In Situ Sprayed Self‐Gelling Powder Self‐Assembled by a Pure Molecular Drug from Herbal Extract for Rapid Hemostasis and Neuroprotection in Traumatic Brain Injury

Abstract Immediate hemostasis and effective treatment are foremost for acute intervention in traumatic brain injury (TBI), but the therapeutic tools and professional treatment methods are often lacking at the scene. Self‐gelling powders formed by the self‐assembly of pure molecular drugs can quickly deliver hemostatic and therapeutic effects without complications from chemical modifications or additional carriers. However, no clinical drugs have been reported as a self‐gelling powder for this purpose. Here, a self‐gelling powder is self‐assembled from sodium aescinate (SA), a drug already approved for treating trauma. To generate SA self‐gelling powder (SA self‐gel‐P), SA powder is heated and cooled in an alkaline solution to form a hydrogel, then freeze‐dried and ground. The obtained SA self‐gel‐P has a good hydrophilicity. When sprayed onto the bleeding site after TBI, it rapidly absorbed blood and formed a gel through intermolecular hydrogen bonding, facilitating effective in situ sealing and rapid hemostasis. Furthermore, the formed hydrogel released SA over a long period, which helped reduce neuronal death, improve integrity of the blood‐brain barrier, reduce brain edema, alleviate neuroinflammation, and ultimately promote recovery of neurofunction without significant toxic side effects. This self‐gelling powder may serve as a powerful auxiliary tool for the pre‐hospital treatment of TBI.