Nanotech News: Tiny Propellers for Drug Delivery

NanopropellersThe scientific and medical research communities have been looking to develop robots that measure in the nanometer range (that’s one-billionth of a meter) for quite some time. Being so small, they would be able to perform difficult tasks, such as targeted drug delivery to specific cells, or the elimination of harmful antigens, pathogens or viruses. However, the development of such machines raises numerous challenges.

For one, making them small enough to fit between cells remains tricky, and these tiny bots would also need a propulsion system that will allow them to navigate their way through the human body. But now, in a paper published in the June 2014 issue of ACS Nano, an Israeli and German team announced the creation of the smallest nanobot yet, a magnet-guided corkscrew which is propelled by a tiny helical propeller.

Nanopropellers1The team is comprised of researchers from the Technion-Israel Institute of Technology, the Max Planck Institute for Intelligent Systems, and the Institute for Physical Chemistry at the University of Stuttgart, Germany. Led by Dr. Peer Fischer at the Max Planck Institute, the research team created the tiny helical nanopropeller from a filament of silica and nickel that measures just 70 nanometers in diameter and 400 in length.

That’s more than 1,000 times smaller than the width of a human hair, or 100 times smaller than a single red blood cell, making the wee machine the tiniest nanopropeller humanity has ever created. Instead of carrying its own motor, the propeller is powered by an externally-applied weak rotating magnetic field which causes the prop to spin, driving it and its attached payload forward.

nanotech-2In order to test it, the scientist placed it in a hyaluronan gel, which is similar in consistency to bodily fluids. Like those fluids, the gel contains a mesh of entangled long polymer protein chains. In previous studies, larger micrometer-sized propellers got caught in these chains, slowing or completely halting their progress. The new nanoprop, however, was able to move relatively quickly by simply passing through the gaps in the mesh.

The study’s co-author, Associate Professor Alex Leshanksy of the Technion Faculty of Chemical Engineering, said that the nanobots:

actually display significantly enhanced propulsion velocities, exceeding the highest speeds measured in glycerin as compared with micro-propellers, which show very low or negligible propulsion.

The applications for this device certainly include targeted drug delivery, where the nanobots would be equipped with insulin, antibiotics, or even chemotherapy drugs which they could then deliver to specific cells in the body to speed up the delivery process and reduce side-effects. Scientists could also attach “active molecules” to the tips of the propellers, or use the propellers to deliver tiny doses of radiation.

nanobotsThe applications seem wide, varied, and exciting, from combating diabetes to fighting cancer and HIV with surgical precision. And developments like these, though they measure in the billionth of meters, they add up to a future where lives are healthier, longer and more prosperous.

Sources: engadget.com, gizmag.com, ats.org

An End to HIV: HIV Remove from Cultured Cells

https://i0.wp.com/292fc373eb1b8428f75b-7f75e5eb51943043279413a54aaa858a.r38.cf3.rackcdn.com/health-fitness_01_temp-1357384489-50e80b29-620x348.jpgAt the closing ceremony of the AIDS 2014 conference a few weeks ago in Melbourne, Australia, many of the speakers – including longtime AIDS researcher and International AIDS Society Presidential Award winner Eric Goosby – told of how utterly terrifying the disease seemed 30 years ago. And while that fear is not gone, it has since diminished, replaced by and large with a sense of hope that the disease will be eradicated.

According to UNAIDS – the Joint United Nations Programme on HIV/AIDS, which is dedicated to destroying the disease by 2030 – the medical community has learned much in the past few years and stands a good chance at accomplishing this goal. And with new advances being announced every few months, hopes for a world in which this terrible disease no longer exists all seem firmly on track.

UNAIDSConsider this latest development, which comes from the Temple University School of Medicine in Philadelphia. Here, researchers have discovered how to permanently extricate HIV-1 from human cells, effectively curing a patient of the disease. Combined with new vaccines that have shown the ability to block infection (and in some cases, even reverse it), this news may yet be reason for even greater hope.

One of the main issues in the treatment of HIV-1 is not simply that it is expensive, but that antiretroviral therapy have terrible side effects that can speed up diseases more commonly associated with aging or can cause co-infections, such as Hepatitis C, to become worse.  Added to this is that HIV is a tricky and tenacious disease that becomes part of a patient’s DNA, making it virtually impossible to eradicate.

https://i1.wp.com/images.gizmag.com/gallery_lrg/scientistseliminatehivfromhumancells.jpgHowever, researchers from Temple University School of Medicine have found a way to cut the infected genes out, potentially eradicating the virus for good and negating the need for lifelong ARV treatment. The technique uses a DNA-snipping enzyme, a nuclease, and a targeting RNA strand to hunt down the genome and cuts the HIV-1 DNA from it. The cell is able to repair its own genomes, essentially sewing itself together again, only now HIV-free.

This treatment will work in varied cell types such as the T-cells and monocytic cells that harbor HIV. In designing the molecular tools, researchers chose nucleotide sequences that do not appear in any coding sequences of human DNA to avoid what they call off-target effects, where patient’s cells or own DNA might be damaged. The technique may also be applicable against many other viruses.

There are still serious hurdles, like how to get the treatment into each, individual cell. Also, HIV-1 is known for mutations, and every patient has their own viral sequence. This means that there can be no single, prescriptive treatment for it. However, another potential upside is that there is the chance this may be used not simply as a treatment but also a vaccine as cells containing the nuclease-RNA combination do not acquire the HIV infection.

https://i0.wp.com/www.templehealth.org/AssetMgmt/getImage.aspxDr. Kamel Khalili, Professor and Chair of the Department of Neuroscience at Temple, calls it an “important step” towards the eradication of AIDS, though it is still years away from the clinical stage. As he put it:

We want to eradicate every single copy of HIV-1 from the patient. That will cure AIDS. I think this technology is the way we can do it.

Though it is not the one-shot breakthrough many have been hoping for, this enzyme-based treatment is another step along the long road towards the end of HIV and another nail in its coffin. As long as treatments exist that are not only able to treat and block, but also fight the disease, there is much reason for hope.

And be sure to check out this video from Temple University, where Dr. Khalili explains the medical breakthrough:


Sources:
gizmag.com, templehealth.org