non-toxic nanomaterials — Surface chemistry, not size and shape, appears to be the key feature governing the biological activity of nanoparticles, says Vicki Colvin, Ph.D., director of the Center for Biological and Environmental Nanotechnology at Rice University in Houston. This finding is being used to guide the development of greener nanomaterials that are less likely to pose health and environmental risks, she says. (I&EC 182, Monday, March 27, 8:35 a.m., Room B313A)

New water-soluble carbon nanotubes could lead to improved electronics, medicine — Researchers at the New Jersey Institute of Technology (NJIT) in Newark say they have developed a simple, quick method — using microwave energy — for developing highly water-soluble carbon nanotubes. Because the new nanotubes are up to 125 times more water soluble than other carbon nanotubes, they also are more functional for a wider variety of potential applications, including thin films, composites, faster computer chips and improved drug delivery, according to study leader Somenath Mitra, Ph.D., a professor at NJIT. (I&EC 183, Monday, March 27, 9:00 a.m., Room B313A)

Tuesday, March 28

Nanomaterials shine spotlight on cheaper, more efficient solar cells — A. Paul Alivisatos, Ph.D., co-editor of the ACS journal Nano Letters and a chemist at the University of California, Berkeley, will discuss recent efforts to develop improved solar cells using nanomaterials, which could lead to greener, cheaper and more efficient ways to generate electricity. (I&EC 228, Tuesday, March 28, 9:00 a.m., Room B313A)

Fuel cells may get efficiency boost with nanomaterials - Joseph M. DeSimone, Ph.D., a chemist at the University of North Carolina in Chapel Hill, is developing new proton exchange membranes patterned at the nanoscale that could lead to better, more efficient fuel cells. The development also may allow methanol to be used directly as a fuel source instead of hydrogen, he says. (I&EC 233, Tuesday, March 28, 11:05 a.m., Room B313A)

Wednesday, March 29

Nanosphere sensors used to detect hazardous materials — Researchers at Oklahoma State University in Stillwater have developed polymer nanospheres that can be used to detect hazardous materials in aquatic environments near parts per billion levels. The sensors, which change their shape and optical properties depending on the chemical that is present, can be read by optical spectroscopic techniques to identify the chemical, the researchers say. (I&EC 285, Wednesday, March 29, 1:35 p.m., Room B313B) ###

The American Chemical Society — the world’s largest scientific society — is a nonprofit organization chartered by the U.S. Congress and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.

Contact: Michael Bernstein m_bernstein@acs.org 202-872-4400 American Chemical Society

Technorati Tags: Nano or Nanotechnology and nanoparticles or Nanotech and Science or nanochemistry and American Chemical Society or environmental and nanoscale or Biological and electronics or solar cells and proton exchange membranes or polymer nanospheres

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