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  • [♪ intro]

  • Every year, there are thousands of new drugs  in development at labs around the world.  

  • But only a tiny fraction of them make it through  to human trials -- never mind final approval.

  • And even among those that do get through, the  majority of new medications are actually just  

  • new-er versions of existing drugslike cheaper generic versions.

  • But there's a new hero in town with  the potential to help things along:  

  • drug discovery systems based  on artificial intelligence.

  • Even though the tech is still growing,  

  • several new drugs designed with the aid  of AI are already in clinical trials.

  • And together with other modern tech  like fully automated robot scientists,  

  • AI is changing drug discovery in  revolutionary ways -- and it's  

  • accelerating the process beyond  anything we've seen before.

  • It's only recently that we've been  able to create drugs from scratch.

  • Some drugs are based on traditional remedies  and natural products -- like aspirin

  • The first fully synthetic drugthe sedative chloral hydrate,  

  • was developed in 1869. But there was still  quite a bit of trial and error involved

  • Rather than throwing spaghetti  at the wall to see what sticks,  

  • it wasthrowing chemicals at people  to see if they stop being sick.

  • That's how, in 1932, we got sulfa drugswhen researchers at a chemical dye company  

  • discovered some of those dyes could  be used to kill dangerous microbes

  • And pure random luck also did a lot for the  early pharmaceutical industry. Most famously,  

  • if Alexander Fleming had been a little more  fastidious about keeping his lab clean,  

  • we might not have penicillin.  

  • But all that has changed. Starting in  the latter half of the 20th century,  

  • we've seen the rise of rational drug design.

  • That means no more spaghetti-throwing. Instead,  

  • scientists build drugs from the ground updriven by hypotheses of how they might work

  • Having so much data to rely on can  be a double-edged sword, though.

  • In fact, in a sense, you could say we've gotten  too good at this. The number of researchers and  

  • person-hours it takes to investigate every  single drug candidate is truly monumental.

  • But now, artificial intelligence is turning  the tables by helping to guide and accelerate  

  • this process. It's helping identify drug  candidates we might not have found otherwise,  

  • and cutting years off their development.

  • AI systems can be given a general  description of what we want to find,  

  • analyze a bunch of literature and databasesand pick out the best hits for later research.

  • This starts right at the beginning: before you  even think about how your new drug would work,  

  • you have to decide what to  design it for. You need a target.

  • That target is one of the dominoes in the sequence  

  • of things that happen in your  body to create a disease.

  • It could be a mutated gene, or an enzyme  that's working harder than it should

  • There's usually a huge body of scientific  literature devoted to the disease you want  

  • to treat -- stuff like research articlesclinical trial reports, and patient records

  • Deciding on a target based on all this information  is like looking for a needle in a haystack,  

  • and it's a lot to ask of our brains.

  • AI can help us see the big picture -- then pick  

  • out the one really specific thing  we needed from that big picture

  • AI systems use a bunch of  different technologies to do that,  

  • but generally, the key is  natural language processing.  

  • Natural language processing is basically  what allows your phone's voice assistant  

  • to understand you when you say  “Play something by Tchaikovsky.” 

  • If you're lucky, it will understand that you  want to hear any music composed by Tchaikovsky,  

  • instead of a specific piece  he wrote calledSomething.” 

  • Now, the AI doesn't really  understand what a “Tchaikovskyis.   

  • But by analyzing the relationships between  the words and the context, it can tell that  

  • you want to look forTchaikovskyin the part  of its database that holds a list of composers.

  • And the principle is the same with drug discovery.

  • So even though the AI doesn't understand what  a “geneis, if you instruct it to sort through  

  • the literature on a given disease, it  can identify the ones that stand out.

  • It can also find the places in the literature  that talk about that gene -- and look at the  

  • words connected with it. Do authors refer  to it often in the context of that disease?  

  • And crucially, do they talk  about a causal relationship?

  • If so, the AI can conclude  that that gene is worth a look.

  • Natural language processing also means that an AI  

  • system doesn't need this info to be  pre-formatted by an army of people

  • You can feed it things written by a human, like  scientific articles or medical case reports

  • So AI-based systems can analyze enormous  amounts of data and give us meaningful answers

  • And they're much faster readers than we areso they can go through way more information,  

  • and handle way more complexity, than humans alonePlus, they never need to duck out for coffee.

  • This vastly speeds up the process  of finding potential drug targets  

  • that we might have found eventuallybut it also makes it possible to find  

  • completely new targets that  we might not have noticed

  • For example, researchers at the US company Berg  

  • grew cancerous and healthy cells from  over a thousand donors in petri dishes

  • They varied the conditions and tracked  the unbelievably complex chemistry that  

  • results from cells simply doing their thing.

  • They ended up with trillions of  pieces of data from those samples.

  • That's a lot of raw info about what happens in  a cancer cell compared to a healthy one -- which  

  • is to say, too much. The amount of data  they had was so gigantic that without AI,  

  • it would have effectively been useless.

  • But their AI system was able to analyze  this data and identify various molecules  

  • that were out of whack in the cancer  cells compared to the healthy ones

  • This suggested a new cancer drug target  – a molecule called coenzyme Q10. 

  • And a new drug candidate they  developed based on that AI discovery  

  • is now in clinical trials for pancreatic  cancer and squamous cell carcinoma

  • So now we know what we want to target withnovel drug. Which means we need… a novel drug

  • Meaning it's time to identify and synthesize  

  • chemical compounds that will hopefully  hit that target in just the way we want.

  • But how do you choose what to synthesize?

  • Even before AI helpers, researchers were able  to make educated guesses about what would work,  

  • by looking at the chemical  features of substances that  

  • they already knew could interact with the target.

  • That interaction doesn't have to be beneficial  – if something sticks to your target,  

  • that gives us a clue for how to design  something new that will stick to it as well

  • But still, even if researchers know what chemical  features they want their drug candidate to have,  

  • that may still mean thousands of options.

  • And AI systems come to the rescue here as well.

  • Scientists can tell the AI what  chemical parameters they're looking for,  

  • and the system will not only  find suitable candidates,  

  • but cut the list down to those  that will potentially work best

  • The process is kind of similar to things  like using AI for image recognition.

  • When you do an image search forcats,”  

  • you may get 99 images of felines, and  one gorgeous kitten-looking cloud.

  • Because of those occasional blunders, the  AI doesn't actually make the decisions.

  • Scientists still evaluate the results,  

  • and the AI system only helps automate  and accelerate the grunt work

  • But, likethat's really helpful.

  • For example, by using AI to help choose  chemical compounds, the makers of a new  

  • candidate drug for obsessive-compulsive disorder  were able to cut down their development cycle  

  • from around five years to one, and get  their candidate into clinical trials.  

  • Once you've decided on a drug candidate  

  • and synthesized the right  chemical, it's time for testing.

  • But before human tests, and before animal  tests, researchers start with simpler assays

  • That means testing the chemical  using cultured cells or cell-free  

  • cocktails containing the drug's potential target.

  • It used to take years to do this preliminary  testing for a single potential medication

  • But in the 21st century, pharmaceutical companies  have turned to robotic high-throughput screening,  

  • which makes it possible to test hundreds  of thousands of compounds in a single day

  • A human might have to pipet the hundreds or  thousands of candidate compounds into one  

  • cell culture dish at a time, but a robot  can quickly zip through a bunch of them

  • A researcher can just design the  experiment and then check on the results.

  • Like the Voltron of modern pharmaceutical science,  

  • a bunch of autonomous capabilities can also be  combined into what's called a robot scientist

  • That system uses AI to identify specific  experiments with a lot of potential,  

  • and can then autonomously use lab  equipment to perform these experiments  

  • and fine-tune its decisions of where  to go next based on their results

  • For example, Eve, an AI-equipped robot  scientist at the University of Cambridge,  

  • has already identified a new  potential treatment for malaria.

  • Eve first identified a list of  compounds that may counteract malaria,  

  • then screened them against yeast cells in culture  to see which of those chemicals worked best.

  • This way, the Cambridge team was able  to report that Eve had identified the  

  • well-known antimicrobial compound triclosan  

  • as a candidate to help combat  treatment-resistant strains of malaria

  • Even with all of this futuristic tech, though,  

  • only a few dozen new drugs  are approved every year.

  • For example, in 2019, the US Food and Drug  Administration approved 48, but only 20 of them  

  • were actually distinct enough from existing  medications to be considered truly new

  • That's because discovering a new drug and  bringing it to market is an expensive,  

  • long and difficult process.

  • To develop one new drug candidate, researchers  need to screen up to 10,000 compounds.

  • And on average, only five of those turn out to  be good enough to go into clinical testing

  • If it gets that far, a drug candidate needs  to complete three phases of clinical trials.  

  • Of those, 90%  fail to gain FDA approval

  • And that's why developing a new  drug may take up to 15 years,  

  • and cost around 1.3 billion dollars. Each

  • But smart AI systems like the ones we've talked  about today are in a position to change that.

  • We're only beginning to see the results  of this AI revolution in drug discovery

  • There are literally hundreds of companies  

  • developing AI-based systems for  the pharmaceutical industry

  • Human scientists still drive the process. And  while machines are great at finding patterns and  

  • sorting through a lot of information in a hurryour brains can do a whole lot that machines can't.

  • But the help that AI represents  is already truly revolutionary.

  • It can cut the time and cost  necessary to develop a drug.  

  • And by doing so, it's widening that pipeline  of potentially life-saving treatments

  • When candidate drugs inevitably flunk out  -- because they don't work, or aren't safe  

  • for us to use -- this technology ensures  there will be more waiting for us to test.

  • And that's great for all of us -- even if it means  

  • the future looks kind of likerobot handing us a miracle pill.

  • We aren't robots, and we don't  have any miracle drugs handy,  

  • but what we do have are  pins for sale over at DFTBA.

  • Specifically, today is your very last chance  to grab this month's Pin of the Month -- which  

  • is of the Chandra X-ray Observatory. It's  a very charming looking little telescope,  

  • even if it kind of looks liketraffic cone laying on its side

  • Either way, this pin will only be on sale  through midnight tonight, September 30th.  

  • After that, we'll have another pin available  for pre-order and start shipping this one out!  

  • To get your hands on it, check  out the link in the description.

  • [♪ OUTRO]

[♪ intro]

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B1 中級 美國腔

我们正在教机器人和AI设计新药(We’re Teaching Robots and AI to Design New Drugs)

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    joey joey 發佈於 2021 年 05 月 19 日
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