Hear the biggest stories from the world of science | 4 March 2026...

What if clinicians could place tiny electronic chips in the brain that electrically stimulate a precise target, through a simple injection in the arm' This may someday help treat deadly or debilitating brain diseases, while eliminating surgery-related risks and costs. MIT researchers have taken a major step toward making this scenario a reality. They developed microscopic, wireless bioelectronics that could travel through the body's circulatory system and autonomously self-implant in a target region of the brain, where they would provide focused treatment. In a study on mice, the researchers show that after injection, these miniscule implants can identify and travel to a specific brain region without the need for human guidance. Once there, they can be wirelessly powered to provide electrical stimulation to the precise area. Such stimulation, known as neuromodulation, has shown promise as a way to treat brain tumors and diseases like Alzheimer's and multiple sclerosis. Moreover, because the electronic devices are integrated with living, biological cells before being injected, they are not attacked by the body's immune system and can cross the blood-brain barrier while leaving it intact. This maintains the barrier's crucial protection of the brain....

Inspired by the world's largest land animal, researchers have created and tested what they say is the world's smallest 3D bioprinter. The device ' which sports a 2.7-millimetre-wide printhead at the end of a long, flexible arm that moves like an elephant's trunk ' might one day assist physicians by delivering healing hydrogels after surgery. In a report published on 29 October in the journal Device1, the researchers proved that the device could be fed through a physician's surgical scope to deposit hydrogel onto an artificial set of vocal cords. 'This is the first time I've seen a bioprinter that's applicable to vocal folds,' says Ibrahim Ozbolat, a biomedical engineer at Pennsylvania State University in University Park. 'Bioprinting typically addresses skin defects from the outside. Reaching a defect internally has been a challenge in the field.' After undergoing surgery to remove cysts or growths from their vocal cords, people sometimes have difficulty speaking because their vocal folds scar and become stiff. Studies have shown that injecting hydrogels ' which can be shaped to mimic the vocal cords' natural structure and support new tissue as it grows ' boosts the healing process2. But surgeons have had a hard time delivering the biomaterials with precision because their view into the throat is limited....

Sight has never merely meant the detection of light. In almost every culture, the eye serves as a sacred symbol: the all-seeing Eye of Horus in Egypt, the divine eye of Odin in Norse mythology, and the third eye of inner knowledge in Hinduism. Like the heart, this organ carries mythological weight and has been intimately linked to the soul. But unlike the heart, vaulted away behind layers of tissue and bone, eyes are exposed, leaving them vulnerable to debris and external damage. Also, unlike the heart, the lens of the human eye has no blood vessels, no nerves, and no interaction with the immune system, meaning it cannot absorb medicines, respond to immune signals, or recover from structural injury.1 Throughout much of history, then, when an eye was damaged, there was little that could be done to heal it. And even today, ophthalmologists like myself struggle to address the idiosyncrasies of this organ when treating ocular and vision disorders. And such disorders are rampant: In 2020, an estimated 596 million people had distance vision impairment worldwide, of whom 43 million were blind. While the cause for blindness varies ' cataracts (17.01 million cases), glaucoma (3.61 million cases), trachoma2 (1.9 million cases), age-related degeneration (1.85 million cases), and more ' these diseases have enormous implications for health and economic development when taken together. Some of these problems, like age-related macular degeneration, remain difficult to treat, but others, such as cataracts, have ready and cost-effective interventions....