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September 10, 2008

DNA origami based nanomachine for future microsurgery and neuro-imaging sensors and direct cellular interaction


Shrink-wrapped nanomachines
Making a device that operates at a scale 1000 times smaller than a human hair requires many molecular parts. A combination of DNA, silver, gold and fat molecules called liposomes are just some of the parts that will power and control a nanodevice designed to work like a remote controlled pacemaker to deliver an electrical impulse to a single cell.

A research team led by Fulton School electrical engineering professor Rudy Diaz, Biodesign Institute researcher Hao Yan (l-r) and Thomas Moore will assemble tiny nanomachines that could ultimately be used to detect and treat neurological disorders. Another funded project is John Chaput will lead a Biodesign Institute team on a project that plans to search the human genome for regions of DNA that contain important, but as of yet unidentified genetic information. If successful, Chaput’s project may confirm the possible existence of novel protein-coding regions that remain hidden in the shadows of the classic proteome. Determining how and when such proteins are made could have a major impact in diseases, such as cancer, by helping us to understand how cellular function is deposited in our genomes.

The Diaz work will be building light activated DNA devices for stimulating neurons. Hardcore Singularity related nanotechnology.

National Institute of Health has the EUREKA program. EURKA is an acronym for Exceptional, Unconventional Research Enabling Knowledge Acceleration, is intended to boost exceptionally innovative research.

Diaz’s team proposes would permit “direct interaction with cells at the local level.” That would be achieved with a nanoscale structure that could be injected into the body, targeted to attach itself to certain clusters of cells and then controlled by chemical reactions triggered by light delivered either through the skin or via microscopic optical fibers.

The team will molecularly assemble a nanodevice that is best described as a remotely powered and remotely controlled pacemaker.

It will be built on a DNA chassis that includes antennas for receiving power and commands from the outside world, and batteries to store and deliver that power.
The antennas are built of Noble metal nanospheres that take advantage of the plasmon resonance to amplify and focus light with nanometer precision.

Artificial electrocytes – electric organ cells that work like batteries, such as those that naturally occur in fish such as electric eels – will be constructed from liposomes (fat cells) that will have ion pumps and ion gate molecules incorporated into their lipid membranes.

The whole structure will have to be encapsulated in a DNA “cage” to prevent the components from being short-circuited by the body’s fluids.

Under the correct wavelength of light, the power-receiving antennae would amplify the incident light to drive the electric charging of the artificial electrocyte.
The structure would include a set of plasmonic antennae. These are microscopic metal nanostructures that behave as antennae in the presence of photons (light) the way metal antennas behave in the presence of radio waves.

The antennas would be tuned to a different wavelength and coupled to the ion gates in the membranes to serve as light-activated switches to perform a “gate-opening” process that triggers the discharge of the artificial electrocyte chain, thus delivering an electrical impulse that can stimulate neurons.

These nanostructures could lead to advanced neuro-imaging sensors operating at the cellular scale. Such nanosensors delivered to their targets by chemical tags, or during surgical intervention, could reveal new details about the transmission of neural signals and of their pathological interruption.

The light-powered artificial electrocyte could become a critical tool for improving microsurgery, and advancing the understanding of cellular biology.


Delivering the package
The device Diaz’s team proposes would permit “direct interaction with cells at the local level.” Once assembled, the nanoscale machine would be injected into the body, targeted to attach cells like neurons, and deliver an electrical impulse to stimulate a damaged region from diseases such as multiple sclerosis.s
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