Navigation Links
Cloaked DNA nanodevices survive pilot mission
Date:4/22/2014

It's a familiar trope in science fiction: In enemy territory, activate your cloaking device. And real-world viruses use similar tactics to make themselves invisible to the immune system. Now scientists at Harvard's Wyss Institute for Biologically Inspired Engineering have mimicked these viral tactics to build the first DNA nanodevices that survive the body's immune defenses.

The results pave the way for smart DNA nanorobots that could use logic to diagnose cancer earlier and more accurately than doctors can today; target drugs to tumors, or even manufacture drugs on the spot to cripple cancer, the researchers report in the April 22 online issue of ACS Nano.

"We're mimicking virus functionality to eventually build therapeutics that specifically target cells," said Wyss Institute Core Faculty member William Shih, Ph.D., the paper's senior author. Shih is also an Associate Professor of Biological Chemistry and Molecular Pharmacology at Harvard Medical School and Associate Professor of Cancer Biology at the Dana-Farber Cancer Institute.

The same cloaking strategy could also be used to make artificial microscopic containers called protocells that could act as biosensors to detect pathogens in food or toxic chemicals in drinking water.

DNA is well known for carrying genetic information, but Shih and other bioengineers are using it instead as a building material. To do this, they use DNA origami -- a method Shih helped extend from 2D to 3D. In this method, scientists take a long strand of DNA and program it to fold into specific shapes, much as a single sheet of paper is folded to create various shapes in the traditional Japanese art.

Shih's team assembles these shapes to build DNA nanoscale devices that might one day be as complex as the molecular machinery found in cells. For example, they are developing methods to build DNA into tiny robots that sense their environment, calculate how to respond, then carry out a useful task, such as performing a chemical reaction or generating mechanical force or movement.

Such DNA nanorobots may themselves sound like science fiction, but they already exist. In 2012 Wyss Institute researchers reported in Science that they had built a nanorobot that uses logic to detect a target cell, then reveals an antibody that activates a "suicide switch" in leukemia or lymphoma cells.

For a DNA nanodevice to successfully diagnose or treat disease, it must survive the body's defenses long enough to do its job. But in their current study Shih's team discovered that DNA nanodevices injected into the bloodstream of mice are quickly digested.

"That led us to ask, 'How could we protect our particles from getting chewed up?'" Shih said.

Nature inspired the solution. The scientists designed their nanodevices to mimic a type of virus that protects its genome by enclosing it in a solid protein case, then layering on an oily coating identical to that in membranes that surround living cells. That coating, or envelope, contains a double layer (bilayer) of phospholipid that helps the viruses evade the immune system and delivers them to the cell interior.

"We suspected that a virus-like envelope around our particles could solve our problem," Shih said.

To coat DNA nanodevices with phospholipid, Steve Perrault, Ph.D., a Wyss Institute Technology Development fellow in Shih's group and the paper's lead author, first folded DNA into a virus-sized octahedron. Then, he took advantage of the precision-design capabilities of DNA nanotechnology, building in handles to hang lipids, which in turn directed the assembly of a single bilayer membrane surrounding the octahedron.

Under an electron microscope, the coated nanodevices closely resembled an enveloped virus.

Perrault then demonstrated that the new nanodevices survived in the body, by loading them with fluorescent dye, injecting them into mice, and using whole-body imaging to see what parts of the mouse glowed.

Just the bladder glowed in mice that received uncoated nanodevices, which meant that the animals broke them down quickly and were ready to excrete their contents. But the animals' entire body glowed for hours when they received the new, coated nanodevices. This showed that nanodevices remained in the bloodstream as long as effective drugs do.

The coated devices also evade the immune system. Levels of two immune-activating molecules were at least 100-fold lower in mice treated with coated nanodevices as opposed to uncoated nanodevices.

In the future, cloaked nanorobots could activate the immune system to fight cancer or suppress the immune system to help transplanted tissue become established.

"Activating the immune response could be useful clinically or something to avoid," Perrault said. "The main point is that we can control it."

"Patients with cancer and other diseases would benefit enormously from precise, molecular-scale tools to simultaneously diagnose and treat diseased tissues, and making DNA nanoparticles last in the body is a huge step in that direction," said Wyss Institute Founding Director Don Ingber, M.D., Ph.D.


'/>"/>
Contact: Dan Ferber
dan.ferber@wyss.harvard.edu
617-432-1547
Wyss Institute for Biologically Inspired Engineering at Harvard
Source:Eurekalert  

Related medicine news :

1. Artificial hearts may help patients survive until transplant
2. Survive Her Affair Reviews
3. Survive Her Affair Ebook Helps Men Handle Their Wives' Affairs Properly - abb2u.com
4. Resilient Building Technology That Survived Philippines Typhoons Now Available in United States
5. Survive Water Crisis: Review Examines Damian Campbell's New Program
6. Smokers who survive to 70 still lose 4 years of life
7. Warning Labels Update Survives Dismissal in Fosamax Multidistrict Litigation: Now, AttorneyOne Can Provide Advice
8. Study shows who survives Burkitt lymphoma
9. Survived cancer? Now look out for cardiovascular risks
10. Avoiding Hospital Readmissions Boot Camp and Survive and Thrive in the Changing Health Care Environment - ABQAURP's 36th Annual Health Care Quality Conference
11. How cancer cells rewire their metabolism to survive
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Cloaked DNA nanodevices survive pilot mission
(Date:6/27/2016)... ... June 27, 2016 , ... A revolution is ... emergency ambulance transport experience for the millions of people who require these medical ... the taxi industry through the use of technology. Now, SmartEMS has put forth ...
(Date:6/26/2016)... (PRWEB) , ... June 26, 2016 , ... PawPaws ... a new product that was developed to enhance the health of felines. The formula ... , The two main herbs in the PawPaws Cat Kidney Support Supplement ...
(Date:6/25/2016)... ... June 25, 2016 , ... The temporary closing of Bruton Memorial Library on June 21 due ... up a new, often overlooked aspect of head lice: the parasite’s ability to live away ... a common occurrence, but a necessary one in the event that lice have simply gotten ...
(Date:6/25/2016)... ... ... On Friday, June 10, Van Mitchell, Secretary of the Maryland Department of ... recognition of their exemplary accomplishments in worksite health promotion. , The Wellness at Work ... Symposium at the BWI Marriott in Linthicum Heights. iHire was one of 42 businesses ...
(Date:6/24/2016)... ... , ... Marcy was in a crisis. Her son James, eight, was out of control. Prone ... physically. , “When something upset him, he couldn’t control his emotions,” remembers Marcy. “If ... at my other children and say he was going to kill them. If we ...
Breaking Medicine News(10 mins):
(Date:6/23/2016)... , June 23, 2016  MedSource announced ... as its e-clinical software solution of choice.  This ... best possible value to their clients by offering ... The preferred relationship establishes nowEDC as the EDC ... for MedSource,s full-service clients.  "nowEDC has long been ...
(Date:6/23/2016)... 2016 Any dentist who has made an implant ... process. Many of them do not even offer this as ... high laboratory costs involved. And those who ARE able to ... a high cost that the majority of today,s patients would ... Parsa Zadeh , founder of Dental Evolutions Inc. and inventor ...
(Date:6/23/2016)... Ill. , June 23, 2016  In a startling report ... are failing their residents by lacking a comprehensive, proven plan to ... a definitive ranking of how states are tackling the worst ... to only four states – Kentucky , ... Vermont . Of the 28 failing states, three ...
Breaking Medicine Technology: