A New Porphyrin-based Covalent Organic Framework with High Iodine Capture Capacity and I-doping Enhanced Conductivity.

Covalent organic frameworks (COFs) are porous organic materials with well-defined and uniform structure. The material is an excellent candidate as a solid adsorbent for iodine adsorption. In the present study, we report the synthesis of COF with porphyrin moiety, TF-TA-COF, by solvothermal reaction, which was characterized by XRD, solid-state 13 C NMR, IR, TGA, and nitrogen adsorption-desorption analysis. TF-TA-COF showed a high specific surface area of 443 m2 g-1 , and exhibited good adsorption performance for iodine vapor, with an adsorption capacity of 2.74 g g-1 . XPS and Raman spectrum indicated that a hybrid of physisorption and chemisorption took place between host COF and iodine molecules. The electric properties of iodine-loaded TF-TA-COF were also studied. After doped with iodine, the conductivity of the material increased by more than 5 orders of magnitude. The photoconductivity of I2 -doped COF was also studied and TF-TA-COF showed doping-enhanced photocurrent generation.

Anionic Chemistry Modulation Enabled Environmental Self-Charging Aqueous Zinc Batteries: The Case of Carbonate Ions.

Anionic chemistry modulation represents a promising avenue to enhance the electrochemical performance and unlock versatile applications in cutting-edge energy storage devices. Herein, we propose a methodology that involves anionic chemistry of carbonate anions to tailor the electrochemical oxidation-reduction reactions of bismuth (Bi) electrodes, where the conversion energy barrier for Bi (0) to Bi (III) has been significantly reduced, endowing anionic full batteries with enhanced electrochemical kinetics and chemical self-charging property. The elaborately designed batteries with an air-switch demonstrate rapid self-recharging capabilities, recovering over 80% of the electrochemical full charging capacity within a remarkably short timeframe of 1 hour and achieving a cumulative self-charging capacity of 5 Ah g-1. The aqueous self-charging battery strategy induced by carbonate anion, as proposed in this study, holds the potential for extending to various anionic systems, including seawater-based Cl- ion batteries. This work offers a universal framework for advancing next-generation multi-functional power sources.

Biodegradable Hollow-Structured Nanozymes Modulate Phenotypic Polarization of Macrophages and Relieve Hypoxia for Treatment of Osteoarthritis.

Nanozymes are widely applied for treating various major diseases, including neurological diseases and tumors. However, the biodegradability of nanozymes remains a great challenge, which hinders their further clinical translation. Based on the microenvironment of osteoarthritis (OA), a representative pH-responsive biodegradable hollow-structured manganese Prussian blue nanozyme (HMPBzyme) is designed and applied for treatment of OA. HMPBzyme with good pH-responsive biodegradability, biocompatibility, and multi-enzyme activities is constructed by bovine serum albumin bubbles as a template-mediated biomineralization strategy. HMPBzyme suppresses hypoxia-inducible factor-1α (HIF-1α) expression and decreases reactive oxygen species (ROS) level in the in vitro experiment. Furthermore, HMPBzyme markedly suppresses the expression of ROS and alleviates the degeneration of cartilage in OA rat models. The results indicate that the biodegradable HMPBzyme inhibits oxidative damage and relieves hypoxia synergistically to suppress inflammation and promote the anabolism of cartilage extracellular matrix by protecting mitochondrial function and down-regulating the expression of HIF-1α, which modulates the phenotypic conversion of macrophages from pro-inflammatory M1 subtype to anti-inflammatory M2 subtype for OA treatment. This research lays a solid foundation for the design, construction, and biomedical application of biodegradable nanozymes and promotes the application of nanozymes in biomedicine.

[Analysis of the stress state in articular cartilage defect repairing area].

Based on transversely isotropic theory, a finite element model for three-dimensional solid-liquid coupling defect repair of articular cartilage was established. By studying stress state of host cartilage near the restoration interface, we identified deformation type of cartilage and discussed the cause of restoration interface cracking. The results showed that the host cartilage surface node near the restoration interface underwent compression deformation in the condition of surface layer defect repair. When the middle layer, deep layer or full-thickness defect were repaired, the node underwent tensile deformation. At this point, the radial dimension of cartilage increased, which might cause restoration interface cracking. If elastic modulus of the tissue engineered cartilage (TEC) was lower (0.1 MPa, 0.3 MPa), the host cartilage surface layer and middle layer mainly underwent tensile deformation. While elastic modulus of TEC was higher (0.6 MPa, 0.9 MPa), each layer of host cartilage underwent compression deformation. Therefore, the elastic modulus of TEC could be increased properly for full-thickness defect repair. This article provides a new idea for evaluating the effect of cartilage tissue engineering repair, and has a certain guiding significance for clinical practice.

Flame Retardancy of Epoxy Resins Modified with Few-Layer Black Phosphorus.

Few-layer black phosphorus (BP)- and red phosphorus (RP)-modified diglycidyl ether of bisphenol A-based epoxy resins (EP) was prepared with 4,4'-diaminodiphenylsulfone as a curing agent. The thermal stability and flame-retardant properties of the modified EPs were compared. Both BP and RP were able to improve the flame-retardant properties of EPs, while the BP showed higher flame-retardant efficiency than RP. As a two-dimensional nanomaterial, BP exhibited good compatibility, high flame-retardant efficiency, and negligible impact on the mechanical and thermal stability of EP. Pyrolysis-gas Fourier-transform infrared spectroscopic analysis of EP showed that the addition of BP significantly inhibited the release of pyrolysis products in the gas phase. The modes of action for flame-retardant BPs in gas phase and condensed phase were proposed.

Prussian Blue Nanozyme Normalizes Microenvironment to Delay Osteoporosis.

Osteoporosis (OP) is the most common orthopedic disease in the elderly and the main cause of age-related mortality and disability. However, no satisfactory intervention is currently available in clinical practice. Thus, an effective therapy to prevent or delay the development of OP should be devised. Osteoclastogenesis overactivation and excessive bone resorption are the main characteristics of OP. Accordingly, a paradigm for nanozyme-mediated normalization of the disease microenvironment to regulate osteoclast differentiation and delay OP is proposed. Hollow Prussian blue nanozymes (HPBZs) are prepared via template-free hydrothermal synthesis and selected as representative nanozymes. The intrinsic osteoclast activity-remodeling bioactivities of the HPBZs are explored in vitro and in vivo, focusing on their impact on osteogenesis and specific molecular mechanisms using an OP murine model. The HPBZs significantly normalize the OP microenvironment, thereby inhibiting osteoclast formation and osteoclast resorption, possibly owing to the suppression of intracellular reactive oxygen species generation, the mitogen-activated protein kinase, and nuclear factor κB signaling pathways. Consistently, in an ovariectomy-induced OP murine model, HPBZ treatment significantly attenuates osteoporotic bone loss in vivo. The findings confirm the HPBZ-mediated normalization of the disease microenvironment for the treatment of OP and suggest its application to other inflammation-related diseases.