Chao Wei,Ji Tan,Shun Xing,Hongqin Zhu,Naijian Ge,Haifeng Zhang,Xuanyong Liu
Interventional therapy represents the primary treatment modality for cardiovascular disease associated with vascular obstruction. However, conventional stents are susceptible to thrombosis and infection, leading to serious threats to patient health and, in some cases, mortality. In this study, a Ta/Ta 2 O 5 /Ni 3 N film was prepared in situ on the nitinol (Ni-Ti) stent using a sequential plasma immersion ion implantation method. As tantalum has a negative charge under physiological conditions and nickel nitride adsorbs protons in solution, the introduction of tantalum and nickel nitride is expected to allow the surface charge of the material to be tailor-made. The film displays excellent hemocompatibility and reduced platelet adhesion, based on the combined effect of “mosaic-like” charge distribution of the film and the high dispersion/polarity component ratio in the surface tension. Ammonia species is an important physiological signaling molecule, which could be produced by the affinity of nitrogen in nickel nitride with protons in solution. In turn, ammonia species modulates the cellular NRF2/HO-1 signaling pathway, thereby enhancing cell viability. Furthermore, ammonia species increases intracellular eNOS gene expression, which enhances cell migration and promotes early endothelialization. Additionally, the depletion of protons by nickel nitride can disrupt bacterial metabolism, which results in the production of reactive oxygen species (ROS) and nitric oxide (NO) within the bacteria, achieving a killing efficacy of over 99.9% for both gram-negative Escherichia coli and gram-positive Staphylococcus aureus . It is anticipated that this straightforward, multifaceted inorganic bioactive film approach will prove an invaluable solution for enhancing the reliability of stents and reducing the burden on patients.
Currently, many cancer patients with bone defects are still threatened by tumor recurrence, postoperative bacterial infection, and massive bone loss. Many methods have been studied to endow bone implants with biocompatibility, but it is difficult to find an implant material that can simultaneously solve the problems of anticancer, antibacterial and bone promotion. Here, a multifunctional gelatin methacrylate/dopamine methacrylate adhesive hydrogel coating containing 2D black phosphorus (BP) nanoparticle protected by polydopamine (pBP) is prepared by photocrosslinking to modify the surface of poly (aryl ether nitrile ketone) containing phthalazinone (PPENK) implant. The multifunctional hydrogel coating works in conjunction with pBP, which can deliver drug through photothermal mediation and kill bacteria through photodynamic therapy at the initial phase followed by promotion of osteointegration. In this design, photothermal effect of pBP control the release of doxorubicin hydrochloride loaded via electrostatic attraction. Meanwhile, pBP can generate reactive oxygen species (ROS) to eliminate bacterial infection under 808 nm laser. In the slow degradation process, pBP not only effectively consumes excess ROS and avoid apoptosis induced by ROS in normal cells, but also degrade into PO 4 3− to promote osteogenesis. In summary, nanocomposite hydrogel coatings provide a promising strategy for treatment of cancer patients with bone defects.
Yuehua Xu,Yan Fang,Yanjing Ou,Liyu Yan,Qinhui Chen,Caixia Sun,Jiang Chen,Haiqing Liu
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 m2·g–1) and super-hydrophilicity, 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 Zn2+ 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.
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