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MIT researchers have developed a new method for designing 3D structures that can spring up from a flat sheet of interconnected tiles with a single pull of a string. The technique could be used to make foldable bike helmets and medical devices, emergency shelters and field hospitals for disaster zones, and much more.

Mina Konaković Luković, head of the Algorithmic Design Group at the Computer Science and Artificial Intelligence Laboratory (CSAIL), and her colleagues were inspired by kirigami, the ancient Japanese art of paper cutting, to create an algorithm that converts a user-specified 3D structure into a flat shape made up of tiles connected by rotating hinges at the corners. 

The algorithm uses a two-step method to find the optimal path through the tile pattern for a string that can be tightened to actuate the structure. It computes the minimum number of points that the string must lift to create the desired shape and finds the shortest path that connects those lift points, while including all areas of the object’s boundary that must be connected to guide the structure into its 3D configuration. It does these calculations in such a way that the string path minimizes friction, enabling the structure to be smoothly actuated with just one pull.

The actuation method is easily reversible to return the structure to its flat configuration. The patterns could be produced using 3D printing, CNC milling, molding, or other techniques.

This method could enable complex 3D structures to be stored and transported more efficiently and with less cost. Applications could include transportable medical devices, foldable robots that can flatten to enter hard-to-reach spaces, or even modular space habitats deployed by robots on the surface of Mars.

“The simplicity of the whole actuation mechanism is a real benefit of our approach,” says Akib Zaman, a graduate student in electrical engineering and computer science and lead author of a paper on the work. “The user just needs to provide their intended design, and then our method optimizes it in such a way that it holds the shape after just one pull on the string, so the structure can be deployed very easily. I hope people will be able to use this method to create a wide variety of different, deployable structures.” 

The researchers used their method to design several objects of different sizes, from personalized medical items including a splint and a posture corrector to an igloo-like portable structure. They also designed and fabricated a human-scale chair. The technique could be used to create items ranging in size from tiny objects actuated inside the body to architectural structures, like the frame of a building, that are deployed on-site using cranes.

In the future, the researchers want to further explore designs at both ends of that range. In addition, they want to create a self-deploying mechanism, so the structures do not need to be actuated by a human or robot. 

In the vision disorder amblyopia (or “lazy eye”), impaired vision in one eye early in life causes neural connections in the brain’s visual system to shift toward supporting the other eye, leaving the amblyopic eye less capable even if the original impairment is corrected. Current interventions don’t work after infancy and early childhood, when the brain connections are fully formed. 

Now a study in mice by MIT neuroscientist Mark Bear and colleagues shows that if the retina of the amblyopic eye is anesthetized just for a couple of days, those crucial connections can be restored, even in adulthood.

Bear’s team, which has been studying amblyopia for decades, had previously shown that this effect could be achieved by anesthetizing both eyes or the non-­amblyopic eye, analogous to having a child wear a patch over the healthy eye to strengthen the “lazy” one. 

The new study delved into the mechanism behind this effect by pursuing an earlier observation: that blocking the retina from sending signals to neurons in the part of the brain that relays information from the eyes to the visual cortex caused those neurons to fire “bursts” of electrical pulses. Similar patterns of activity occur in the visual system before birth and guide early synaptic development.

The experiments confirmed that the bursting is necessary for the treatment to work—and, crucially, that it occurs when either retina is targeted. After some mice modeling amblyopia had the affected eye anesthetized for two days, the researchers measured activity in the visual cortex to calculate a ratio of inputs from the two eyes. This ratio was much more even in the treated mice, indicating that the amblyopic eye was communicating with the brain about as well as the other one.

A key next step will be to show that this approach works in other animals and, ultimately, people.

“If it does, it’s a pretty substantial step forward, because it would be reassuring to know that vision in the good eye would not have to be interrupted by treatment,” says Bear. “The amblyopic eye, which is not doing much, could be inactivated and ‘brought back to life’ instead.”

As people age, their immune function weakens. Owing to shrinkage of the thymus, where T cells normally mature and diversify, populations of these immune cells become smaller and can’t react to pathogens as quickly. But researchers at MIT and the Broad Institute have now found a way to overcome that decline by temporarily programming cells in the liver to improve T-cell function. 

To create a “factory” for the T-cell-stimulating signals that are normally produced by the thymus, the researchers identified three key factors that usually promote T cells’ maturation and encoded them into mRNA sequences that could be delivered by lipid nanoparticles. When injected into the bloodstream, these particles accumulate in the liver and the mRNA is taken up by the organ’s main cells, hepatocytes, which begin to manufacture the proteins encoded by the mRNA. 

Aged mice that received the treatment showed much larger and more diverse T-cell populations in response to vaccination, and they also responded better to cancer immunotherapy treatments.

If this type of treatment is developed for human use, says Professor Feng Zhang, the senior author of a paper on the work, “hopefully we can help people stay free of disease for a longer span of their life.” 

Researchers at MIT and Microsoft have used artificial intelligence to create molecular sensors that could detect early signs of cancer via a urine test.

The researchers developed an AI model to design short proteins that are targeted by enzymes called proteases, which are overactive in cancer cells. Nanoparticles coated with these proteins, called peptides, can give off a signal if they encounter cancer-­linked proteases once introduced into circulation: The proteases will snip off the peptides, which then form reporter molecules that are excreted in urine.

Sangeeta Bhatia, SM ’93, PhD ’97, a senior author of a paper on the work with her former student Ava Amini ’16, a principal researcher at Microsoft Research, led the MIT team that came up with the idea of such particles over a decade ago. But earlier efforts used trial and error to identify peptides that would be cleaved by specific proteases, and the results could be ambiguous. With AI, peptides can be designed to meet specific criteria.

“If we know that a particular protease is really key to a certain cancer, and we can optimize the sensor to be highly sensitive and specific to that protease, then that gives us a great diagnostic signal,” Amini says. 

Bhatia’s lab is now working with ARPA-H on an at-home kit that could potentially detect 30 types of early cancer. Peptides designed using the model could also be incorporated into cancer therapeutics.

Antibody treatments for cancer and other diseases are typically delivered intravenously, requiring patients to go to a hospital and potentially spend hours receiving infusions. Now Professor Patrick Doyle and his colleagues have taken a major step toward reformulating antibodies so that they can be injected with a standard syringe, making treatment easier and more accessible. 

The obstacle to injecting these drugs is that they are formulated at low concentrations, so very large volumes are needed per dose. Decreasing the volume to the capacity of a standard syringe would mean increasing the concentration so much that the solution would be too thick to be injected.

In 2023, Doyle’s lab developed a way to generated highly concentrated antibody formulations by encapsulating them into hydrogel particles. However, that requires centrifugation, a step that would be difficult to scale up for manufacturing.

In their new study, the researchers took a different approach that instead uses a microfluidic setup. Droplets containing antibodies dissolved in a watery prepolymer solution are suspended in an organic solvent and can then be dehydrated, leaving behind highly concentrated solid antibodies within a hydrogel matrix. Finally, the solvent is removed and replaced with an aqueous solution.

Using semi-solid particles 100 microns in diameter, the team showed that the force needed to push the plunger of a syringe containing the solution was less than 20 newtons. “That is less than half of the maximum acceptable force that people usually try to aim for,” says Talia Zheng, an MIT graduate student who is the lead author of the new study.

More than 700 milligrams of the antibody—enough for most therapeutic applications—could be administered at once with a two-milliliter syringe. The formulations remained stable under refrigeration for at least four months. The researchers now plan to test the particles in animals and work on scaling up the manufacturing process.