Search

Vascularization and inflammation management are essential for successful bone regeneration during the healing process of large bone defects assisted by artificial implants/fillers. Therefore, this study is devoted to the optimization of the osteogenic microenvironment for accelerated bone healing through rapid neovascularization and appropriate inflammation inhibition that were achieved by applying a tantalum oxide (TaO)-based nanoplatform carrying functional substances at the bone defect. Specifically, TaO mesoporous nanospheres were first constructed and then modified by functionalized metal ions (Mg2+) with the following deferoxamine (DFO) loading to obtain the final product simplified as DFO-Mg-TaO. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that the product was homogeneously dispersed hollow nanospheres with large specific surface areas and mesoporous shells suitable for loading Mg2+and DFO. The biological assessments indicated that DFO-Mg-TaO could enhance the adhesion, proliferation, and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). The DFO released from DFO-Mg-TaO promoted angiogenetic activity by upregulating the expressions of hypoxia-inducible factor-1 (HIF-1α) and vascular endothelial growth factor (VEGF). Notably, DFO-Mg-TaO also displayed anti-inflammatory activity by reducing the expressions of pro-inflammatory factors, benefiting from the release of bioactive Mg2+. In vivoexperiments demonstrated that DFO-Mg-TaO integrated with vascular regenerative, anti-inflammatory, and osteogenic activities significantly accelerated the reconstruction of bone defects. Our findings suggest that the optimized DFO-Mg-TaO nanospheres are promising as multifunctional fillers to speed up the bone healing process.

Rechargeable Li–CO2batteries have been receiving intense interest because of their high theoretical energy density and environmentally friendly CO2fixation ability. However, due to the sluggish CO2reduction/evolution reaction (CRR/CER) kinetics, the current Li–CO2batteries still suffer from severe polarization and poor cycling stability. Herein, we designed and in situ synthesized sea urchinlike Mn2O3–Mn3O4nanocomposite and explored the synergistic effect between Mn2O3and Mn3O4during charge–discharge process in Li–CO2batteries. It is found that Mn3O4can effectively promote the kinetics of CRR process, and Mn2O3can induce the nucleation of Li2CO3and promote its decomposition (CER). Benefiting from the dual-phase synergy, the Mn2O3–Mn3O4cathode combines the respective catalytic advantages of the both and delivers a high full discharge capacity of 19 024 mAh g–1, a low potential gap of 1.24 V, and durable cycling stability (1380 h) at a current density of 100 mA g–1. Moreover, based on experimental results and density functional theory (DFT) calculations, a charge–discharge process model of the Mn2O3–Mn3O4cathode was established to display the electrochemical reaction mechanism. We hope that this design strategy can encourage further studies for efficient cathode catalysts to accelerate the practical application of Li–CO2batteries and even the metal–air batteries.

Silicon is considered to be one of the most important high-energy density anode materials for next-generation lithium-ion batteries. A large number of experimental studies on silicon anode have achieved better results, and greatly promoted its practical application potentiality, but almost of them are only tested in metal lithium half batteries. There is still an unavoidable question for commercial applications: what is the performance of the full cell composed of a silicon anode and a manganese-based material cathode? In this paper, the growing solid electrolyte interphase (SEI) and deposited manganese ions of the silicon anode’s surface of the spinel lithium manganese oxide LiMn2O4/silicon full cells are quantitatively studied during electrochemical cycling, and the SEI performances are tested by differential scanning calorimetry to find out the reason for the rapid decline of reversible capacity in the LiMn2O4/silicon system. The experimental results show that manganese ions can make SEI films rapidly grow on the silicon anode and make SEI films more brittle, which results in lower Coulombic efficiency and rapid decline in capacity of the silicon anode.

Leptin, a kind of adipokine, with its receptor in which the long isoform plays a crucial role in signal transduction, has been identified in intervertebral disc (IVD) tissues, especially showing an increased expression in degenerated discs. Initially identified as a metabolic sensor, leptin has recently been found able to regulate inflammation into imbalance, which favors catabolic degradative processes, thus contributing to progressive intervertebral disc degeneration (IDD). Therefore, efficiently inhibiting the leptin pathway may provide a new strategy to treat IDD. In this study, we introduced an innovative drug delivery system (DDS) that employs stem cell membranes (SCM) to encapsulate (Zeolitic imidazolate frameworks-8) ZIF-8 nanoparticles. These nanoparticles are used to transport a plasmid containing shRNA targeting the leptin receptor (LEPR), with the aim of facilitating repair in IDD. The regenerative performances of this DDS in IDD were verified through a combination of the in vitrowestern blot and immunofluorescence with the in vivoradiologic examination and histological staining. The DDS demonstrated excellent cell adhesion properties and gene transfection efficiency in vitro, along with impressive treatment outcomes in vivo. Both in vitroand in vivostudies revealed that the DDS effectively reduced leptin receptor expression and alleviated the inflammatory environment, thereby promoting regeneration in degenerated IVDs. We propose that the DDS represents a promising novel approach for treating IDD and may also be beneficial for other degenerative diseases linked to leptin pathway dysfunction.

Developing bone implants with dynamic self-adjustment of antibacterial, angiogenic, and osteogenic functions in line with a bone regenerative cascade is highly required in orthopedics. Herein, a unique core–shell nanorods array featuring a thin layer of NiS coated on each SrTiO3nanorod (NiS@SrTiO3) was in situ constructed on titanium (Ti) through a two-step hydrothermal treatment. Under near-infrared (NIR) irradiation, the photoresponsive effect of NiS layer in synergy with the physical perforation of SrTiO3nanorods initially enabled in vitro antibacterial rates of 96.5% to Escherichia coliand 93.1% to Staphylococcus aureus. With the degradation of the NiS layer, trace amounts of Ni ions were released, which accelerated angiogenesis by upregulating the expression of vascular regeneration-related factors, while the gradual exposure of SrTiO3nanorods could simultaneously enhance the surface hydrophilicity in favor of cell adhesion and slowly release Sr ions to promote the proliferation and differentiation of MC3T3-E1 cells. The in vivo assessment verified not only the satisfactory antibacterial effect but also the superior osteogenic ability of the NiS@SrTiO3/Ti group with the aid of NIR irradiation, finally promoting the osseointegration of the Ti implant. The modification method endowing Ti implant with antibacterial, angiogenic, and osteogenic functions provides a new strategy to improve the long-term reliability of Ti-based devices.

In practical implementation of TiO2semiconductors, utilization of their outstanding properties is mainly hindered by poor material quality and high operational costs. In this contribution, the electrospinning method was employed to fabricate N-doped mixed-crystalline TiO2with exposed high-energy facets. The Ti oxide transformation process was thoroughly studied. During the mixed crystal structure formation process, the high-energy facets could be preserved due to the lower calcination temperature and the protective role of polyvinylpyrrolidone (PVP) in the electrospinning process. In addition, after calcination, the N doping, generated by the decomposition of PVP, extended the absorption spectrum of TiO2to the visible region. These TiO2fibers exhibited superior photooxidation of arsenite (III) to arsenate (V)in both the UV and visible light regions, mainly attributed to the exposure of high-energy facets, robust separation of photoexcited charge carriers between the anatase/rutile phases, and narrow band gap induced by the in situ N doping. Combining both robustness and scalability, the TiO2fibers produced via this electrospinning process have the potential for a broad range of applications.