Tiny Medical Robots and Even Smaller DNA Nanobots

The two most interesting advanced biomedical development news items released last week come both from the California Institute of Technology (Caltech). Microscale devices dubbed ATOMS could one day take residence in the body, use the principles of MRI to monitor our health, and precisely release drugs. The ATOMS could be accompanied by even smaller nanoscale DNA robots able to pick up molecules and deliver them where needed.

"The dream is that we will have microscale devices that are roaming our bodies and either diagnosing problems or fixing things," notes the Caltech press release on the ATOMS. "ATOMS devices would allow you to know where they all are and talk to all of them at once." The researchers say the devices are still preliminary but could one day serve as miniature robotic wardens of our bodies, monitoring a patient's gastrointestinal tract, blood, or brain.

The Caltech developers of DNA molecular machines want to extend their work toward general-purpose DNA robots, and mention exciting new applications, "such as using a DNA robot for synthesizing a therapeutic chemical from its constituent parts in an artificial molecular factory, delivering a drug only when a specific signal is given in bloodstreams or cells, or sorting molecular components in trash for recycling."

ATOMS: mIcro-MRI stations for diagnostic and therapeutical applications. Scientists at Caltech have developed a prototype miniature medical device that could ultimately be used in "smart pills" to diagnose and treat diseases. A study published in Nature Biomedical Engineering describes the device, dubbed ATOMS (Addressable Transmitters Operated as Magnetic Spins). Borrowing from the principles of magnetic resonance imaging (MRI), ATOMS contain integrated sensors, resonators, and wireless transmitters to precisely locate themselves in a patient’s body and relay information back. The devices could also be instructed to release drugs at precise locations.

DNA molecular machines perform housekeeping tasks at the nanoscale. Scientists at Caltech have developed an autonomous molecular machine that can perform various housekeeping tasks and deliver cargo at the nanoscale. The nanomachines, made of a single strand of DNA, can autonomously walk around a surface, pick up certain molecules and drop them off in designated locations. A study published in Science, shows how the molecular robot could explore a molecular surface, pick up two different molecules - a fluorescent yellow dye and a fluorescent pink dye - and then distribute them to two distinct regions on the surface. The researchers are confident that the same system design can be generalized to develop general purpose DNA robots able to, for example, precisely deliver drugs.

Understanding and controlling the molecular storage of memories. Researchers at the CNRS and other labs in Bordeaux have discovered a new mechanism for storing information in synapses and a means of controlling the storage process. A study published in Nature describes a new method to immobilize receptors at synaptic sites and provides evidence that receptor movement is essential to synaptic plasticity as a response to intense neuronal activity. According to the scientists, this is a breakthrough that moves science closer to unveiling the mystery of the molecular mechanisms of memory and learning processes, and offers new perspectives on controlling memory.

Three-protein cooperation mechanisms synchronize the release of neurotransmitters in the brain. Researchers at the Howard Hughes Medical Institute have found how three proteins help brain cells synchronize the release of chemical signals. The interaction of the three proteins, complexin, synaptotagmin, and the SNARE complex, helps groups of brain cells to quickly release chemical messages, called neurotransmitters, at the same time. The research work, published in Nature, describes the cooperation mechanism among the three proteins and could offer insight into other processes where cells secrete molecules, including insulin and airway mucus.

Does DNA come from the stars? Researchers at the University of York have shown that molecules brought to earth by meteorites could have been converted to biologically relevant carbohydrates, the ingredients for life. The research work, published in Chemical Communications, outlines a mechanism by which formaldehyde, acetaldehyde and glycolaldehyde molecules present in interstellar space, brought to earth by meteorite strikes, could potentially be converted into 2-deoxy-D-ribose, the building blocks of DNA.