Zinc Metal–Organic Framework@Chitin Composite Sponge for Rapid Hemostasis and Antibacterial Infection

Abstract

Uncontrollable bleeding and bacterial infection are the two major challenges in treating hemorrhaging civilian and military traumas. Herein, a novel hemostatic material was designed by in situ growth of zinc imidazolate frameworks (ZIF-8) into a chitin sponge (CTS) for effective hemostasis and anti-infection. ZIF-8 nanocrystals were not only uniformly dispersed throughout the CTS but also firmly anchored onto CTS with a residual mass of over 94% after 10 min of sonication. The resultant composite sponge (ZIF-8−CTS) displayed a hierarchically porous structure with a high specific surface area (∼126.2 m 2 •g −1 ) and superhydrophilicity, accelerating blood absorption to concentrate blood cells and platelets to form a primary blood clot. Meanwhile, upon contact with blood, ZIF-8 nanocrystals could gradually release Zn 2+ to activate the blood coagulation cascade reactions. Benefiting from these two synergistic effects, ZIF-8−CTS exhibited superior hemostasis performance than the traditional hemostatic materials (cotton gauze and gelatin sponge) in the rat femoral artery and liver injury models. Furthermore, it displayed excellent cytocompatibility and hemocompatibility. Importantly, it had an outstanding bactericidal effect with antibacterial ratio of up to 100% for Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. These results demonstrated that ZIF-8−CTS is an excellent antibacterial hemostatic material with a high potential in clinical applications.

Fabrication of a Vitamin B12-Loaded Carbon Dot/Mixed-Ligand Metal Organic Framework Encapsulated within the Gelatin Microsphere for pH Sensing and In Vitro Wound Healing Assessment

“…From our perspective, the excellent antibacterial activity of ZIF-8 was compromised to some extent after coating with the gelatin MS. Probably, the antibacterial activity is due to the combined effects of the imidazole unit, CDs, and the Zn 2+ ion or we can say the ZIF-8 FMOF as a whole. , The imidazole scaffold retains the ability to destroy the liposomal structure of the microbial membrane . At the same time, Zn 2+ ions could adhere to the microbial membrane by improving cellular internalization and interactions with the intracellular content .…”

“…Similarly, the presence of Zn 2+ ions not only boosts wound healing mechanisms by stimulating angiogenesis, cell migration, and collagen deposition but also helps in blood coagulation and bacterial killing. 5 Thus, an efficient scaffold is required to evade vitamin's low bioavailability and release these agents sustainably. Several scaffolds have been invented for this purpose.…”

“…Most importantly, vitamin B12 actively contributes to granulation tissue construction, which is one of the essential parts of wound healing. Similarly, the presence of Zn 2+ ions not only boosts wound healing mechanisms by stimulating angiogenesis, cell migration, and collagen deposition but also helps in blood coagulation and bacterial killing …”

Design of biopolymer-based hemostatic material: Starting from molecular structures and forms

“…ZIF-8, with the high porosity and large surface area, can absorb large amounts of water. Additionally, Zn 2+ ions could rapidly release from ZIF-8 once exposed to blood, which activate the blood coagulation cascade reactions as outlined above [ 168 ]. In the same way, the hemostatic performance of chitin sponge was enhanced by combination with MXene, a booming two dimensional nanomaterials.…”

Highly Efficient Pd@CN Catalysts with Quasi-Ordered Mesopores Synthesized from Recycled Mother Liquid of Zeolitic Imidazolate Frameworks

“…Zeolitic imidazolate frameworks (ZIFs) as a special subfamily of metal–organic frameworks (MOFs) consist of transition-metal ions (such as Zn 2+ and Co 2+ ) and imidazolate linkers that form topologies similar to those of zeolites and inorganic nano-oxide materials. − By adjusting the components and modifying the functional groups, more than 150 kinds of ZIFs have been produced with different topological features. The unique structures of ZIFs inherit not only the advantages of high porosity, high specific surface area, uniform porous structures, and easy functionalization from MOFs but also the tunability and high stability from traditional zeolites, making them potentially promising for many applications in gas adsorption and separation, − chemical sensing, , biomedicine, , catalysis, − etc. As reported by Yang et al, Pd nanocubes@ZIF-8 catalysts were prepared by encapsulating Pd nanocubes within ZIF-8 for olefin hydrogenation, and the catalysts exhibited efficient performance in selective hydrogenation.…”