The American Chemical Society Petroleum Research Fund has awarded a grant to study the development of molecular gears for use in future molecular machines. From an Austin College news release “ Chemist awarded $50,000 grant “ Dr. Stephanie Gould, assistant professor of chemistry at Austin College, has been awarded a $50,000 grant from the American Chemical Society to further her research on solid-state nanogears. … Gould’s research, “Synthesis of New Tunable Porous Coordination Materials to Demonstrate Geared Motion in Solid-State Materials,” focuses on building molecular “gears” for future use in nanotechnology. “I’m trying to move our world from large scale machines, like bicycles, to molecular-scale machines, moving atoms at a time,” she said. Just like a mechanical gear, these molecular gears will have cogs that will turn and fit together. “The smaller you can make a machine,” she said, “the more advanced the applications you can envision and create.” The research is on the cutting-edge of solid-state chemistry. While gears that move in liquids exist, these would be the first crystal-based gears. Possible future uses could include highly targeted nanobots to deliver a cancer drug directly to malignant cells, protecting the healthy cells from damage. It almost sounds like science-fiction. “We’re trying to figure out how much of science-fiction is real,” Gould said with a smile. Dr. Gould’s research is apparently a continuation of her postdoctoral research at the University of California, Berkeley. Work on the rotational dynamics of certain metal-organic frameworks was published in 2008 [ abstract ].
Archive for July, 2011
Dendrimers are chemically synthesized nanoparticles in which a branching monomer is polymerized to give tree-like structures organized around a central molecule, resulting in an atomically defined, more or less spherical nanostructure. The presence of many functional chemical groups on the dendrimer surface means these particles can easily be modified with molecules that provide added functionality to the dendrimer, such as molecules that target particular cells, and chemotherapy drugs as cargoes. Researchers at the University of Michigan have demonstrated in a model using immunocompromised mice (so that they do not reject human tumors) that dendrimers targeted to tumors and carrying anti-cancer drugs show great promise as potential therapy for head and neck cancer. From the National Cancer Institute Alliance for Nanotechnology in Cancer “ Polymeric Nanoparticles Attack Head and Neck Cancer “: Head and neck cancer, the sixth most common cancer in the world, has remained one of the more difficult malignancies to treat, and even when treatment is successful, patients suffer severely from the available therapies. Now, researchers at the University of Michigan have developed a tumor-targeted nanoparticle that delivers high doses of anticancer agents directly to head and neck tumors. Tests in animals have shown that this novel formulation increases survival while triggering fewer side effects. Reporting its work in the Journal of Oral and Maxillofacial Surgery [ abstract ], a team led by James R. Baker, Jr., created a spherical polymeric nanoparticle known as a dendrimer to deliver the drug methotrexate to head and neck tumors. To target the nanoparticle to those tumors, the investigators decorated the nanoparticle’s surface with folic acid. Many tumors, but few healthy cells, produce excessive amounts of a folic acid receptor on their surfaces. … The researchers tested their dendrimer-based formulation in three different groups of mice. The control group had tumors grown from human head and neck tumors that did not produce the folic acid receptor. The two experimental groups had tumors grown from human head and neck tumors that expressed moderate and high levels of the folic acid receptor. Mice receiving the equivalent of three times the normally lethal dose of methotrexate, delivered on the dendrimer nanoparticle experienced none of the weight loss normally associated with methotrexate therapy. More importantly, dendrimer-delivered therapy produced marked gains in therapeutic response even in the mice whose tumors produced only moderate levels of folic acid receptor. Some additional information on targeted dendrimer cancer therapeutics is available from the Michigan Nanotechnology Institute for Medicine and Biological Sciences, including a free review article “ Dendrimer-based nanoparticles for cancer therapy “.
Foresight’s recent past president J. Storrs “Josh” Hall was awarded the 2011 Achievement Award in the Sciences from his undergraduate alma mater Drew University: … During his subsequent graduate studies at Rutgers University, Hall found the field of nanotechnology. His first book, Nanofuture: What’s Next for Nanotechnology (Prometheus 2005), won the Foresight Institute’s Communications Prize and Drew University’s Bela Kornitzer prize. … The archive from the appearance last week on Internet radio of Foresight President Christine Peterson and Dr. Hall includes “ Some ponderings from J. Storrs Hall in the form of excerpts from his book, Nanofuture .”
A short segment of single-stranded DNA artificially evolved to bind to a particular protein growth factor has been adapted to make a molecular sensor for that factor. Upon binding the growth factor the DNA changes shape, bringing two fluorescent dye molecules closer together, thus producing an optical signal. After chemical attachment of the sensor to the membranes of an adult stem cell, and transplantation of the stem cell into a mouse where it homes to the bone marrow, the sensor reports on the environment of the cell. From EurekAlert “ Researchers provide means of monitoring cellular interactions “ Using nanotechnology to engineer sensors onto the surface of cells, researchers at Brigham and Women’s Hospital (BWH) have developed a platform technology for monitoring single-cell interactions in real-time. This innovation addresses needs in both science and medicine by providing the ability to further understand complex cell biology, track transplanted cells, and develop effective therapeutics. These findings are published in the July 17 issue of Nature Nanotechnology [ abstract ]. “We can now monitor how individual cells talk to one another in real-time with unprecedented spatial and temporal resolution,” says Jeffrey Karp, senior study author, and co-director of the Center for Regenerative Therapeutics (ReGen Rx) at BWH. “This allows us to understand signaling between cells and interactions with drugs in great detail that should have broad implications for basic science and drug discovery”. … “Once this is refined as a tool, and used to study drug interactions with cells on a regular basis, there is potential that it may be used for personalized medicine in the future,” said Weian Zhao, lead author of the study, also of the Center for Regenerative Therapeutics (ReGen Rx) at BWH. Karp adds, “We may one day be able to test a drug’s influence on cell-cell interactions before deciding on the appropriate therapeutic for each person.” … Perhaps such DNA-based nanosensors will turn out to be the predecessors of armies of nanorobots to monitor a patient’s health and the progress of her therapy.
Following up on their recent accomplishment of building a computational circuit from 74 small DNA molecules , Caltech researchers assembled 112 DNA strands into four artificial neurons that they trained with four pieces of information about four scientists. The artificial neural network can then play a game in which it properly answers questions about the identity of a scientist that the player has in mind even when the player gives it incomplete or wrong information. In this way it mimics the ability of a brain to make decisions based on incomplete information. The research was published in Nature [ abstract ]. The researchers have produced videos that explain their work ( Part I: design ; Part II: experiments ). From a Caltech news release written by Marcus Woo “ Caltech Researchers Create the First Artificial Neural Network Out of DNA: Molecular Soup Exhibits Brainlike Behavior “: … Researchers at the California Institute of Technology (Caltech) have now taken a major step toward creating artificial intelligence—not in a robot or a silicon chip, but in a test tube. The researchers are the first to have made an artificial neural network out of DNA, creating a circuit of interacting molecules that can recall memories based on incomplete patterns, just as a brain can. “The brain is incredible,” says Lulu Qian, a Caltech senior postdoctoral scholar in bioengineering and lead author on the paper describing this work, published in the July 21 issue of the journal Nature. “It allows us to recognize patterns of events, form memories, make decisions, and take actions. So we asked, instead of having a physically connected network of neural cells, can a soup of interacting molecules exhibit brainlike behavior?” The answer, as the researchers show, is yes. Consisting of four artificial neurons made from 112 distinct DNA strands, the researchers’ neural network plays a mind-reading game in which it tries to identify a mystery scientist. The researchers “trained” the neural network to “know” four scientists, whose identities are each represented by a specific, unique set of answers to four yes-or-no questions, such as whether the scientist was British. After thinking of a scientist, a human player provides an incomplete subset of answers that partially identifies the scientist. The player then conveys those clues to the network by dropping DNA strands that correspond to those answers into the test tube. Communicating via fluorescent signals, the network then identifies which scientist the player has in mind. Or, the network can “say” that it has insufficient information to pick just one of the scientists in its memory or that the clues contradict what it has remembered. The researchers played this game with the network using 27 different ways of answering the questions (out of 81 total combinations), and it responded correctly each time. This DNA-based neural network demonstrates the ability to take an incomplete pattern and figure out what it might represent—one of the brain’s unique features. … This is a promising milestone on the way to developing molecular computers to function inside living cells—analyzing the molecular environment inside the cell and taking appropriate action. Paper coauthor and Caltech professor Erik Winfree and colleague Paul W.K. Rothemund won the 2006 Feynman Prizes in Nanotechnology for both the experimental work and theory categories.