Researchers have developed a new method for delivering drugs using nanoparticles that shows promise in treating endometriosis, a chronic and currently incurable condition affecting about 1 in 10 women. In early testing on mice, the treatment significantly reduced symptoms and slowed disease progression after just one dose. The targeted therapy, developed by scientists at Washington State University (WSU), uses niclosamide—a drug approved for treating intestinal tapeworms—to target specific cells involved in endometriosis. The results were published in the journal Advanced Healthcare Materials, and the team is now working toward human trials. Endometriosis is a condition where tissue similar to the lining of the uterus grows outside the uterus, leading to chronic pain, severe cramps, pain during sex, and infertility. It affects around 190 million women globally, and many face years of undiagnosed suffering. Current treatments, such as hormonal therapies, help manage symptoms but can cause side effects like reduced fertility and bone density loss. Surgery can remove lesions, but the benefits are often temporary. Recent research has focused on the role of the immune system, particularly a type of white blood cell called macrophages, in endometriosis. A previous study by WSU scientists identified a specific group of macrophages linked to the disease, making them a potential target for drug delivery. Niclosamide has previously shown potential in reducing endometriosis lesions, but its low solubility means patients must take large doses, which can be unsafe over time. To overcome this challenge, the WSU team engineered a nanosized molecule called a dendrimer to bind with niclosamide, improving its solubility and delivery. In a mouse study, a single injection of this nanocarrier significantly reduced lesion size and number, as well as pain sensitivity. The research was led by Kanako Hayashi, a professor at WSU, and Anjali Sharma, now at the University of Michigan, along with several other researchers. The team is now working with WSU’s Office of Entrepreneurship and Innovation to pursue patents and move toward human trials. If the nanocarrier remains stable for a month, patients could receive the treatment once a month via injection. The study was titled "2-Deoxyglucose Dendrimer-Enabled Niclosamide Delivery to FRβ-Expressing Macrophages Alleviates Endometriosis Progression and Associated Hyperalgesia."