Like Lilliputian chemists, scientists have found a way to “cork” infinitesimally small nano test tubes. The goal is a better way to deliver drugs, for example, for cancer treatment. Scientists want to fill the teeny tubes with drugs and inject them into the body, where they will seek diseased or cancerous cells, uncork and spill their therapeutic contents in the right place.
“After making the nano test tubes, we saw the potential for them to be used for drug delivery vehicles, but because they are open at one end it would be like trying to ship wine in a bottle without a cork,” said University of Florida chemistry professor Charles Martin. “You have to cork it, which is what we have accomplished.”
Martin is one of six University of Florida chemistry faculty members and graduate students who co-authored a paper about the research that appeared last month in the Journal of the American Chemical Society.
While chemotherapy works against many cancers, it can cause severe side effects such as nausea, temporary hair loss and blood disease. To make the chemo hit only the cancerous cells, Martin and scientists elsewhere have spent recent years experimenting with drug-carrying nanotubes or nanoparticles.
“Nano” stems from nanotechnology, the fast-growing science of making objects or devices that approach molecular dimensions. One nanometer equals one-billionth of a meter.
The approach makes sense for attacking diseased cells while bypassing healthy ones, but it also poses challenges. For one thing, the nanotubes must recognize their target, a problem scientists are attacking by tweaking their chemistry to make it respond to the unique chemistry of cancer cells. The tubes also must be biologically benign. Martin says a method for making nanotubes he pioneered, template synthesis, allows manufacturers to use biodegradable material, such as the polylactides that compose biodegradable sutures.
Additionally, the tubes also had to be closed at one end to form the classic test tube shape, a problem Martin and his group solved in research published in 2004.
To “cork” the test tubes in the latest research, the researchers applied an amino chemical group to the mouth of the tubes and an aldehyde chemical group to the corks. The two groups are complementary, so they bond with one another.
Billions of nanotubes could fit on a postage stamp. So, said Martin, “we don’t put individual caps in each nanotube the way corking machines do for bottles.”
Instead, the scientists immerse a small mesh that holds millions of amino-modified nanotubes, all precisely lined up in a grid pattern, into a solution imbued with millions of the corks. Brownian motion — what happens when minute particles immersed in a fluid move about randomly — takes care of the rest. The corks simply float around, then slip into the mouths of the tubes as they encounter them.
The diameter of the tubes is about 80 nanometers, or 80-billionths of a meter. Even though they are tiny, each tube can hold about 5 million drug molecules. “Each tube packs a real punch in terms of the number of drug molecules it can deliver,” Martin said.
Sang Bok Lee, an assistant professor of chemistry and biochemistry at the University of Maryland, works on similar research. He said scientists have proposed capping the tubes using chemical interactions between the drugs and the tubes. But that might not work because the tube could leak before it reaches its target.
“I strongly agree that Professor Martin’s proposed strategy will be one of the ideal solutions for the problem of controlling drug uptake and release,” he said in an e-mail.
The UF scientists aren’t there yet. There’s no easy way to unlock the amino chemical group from the aldehyde chemical group. So while Martin says there are some promising possibilities, he and his colleagues have their next job cut out for them: figuring out how to uncork the tubes.
Charles Martin | EurekAlert!
How molecules teeter in a laser field
18.01.2019 | Forschungsverbund Berlin
Discovery of enhanced bone growth could lead to new treatments for osteoporosis
18.01.2019 | University of California - Los Angeles
The scientific and political community alike stress the importance of German Antarctic research
Joint Press Release from the BMBF and AWI
The Antarctic is a frigid continent south of the Antarctic Circle, where researchers are the only inhabitants. Despite the hostile conditions, here the Alfred...
World first experiments on sensor that may revolutionise everything from medical devices to unmanned vehicles
The new sensor - capable of detecting vibrations of living cells - may revolutionise everything from medical devices to unmanned vehicles.
Dead and alive at the same time? Researchers at the Max Planck Institute of Quantum Optics have implemented Erwin Schrödinger’s paradoxical gedanken experiment employing an entangled atom-light state.
In 1935 Erwin Schrödinger formulated a thought experiment designed to capture the paradoxical nature of quantum physics. The crucial element of this gedanken...
Cellulose obtained from wood has amazing material properties. Empa researchers are now equipping the biodegradable material with additional functionalities to produce implants for cartilage diseases using 3D printing.
It all starts with an ear. Empa researcher Michael Hausmann removes the object shaped like a human ear from the 3D printer and explains:
The phenomenon of so-called superlubricity is known, but so far the explanation at the atomic level has been missing: for example, how does extremely low friction occur in bearings? Researchers from the Fraunhofer Institutes IWM and IWS jointly deciphered a universal mechanism of superlubricity for certain diamond-like carbon layers in combination with organic lubricants. Based on this knowledge, it is now possible to formulate design rules for supra lubricating layer-lubricant combinations. The results are presented in an article in Nature Communications, volume 10.
One of the most important prerequisites for sustainable and environmentally friendly mobility is minimizing friction. Research and industry have been dedicated...
16.01.2019 | Event News
14.01.2019 | Event News
12.12.2018 | Event News
18.01.2019 | Materials Sciences
18.01.2019 | Life Sciences
18.01.2019 | Health and Medicine