Approximately 14 percent of the world's population suffer from dry eye disease (DED) but treatments are limited because it's difficult to model the complex human eye for drug development. Now though, University of Pennsylvania bioengineers developed an "eye-on-a-chip" complete with a motorized blinking eyelid. The hope is that the artificial eye will lead to a deeper understanding of dry eye disease, enable drug screening, and even become a testbed for contact lens technology and eye surgery. Their technology also received the 2018 Lush Prize awarded for innovations that could help eliminate animal testing for shampoos and other beauty product. From Eurekalert:
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In this study, (Dan) Huh and (Jeongyun) Seo focused on engineering an eye model that could imitate a healthy eye and an eye with DED, allowing them to test an experimental drug without risk of human harm.
To construct their eye-on-a-chip, Huh's team starts with a porous scaffold engineered with 3D printing, about the size of a dime and the shape of a contact lens, on which they grow human eye cells. The cells of the cornea grow on the inner circle of scaffolding, dyed yellow, and the cells of the conjunctiva, the specialized tissue covering the white part of human eyes, grow on the surrounding red circle. A slab of gelatin acts as the eyelid, mechanically sliding over the eye at the same rate as human blinking. Fed by a tear duct, dyed blue, the eyelid spreads artificial tear secretions over the eye to form what is called a tear film.
More than 100 hours of MIR scanning has generated an image of a whole human brain with unprecedented level of detail. Massachusetts General Hospital researchers and their colleagues used a 7 Tesla MRI machine, recently approved by the FDA, to scan the donated brain from a 58-year-old-woman. The image shows detail down to .1 millimeter. From Science News:
Before the scan began, researchers built a custom spheroid case of urethane that held the brain still and allowed interfering air bubbles to escape. Sturdily encased, the brain then went into a powerful MRI machine called a 7 Tesla, or 7T, and stayed there for almost five days of scanning...
Researchers can’t get the same kind of resolution on brains of living people. For starters, people couldn’t tolerate a 100-hour scan. And even tiny movements, such as those that come from breathing and blood flow, would blur the images...
These (new kinds of) detailed brain images could hold clues for researchers trying to pinpoint hard-to-see brain abnormalities involved in disorders such as comas and psychiatric conditions such as depression.
"7 Tesla MRI of the ex vivo human brain at 100 micron resolution" (bioRxiv.org)
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The RaniPill is another syringe that you can swallow to deliver drugs to the bloodstream from the inside. It's triggered by an interesting and complex mechanism involving a chemical reaction that inflates a tiny polymer balloon to push the needle into the intestinal wall. Rani Therapeutics just completed a successful 20-person trial using a pill that shoots blanks. From IEEE Spectrum:
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Working from the outside in, the RaniPill consists of a special coating that protects the pill from the stomach’s acidic juices. Then, as the pill is pushed into the intestines and pH levels rise to about 6.5, the coating dissolves to reveal a deflated biocompatible polymer balloon.
Upon exposure to the intestinal environment, a tiny pinch point made of sugar inside the balloon dissolves, causing two chemicals trapped on either side of the pinch point to mix and produce carbon dioxide. That gas inflates the balloon, and the pressure of the inflating balloon pushes a dissolvable microneedle filled with a drug of choice into the wall of the intestines. Human intestines lack sharp pain receptors, so the micro-shot is painless.
The intestinal wall does, however, have lots and lots of blood vessels, so the drug is quickly taken up into the bloodstream, according to the company’s animal studies. The needle itself dissolves...
Participants passed the remnants of the balloon within 1-4 days.
(Founder Mir) Imran calls the device a robot though it has no electrical parts and no metal. “Even though it has no brains and no electronics, it [works through] an interplay between material science and the chemistry of the body,” says Imran.