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Eliminating Drug Side Effects by Manipulating Molecular Chirality

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Dr. Jeffery Huang Zhifeng, associate professor in the Department of Physics at HKBU, has developed a novel approach to manipulating the chirality of drug molecules.

Hong Kong Baptist University

Scientists from Hong Kong Baptist University (HKBU) have developed a novel technique that can produce pure therapeutic drugs without the associated side effects.

The approach, which uses a nanostructure fabrication device, can manipulate the chirality of drug molecules by controlling the direction a substrate is rotated within the device, thus eliminating the possible side effects that can arise when people take drugs containing molecules with the incorrect chirality.

Published in the scientific journal Nature Chemistry, the research findings pave the way towards the mass production of purer, cheaper, and safer drugs that can be made in a scalable and more environmentally-friendly way.

Control of molecular chirality improves drug safety

Many chemical molecules have two configurations, or chiral versions, that are mirror images of each other. While sharing the same molecular formula, the two chiral versions have different arrangements of their constituent atoms in space. The two versions of the molecules are characterized by left-handed and right-handed chiral configurations like human hands. Molecules with “left-handed” and “right-handed” chirality can have totally different biochemical effects.

More than half of the therapeutic drugs are made up of equal amounts of left-handed and right-handed chiral molecules, commonly known as “racemates;” one can cure specific diseases, but the other may have adverse effects. Separating and producing molecules with only the chiral arrangement (known as a single enantiomer) responsible for the therapeutic effects can help to produce drugs with improved safety and efficacy.

Macro-scale control of molecular chirality

In general, molecules have an extremely small size ranging from one-millionth to one hundred-thousandth of the diameter of a human hair. It is therefore extremely challenging to selectively produce one of the two chiral molecule versions using “macro-scale” control (i.e. the dimensional scale that can be seen using the naked eye and operated by hand). To produce single-enantiomer drugs, chemists have overwhelmingly used molecules called “chiral ligands” to effectively control the molecular chirality of drugs in the laboratory or industry at the molecular scale, a process called asymmetric synthesis. However, the existing technologies for producing single-enantiomer drugs are composed of complicated procedures, which are expensive and environmentally-unfriendly.


Dr. Jeffery Huang Zhifeng, associate professor in the Department of Physics at HKBU, and his research team devised a novel approach to manipulating molecular chirality through macro-scale control in collaboration with Sichuan University, Guangxi Medical University and the Southern University of Science and Technology. It involves mediating the manipulation with helical metal nanostructures (i.e. metal nanohelices) that are in the shape of a helical spring, and they have a characteristic size of one-thousandth of the diameter of a human hair.

Direction of rotation determines molecular chirality

The research team fabricated the metal nanohelices using a nanofabrication technique called glancing angle deposition (GLAD). Silver and copper were deposited onto a supporting substrate that was rotated clockwise and counterclockwise to fabricate the right-handed and left-handed metal nanohelices, respectively.

The research team then used ultraviolet light to induce a chemical reaction. This caused 2-anthracenecarboxylic acid (AC) molecules adsorbing on the metal nanohelices to undergo the chemical reaction and form chiral molecular products, which are similar to some chiral drugs. When AC was attached to the surface of the right-handed metal nanohelices and exposed to ultraviolet light, it preferentially produced “right-handed” chiral molecular products. By the same token, when AC was adsorbed on the surface of the left-handed metal nanohelices and exposed to ultraviolet light, it preferentially produced “left-handed” chiral molecular products. In other words, the chirality of the molecular product can be reliably determined by the chirality of the metal nanohelices, which is controlled by the direction of substrate rotation.

The research demonstrates that controlling the direction of substrate rotation at a macroscopic level can conveniently manipulate molecular chirality. This is an unprecedented application of the macro-scale method (through the control of the rotation direction of a 4-inch substrate holder) to manipulate chirality at the molecular-scale (chiral molecular products in the range of one-billionth of a meter).

Green approach to reducing drug side effects

“Our success in manipulating molecular chirality through macroscopic engineering allows the convenient synthesis of drugs in single-enantiomer forms with only left- or right-handedness. Hence, it will help get rid of the adverse, sometimes fatal, side effects of many therapeutic drugs,” said Huang.

The use of chiral ligands in the conventional method of asymmetric synthesis is inevitable, and it may cause pollution to enter the environment. In contrast, in this novel approach the metal nanohelices can be used repeatedly to produce single-enantiomer drugs without the use of chiral ligands. As a result, it paves the way towards the mass production of affordable therapeutic drugs that are made in a scalable manner with recyclable materials.

This press release was originally published on the Hong Kong Baptist University website

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Elon Musk's SpaceX prepares for upcoming astronaut mission to International Space Station – National Post

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CAPE CANAVERAL — Entrepreneur Elon Musk’s SpaceX is set to launch two American astronauts to the International Space Station on Wednesday from NASA’s Kennedy Space Center in Florida, ending the U.S. space agency’s nine-year hiatus in human spaceflight.

California-based SpaceX’s Crew Dragon capsule carrying astronauts Doug Hurley and Bob Behnken and its Falcon 9 rocket is due to lift off at 4:33 p.m. EDT (2033 GMT) on Wednesday from the same launch pad used by NASA’s last space shuttle mission in 2011.


NASA astronauts Bob Behnken (second from left) and Doug Hurley (right) walk with NASA Administrator Jim Bridenstine (left) and Robert Cabana (second from right), the director of NASA’s John F. Kennedy Space Center, after arriving at the Kennedy Space Center on May 20, 2020 in Cape Canaveral, Florida. The astronauts arrived for the May 27th scheduled inaugural flight of SpaceX’s Crew Dragon spacecraft.

Joe Raedle/Getty Images

President Donald Trump and Vice President Mike Pence will view the launch in person, a White House spokesman said.

For Musk, SpaceX and NASA, a safe flight would mark a milestone in the quest to produce reusable spacecraft that can make space travel more affordable. Musk is the founder and CEO of SpaceX and CEO of Tesla Inc.

“Bob and I have been working on this program for five years, day in and day out,” Hurley, 53, said as he and Behnken, 49, arrived at the Kennedy Space Center from Houston last week. “It’s been a marathon in many ways, and that’s what you’d expect to develop a human-rated space vehicle that can go to and from the International Space Station.”


This NASA TV video frame grab shows a SpaceX in-flight abort test on January 19, 2020 at the Kennedy Space Center, Florida. SpaceX simulated its emergency abort system in January on an unmanned spacecraft, the last major test before it plans to send NASA astronauts to the International Space Station. The space company launched its Crew Dragon capsule from the Kennedy Space Center in Florida at 10:30 am (1530 GMT) to check the capsule’s ability to reliably carry crew to safety in the event of an emergency on ascent.

HANDOUT/NASA TV/AFP via Getty Images

NASA, hoping to stimulate a commercial space marketplace, awarded $3.1 billion to SpaceX and $4.5 billion to Boeing Co. to develop duelling space capsules, experimenting with a contract model that allows the space agency to buy astronaut seats from the two companies.

Boeing’s CST-100 Starliner capsule is not expected to launch its first crew until 2021.

NASA Administrator Jim Bridenstine declared the mission a “go” last week at Kennedy Space Center after space agency and SpaceX officials convened for final engineering checks.

SpaceX successfully tested Crew Dragon without astronauts last year in its first orbital mission to the space station. That vehicle was destroyed the following month during a ground test when one of the valves for its abort system burst, causing an explosion that triggered a nine-month engineering investigation that ended in January.

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Musk's SpaceX set for debut astronaut mission, renewing NASA's crewed launch program – Cape Breton Post

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By Joey Roulette

CAPE CANAVERAL, Fla. (Reuters) – Entrepreneur Elon Musk’s SpaceX is set to launch two American astronauts to the International Space Station on Wednesday from NASA’s Kennedy Space Center in Florida, ending the U.S. space agency’s nine-year hiatus in human spaceflight.

California-based SpaceX’s Crew Dragon capsule carrying astronauts Doug Hurley and Bob Behnken and its Falcon 9 rocket is due to lift off at 4:33 p.m. EDT (2033 GMT) on Wednesday from the same launch pad used by NASA’s last space shuttle mission in 2011.

President Donald Trump and Vice President Mike Pence will view the launch in person, a White House spokesman said.

For Musk, SpaceX and NASA, a safe flight would mark a milestone in the quest to produce reusable spacecraft that can make space travel more affordable. Musk is the founder and CEO of SpaceX and CEO of Tesla Inc.

“Bob and I have been working on this program for five years, day in and day out,” Hurley, 53, said as he and Behnken, 49, arrived at the Kennedy Space Center from Houston last week. “It’s been a marathon in many ways, and that’s what you’d expect to develop a human-rated space vehicle that can go to and from the International Space Station.”

NASA, hoping to stimulate a commercial space marketplace, awarded $3.1 billion to SpaceX and $4.5 billion to Boeing Co to develop dueling space capsules, experimenting with a contract model that allows the space agency to buy astronaut seats from the two companies. 

Boeing’s CST-100 Starliner capsule is not expected to launch its first crew until 2021.

NASA Administrator Jim Bridenstine declared the mission a “go” last week at Kennedy Space Center after space agency and SpaceX officials convened for final engineering checks.

SpaceX successfully tested Crew Dragon without astronauts last year in its first orbital mission to the space station. That vehicle was destroyed the following month during a ground test when one of the valves for its abort system burst, causing an explosion that triggered a nine-month engineering investigation that ended in January.

(Reporting by Joey Roulette in Washington; Editing by Greg Mitchell and Will Dunham)

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SpaceX on the verge of sending astronauts into orbit – Financial Times

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If Elon Musk’s SpaceX succeeds in sending two astronauts into orbit for the first time this week, it will do more than just boost the bragging rights of one of the world’s best-known billionaires.

As the first human test flight on a commercial rocket to reach the International Space Station, it will also signal a breakthrough for the private space industry as a whole, and an important moment in the opening up of low earth orbit to the commercial sector.

The first manned test for the Crew Dragon capsule, carrying two Nasa astronauts on top of one of SpaceX’s Falcon 9 rockets, is scheduled to lift off from the Kennedy Space Center in Florida on Wednesday morning.

If the flight to the ISS is successful, Nasa is expected to buy four seats on a follow-up flight later this year, the first time its astronauts will have become paying passengers on a commercially owned and operated space vehicle.

This week’s launch marks the moment when the private sector starts to lift humans off the face of the planet “reliably and cheaply”, said Peter Diamandis, founder of the X Prize, the competition which led to the first private manned flight to the edge of space 16 years ago. “It’s the first, fully commercially built, entrepreneurial capability,” he said. “What Elon Musk has done is nothing short of extraordinary, outpacing the US government-backed industries, Russia and China.”

Many of the technologies that SpaceX is relying on were pioneered by government space programmes over the past 60 years, meaning that the company is “standing on the shoulders of giants”, said Greg Autry, a former White House liaison to Nasa and an expert on the private space sector.

He compared the commercialisation of human space flight with the moment when the internet, which was created by the US Defense department, was handed over to the private sector. That makes the test flight a “tipping point we’ve been waiting for in the commercial space industry for a number of years”, he said.

Nasa, which commissioned both SpaceX and Boeing seven years ago to build human launch systems, is counting on commercial incentives and market competition to drive down the price of getting into space. It has estimated that the $400m SpaceX spent to develop its Falcon 9 rocket, which has become the workhorse for lifting cargo to the ISS, was only a tenth what it would have cost Nasa itself to build a similar rocket.

Since the Space Shuttle was retired in 2011 and the US was forced to buy seats on Russian rockets to propel its astronauts to the ISS, the cost of getting into space has risen sharply. Dennis Tito, the first space tourist, paid $20m in 2001 for a ride to the ISS on a Russian rocket. The price of a seat has now ballooned to more than $90m.

A competitive commercial market could quickly push that price back below $50m, said Mr Autry. Boeing’s rival space capsule suffered a setback earlier this year because of software glitches but is expected to make its first manned test launch next year. Other companies, including Jeff Bezos’s Blue Origin and Sierra Nevada, a Californian company that has built a space vehicle with wings, also hope to cash in.

As competition increases and the process for mounting human flights becomes more streamlined, the price for a trip into orbit could fall below $10m over the next decade, Mr Autry predicted.

All of this remains theoretical, however, until private companies prove they can launch humans into orbit safely, and return them to earth. The thought of entrusting astronauts to a fully commercial rocket company was jarring for many in the US space programme when it was first proposed in 2011, said Janet Kavandi, a former Nasa astronaut and now an executive at Sierra Nevada.

Nasa worked hard to make sure companies such as SpaceX are ready, she added. That meant doing everything from sharing the data from its Columbia shuttle disaster to teaching them everything it had learnt about crew survivability, down to the way seats are attached to the craft. By opting for a capsule, rather than a winged craft such as the Space Shuttle, SpaceX has also reduced the complexity of its launches.

Technical illustration showing some of the details of spaceX's Crew Dragon capsule and Falcon 9 launcher

Many in the private space industry believe demand is pent up to support the new human launch companies in their early years, though few are prepared to guess at the ultimate size of the market.

Countries that have space programmes but don’t have their own launch systems are already waiting to buy seats on private rockets, said Laura Forczyk at Astralytical, a US space consultancy. A boom in space tourism is likely to follow, she added, particularly if prices fall as fast as some expect.

Nasa, which objected to Mr Tito’s private flight nearly two decades ago, has since become a strong backer of space tourism as a way to share some of its own costs and shift more of its budget to reach the moon and, eventually, Mars. Last year it went as far as to publish a detailed price list for use of its facilities on the ISS, including $11,250 a day for private astronauts to access the station’s life support system and toilet.

The next step in commercialising space will need more accommodation for private astronauts, particularly since the ISS is due to be retired sometime this decade. The first private company to launch a module designed to attach to the ISS, Axiom, hopes to launch in 2024, on the way to a fully freestanding space station. The full potential of low earth orbit also depends on the private sector seizing on the chance to carry out materials research and manufacturing in zero-gravity — an idea that has barely been tested.

For Mr Musk, meanwhile, the first private trip some 250 miles up to the ISS is only a small step to a far more ambitious goal. Turning humanity into an interplanetary species is still his overriding ambition in life, said Mr Diamandis. “It means that we now have an entrepreneurial company that will also get us to the moon, and eventually to Mars,” he said.

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