A Self-Assembly Pro-Coagulant Powder Capable of Rapid Gelling Transformation and Wet Adhesion for the Efficient Control of Non-Compressible Hemorrhage

Rapid and effective control of non-compressible massive hemorrhage poses a great challenge in first-aid and clinical settings. Herein, a biopolymer-based powder is developed for the control of non-compressible hemorrhage. The powder is designed to facilitate rapid hemostasis by its excellent hydrophilicity, great specific surface area, and adaptability to the shape of wound, enabling it to rapidly absorb fluid from the wound. Specifically, the powder can undergo sequential cross-linking based on "click" chemistry and Schiff base reaction upon contact with the blood, leading to rapid self-gelling. It also exhibits robust tissue adhesion through covalent/non-covalent interactions with the tissues (adhesive strength: 89.57 ± 6.62 KPa, which is 3.75 times that of fibrin glue). Collectively, this material leverages the fortes of powder and hydrogel. Experiments with animal models for severe bleeding have shown that it can reduce the blood loss by 48.9%. Studies on the hemostatic mechanism also revealed that, apart from its physical sealing effect, the powder can enhance blood cell adhesion, capture fibrinogen, and synergistically induce the formation of fibrin networks. Taken together, this hemostatic powder has the advantages for convenient preparation, sprayable use, and reliable hemostatic effect, conferring it with a great potential for the control of non-compressible hemorrhage.

Ultrafast Killing and Self-Gelling Antimicrobial Imidazolium Oligomers

Infectious diseases and the increasing threat of worldwide pandemics have underscored the importance of antibiotics and hygiene. Intensive efforts have been devoted to developing new antibiotics to meet the rapidly growing demand. In particular, advancing the knowledge of the structure-property-activity relationship is critical to expedite the design and development of novel antimicrobial with the needed potential and efficacy. Herein, a series of new antimicrobial imidazolium oligomers are developed with the rational manipulation of terminal group's hydrophobicity. These materials exhibit superior activity, excellent selectivity, ultrafast killing (>99.7% killing within 30 s), and desirable self-gelling properties. Molecular dynamic simulations reveal the delicate effect of structural changes on the translocation motion across the microbial cell membrane. The energy barrier of the translocation process analyzed by free energy calculations provides clear kinetic information to suggest that the spontaneous penetration requires a very short timescale of seconds to minutes for the new imidazolium oligomers.