Come along with us to figure out how heating up testicles could be an effective male contraceptive, how ultrasounds might help us cure Type 2 diabetes, and how a robotic fish might soon clean our oceans.
Come along with us to figure out how heating up testicles could be an effective male contraceptive, how ultrasounds might help us cure Type 2 diabetes, and how a robotic fish might soon clean our oceans.
Heating up testes isn’t what you think.
Type 2 diabetes potential cure.
Robotic fish are the future.
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Find episode transcripts here: https://curiosity-daily-4e53644e.simplecast.com/episodes/hot-testes-blasting-diabetes-robo-fish-cleans-ocean
[SFX: INTRO MUSIC/WHOOSH]
NATE: Hi! You’re about to get smarter in just a few minutes with Curiosity Daily from Discovery. Time flies when you’re learnin’ super cool stuff. I’m Nate.
CALLI: And I’m Calli. If you’re dropping in for the first time, welcome to Curiosity, where we aim to blow your mind by helping you to grow your mind. If you’re a loyal listener, welcome back!
NATE: Today, you’ll learn about how heating up testicles could be an effective male contraceptive, how ultrasounds might help us cure Type 2 diabetes, and how a robotic fish might soon clean our oceans.
CALLI: Without further ado, let’s satisfy some curiosity!
[SFX: WHOOSH]
NATE: Calli, we’ve talked about male birth control before.
CALLI: Sure, I remember that. A few weeks ago we were talking about that pill that kept proteins from binding with vitamin A and making sperm, but that's not on the market yet, right?
NATE: Right, and while we wait for a solution like that, there’s really only two viable methods for male contraception - condoms and vasectomies. But both have downsides. Condoms can break and some men are allergic to latex, and vasectomies are full blown surgical procedures that can be painful and tricky to reverse.
CALLI: So in the meantime, are we just waiting for that vitamin A pill?
NATE: Well researchers are investigating another method called nano-contraception that relies on heat to cause temporary sterility. The good news is the early results from trials are promising.
CALLI: Nano? They might need to work on the branding a bit.
NATE: The idea is to deliver nanoparticles to the testicles to switch sperm production off. Each particle would be just a hundred nanometers, or one-thousandth the width of a human hair.
CALLI: How do researchers “deliver” these nanoparticles?
NATE: The first study from 2013 used direct testicle injections in mice. In these trials researchers used gold nanoparticles, think small tubes of just 120 atoms of gold linked together.
CALLI: But how would such small particles turn off fertility?
NATE: The trick is simple: heat. They used the nanoparticles to warm the testicles. As the temperature of the testicles rise, they become less fertile.
CALLI: So how did they raise the temperature of these gold nanoparticles then?
NATE: Once they were in the testicles, researchers used infrared radiation to raise their temperature an additional fifteen to thirty degrees Fahrenheit. Unfortunately, in that study the radiation also caused heat marks, and researchers concluded that it must have been…pretty painful.
CALLI: What do they think went wrong?
NATE: Getting the right temperature is a really precise metric. If the temperature of the testicles rises too much it can kill tissue. That means even when they return to a normal temperature, they’d be unable to produce sperm.
CALLI: I think we might have just convinced some folks to wait for the Vitamin A pill.
NATE: Hang in there. A second study from the same team in 2021 had much more promising results. This time the researchers injected nanoparticles made of iron oxide instead of gold into the mice’s veins, rather than their testicles.
CALLI: But if the particles were injected into the mice’s veins, how did they get them to the testicles?
NATE: Unlike gold, iron is magnetic. After the injection, the team placed a magnet next to the mice’s testicles for about four hours to draw the particles in. Depending on the research group, they’d repeat this injection and magnetization process once a day for one to four days.
CALLI: Ok, so they moved the particles to the testicles but how do they heat them up without burning the mice?
NATE: After a mice’s last day of the process, they wrapped an electric coil around the testicles and ran a current through it to activate a magnetic field. This magnetic field, rather than infrared radiation, caused the nanoparticles to heat up. The more days a mouse had undergone the injection-magnetization process, the hotter the temperature rose.
CALLI: But…what does that do to a set of testicles?
NATE: Over seven days after treatment, fertility decreased and some mice even saw fertility completely eliminated. Importantly though, it wasn’t permanent. The fertility gradually recovered over the next sixty days.
CALLI: How did it affect the testicles? Did they burn? Did they look different?
NATE: The mice looked healthy. The increased temperatures actually led to some shrinking… it wasn’t permanent, though. They showed recovery about thirty to sixty days after the treatment.
CALLI: Ok, so the males recovered, and looked normal again, but was there any effect on their offspring when they reproduced?
NATE: Interestingly, the litter sizes were completely normal and none of the babies showed any signs of defects.
CALLI: So it works, that’s pretty cool. But is it totally safe?
NATE: That’s what it looks like. The team found that the iron-based particles even eventually flushed out of the mice’s bodies entirely through their livers and spleens. Those gold particles from the previous study stayed in the body forever.
CALLI: Alright I was a bit suspicious at first, but this actually sounds pretty good. When are we going to see it hitting urology offices across the country?
NATE: Well, we probably won’t. Researchers say it’ll likely stay in the animal kingdom for things like controlled breeding in zoos or as an effective but reversible alternative breeding control in pets. In fact, nano-contraception is already being used on some domestic cats in China for owners looking to avoid the cost of more invasive surgeries.
CALLI: Well I guess human men will have to keep hoping for that Vitamin A pill.
NATE: It's a great step though, it opens doors for creative new solutions for male contraception in humans down the road, and that's an area where us men are long overdue for pitching in and helping bear the burden of responsible sex.
[SFX: WHOOSH]
CALLI: Nate, are you familiar with ultrasounds?
NATE: Totally, some of my friends have started posting those fuzzy black and white pictures on social media as pregnancy announcements.
CALLI: Well ultrasounds aren’t just for scanning pregnancies to check on development anymore. A new study is showing promise in using ultrasounds to help manage type two diabetes.
NATE: Wait wait, but how does an image of something help us manage it?
CALLI: Ultrasounds can do more than just make images! But first let's clarify what an ultrasound actually is. Ultrasounds are a group of sound waves that are so high in frequency, humans can’t hear them. For decades scientists have used these soundwaves, and the echos they create as they hit things within our body, for imaging, but now researchers are looking to see whether they could be used to affect our body as well.
NATE: Soundwaves having an affect on us? What would that look like?
CALLI: Think smaller! Scientists have recently started all kinds of studies into whether or not these sound waves could be used to fight diseases, from breaking up kidney stones to attacking problematic cells in Parkinson’s patients, and even potentially heating and killing cancerous prostate cells.
NATE: So the sound waves are actually powerful enough to affect our cells and break up things in our body?
CALLI: Yep! But for this study rather than breaking up a clump of calcium or cooking cancer cells, researchers tried to treat type 2 diabetes. They used the ultrasound to stimulate blood sugar regulating nerve endings in the livers of mice, rats, and pigs.
NATE: I thought diabetes was caused by issues in the pancreas?
CALLI: The pancreas is definitely the major organ involved in the condition, but the liver plays an important role as well. It’s the key regulating organ of our body and researchers looked specifically at an area of the liver called the porta hepatis.
NATE: What does that do?
CALLI: It has a specific nerve network that tells the brain about the status of our blood sugar. Researchers hoped that stimulating it might allow the nerve network to better communicate blood sugar levels of type 2 diabetes patients to the brain. But this network is tiny. Like really small. So small that our older technology wasn’t precise enough to stimulate.
NATE: But a standard ultrasound could? Haven’t we had that for decades?
CALLI: It’s actually a different kind of ultrasound than those imaging scans. The study used “Peripheral Focused Ultrasound Stimulation” or pFUS for short, which creates pulses of sound waves that researchers hoped would be precise enough to reach the small nerve network.
NATE: Well, did it work?
CALLI: Yes! They carefully directed the pFUS to stimulate the nerve network and found that after only three minutes of stimulation, the treatment helped the body maintain normal blood sugar levels.
NATE: But that's in animals, right? Will it work in humans?
CALLI: The human applications for this technology are still pretty far off, remember this study was on mice, rats, and pigs. The biggest hurdle is that pFUS ultrasounds have to be operated by a trained technician.
NATE: Driving to the hospital every day, even for a three minute treatment, would be such a pain.
CALLI: The good news is that it’s definitely possible to build more simplified versions of the ultrasound that could be used at home, maybe even automated. And we’ve already moved to human trials.
NATE: When will we get the first results?
CALLI: As early as later this year. But these will be preliminary, so we’ve got a ways to go before we have anything concrete.
NATE: If it goes well, what does that mean for people with diabetes? A life free of drug treatments?
CALLI: There’s still a lot of research to be done on the possible side effects of organ stimulation. Some think it could cause the organs to release unwanted hormones or enzymes, and we really don’t know what that might do to our bodies. But the research is worth pursuing, insulin prices are rising, and many insulin lowering drugs become less effective over time.
NATE: So we have some hope.
CALLI: Absolutely. Some researchers think this might even be the first step down the path to reversing type 2 diabetes.
[SFX: WHOOSH]
CALLI: Nate, I’ve got some good news about cleaning up our waterways. Do you remember how we recently talked about microplastics?
NATE: I do, but remind me again what exactly they are and why they’re a problem?
CALLI: Microplastics are tiny plastic particles no bigger than 5mm across that break off of bigger plastic things we use every day like water bottles, jugs, or synthetic T-shirts. They’re an enormous environmental issue because once they splinter off into the water, they’re next to impossible to dispose of, let alone find.
NATE: So then where is the good news?
CALLI: While microplastics have been particularly hard to deal with in our oceans, scientists recently created a ROBOT FISH that can attract microplastics in the water and remove them from the ecosystem.
NATE: How do you make a robot fish? What would a swimming mechanism even look like for that?
CALLI: Researchers were inspired by the durable inner layer of pearl-making clams, the material is called mother of pearl and it's really tough stuff. So the researchers copied its structure to make a material that was both strong and flexible, then used it to build a small fish, only 13mm long! The fish is self propelled and uses near infra-red lasers to rapidly flap its tail which helps it move forward at an inch per second. That doesn’t sound like much but it's about how fast plankton drifts in the water. The robo fish can bend and wiggle through the water and is even strong enough to pull about 11 pounds.
NATE: That’s impressively strong for such a small fish.
CALLI: Well it needs that strength to deal with all the plastic! That’s because researchers designed the exterior of the fish to attract microplastics by creating chemical bonds in the materials of some of the plastics, and grabbing onto others with an electrical attraction like static cling! So as it swims, it collects tons of tiny microplastics!
NATE: Oh that's so cool. Like a microplastic magnet. It must be pretty rough on those little fish, swimming through all that junk in the water, though.
CALLI: Totally, it's dangerous work to float through the ocean collecting microplastics. Incredibly though, one of the creators specializes in creating regenerative materials, which means materials that can actually fix or “heal” themselves. In simpler terms, it means if the little fish gets cut or something, that new mother-of-pearl-like material can fix itself to about 89% of its original capabilities!
NATE: This little thing sounds like a superhero! Can I get my own?
CALLI: Unfortunately, this experiment is just a proof of concept at the moment to show how effective a robo-fish might be. There’s still a lot of research that needs to be done, especially to make sure it could work in the rough waters of the real world. Right now, the fish only works on the surface of the water and can’t dive. Still, it's incredibly great news - that gives us hope in removing microscopic pollutants from the water. And could lead to better, more effective experiments in the future.
NATE: Ah, I just don’t want to wait for these solutions!
CALLI: Don’t worry Nate, microplastics is an issue many researchers are concerned with. I’m sure this won’t be the last story we hear about using science to try to solve this pervasive problem.
[SFX: WHOOSH]
NATE: Let’s recap what we learned today to wrap up. Ultrasound technology isn’t just for early baby photos anymore. New technology hopes to use pulsing sound waves, at frequencies too high for the human ear, to stimulate nerves in the liver to help our bodies communicate blood sugar levels to the brain. If it's successful, it could revolutionize treatment of, and potentially reverse, type 2 diabetes.
CALLI: A new study is showing that when it comes to making a big impact on male fertility, the solution might be small, like really small. Researchers have had early success at injecting iron nano particles into mice to raise the temperature of their testes, and temporarily decreasing their fertility.
NATE: Researchers have created a synthetic robotic fish to collect microplastics from our waterways. While it is currently just a proof of concept, its ability to attract plastics, and heal itself, is giving researchers hope for a cleaner future.