Large size bone defects typically need a long recovery period of more than three months, while a rapid repair of large bone defects is of great important and presents a significant challenge in clinical. Osteoinduction and osteoconduction provide different pathways and biofunctions for bone repair. Here, a biomimetic bone spatial architecture scaffold loaded with drug were constructed for satisfied both of these two bone repair biofunctions. Contacted with the host bone tissue, the HAp scaffold facilitates osteoconduction mainly through the outer layer of the scaffold. Meanwhile, GelMA loaded drugs primarily facilitates osteoinduction in the inner layer of the scaffold by establishing an osteogenic microenvironment. In vitro cell experiments confirmed that HAp/GelMA/IC showed excellent biocompatibility and osteogenic differentiation. An animal model of rabbit femoral condyle defect confirmed that HAp/GelMA/IC promoted osteoinduction and osteoconduction biofunctions. This dual biofunctions design provided a promising strategy for fast bone reconstruction in the large size bone defects repair. Graphical abstract Download : Download high-res image (307KB) Download : Download full-size image
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The direct conversion of heat and electric energy through thermoelectric effects is one of the effective ways to improve energy efficiency and reduce carbon emission. Thermoelectric parameters are the basis to evaluate the thermoelectric conversion efficiency of thermoelectric materials. However, the measurement of thermoelectric properties in micro/nano thermoelectric materials is extremely difficult at a small scale. Accurate and rapid characterization of thermoelectric parameters is the foundation and key of the optimization design and application of thermoelectric materials. The small-scale and micro-nano structure of materials cannot only effectively change its thermal conductivity, but also affect its electrical conductivity and Seebeck coefficient, thus significantly improving the thermoelectric conversion efficiency. Therefore, it is urgent to study the coupling mechanism between micro-/nano- scale structure regulation and thermoelectric conversion. In this work, an in-situ characterization technique is proposed for the integration of structural regulation and thermoelectric properties of micro/nano materials, and the coupling mechanism is also investigated experimentally. The micro-nano structure of materials is controlled by micro-machining method to realize the adjustable and controllable conversion efficiency. The results demonstrated that structural regulation could effectively improve the ZT value with a maximum improvement of nearly 7 times, which indicated that it was an effective approach to improve the thermoelectric performance. Graphical abstract Download : Download high-res image (188KB) Download : Download full-size image
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Dielectric ceramic capacitors play a crucial role in energy electricity and electronic circuit systems owing to their exceptional ability to rapidly store and release electrical charge and remarkable power density. However, they still face critical challenges related to improving recoverable energy storage density (Wrec) and efficiency (η) synergistically. To address these issues, a novel relaxor ceramic system is designed in this work by introducing linear dielectric SrTiO3 (ST) into ferroelectric Bi0.5K0.5TiO3-BiFeO3 (BKT-BF) with large polarization. XRD refinement and TEM characterization demonstrate the coexistence of Rhombohedral (R3mr), Tetragonal (P4mm) and Cubic (Pm-3m) phases, which induces polar nano-regions (PNRs) in the ceramic and gives rise a decreased remanent polarization (Pr) and an enhanced η. SEM and ultraviolet–visible spectrum confirm a decreased grain size and a widened bandgap, leading to an ultra-high breakdown electric field. Therefore, a superior recoverable Wrec of 7.32 J/cm3 and an impressive η of 88.06% are achieved, accompanied by prominent stability across a wide temperature range (30-150 ℃), various frequencies (1-500 Hz), and a substantial number of cycles (1-105 cycles) in the BKT-BF-0.4ST sample. These findings strongly suggest that the BKT-BF-xST ceramic system holds exceptional promise for applications in pulse power capacitor applications. Graphical abstract Download : Download high-res image (244KB) Download : Download full-size image
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Mo2P as a new member of the advancing two-dimensional (2D) materials family has been theoretically identified in this study. We conducted extensive density functional theory calculations to explore the crystal structure, dynamical stability, mechanical response, electronic structure and optical properties. Mo2P was found to be metallic with the Fermi energy locating at the d bands of transition metal Mo. A high reflectivity of ∼100% at low energies less than 1 eV was observed, introducing Mo2P as a potential candidate for photonic and optoelectronic applications such as transmitting electromagnetic waves devices. Our calculations confirm that the novel 2D structure is dynamically stable and can withstand at high temperatures including 1000 K. Mo2P was found to yield high tensile strength and elastic modulus of 12 GPa nm and 56 GPa nm, respectively. We particularly evaluated the application of Mo2P as an anode material for Li and Na-ion rechargeable batteries. The open-circuit voltages of 0.88–1.06 V and 0.94–0.09 V were predicted for Li and Na ions storages, respectively, which are desirable for commercial anodic materials. Interestingly, our calculations predict remarkably low diffusion energy barriers of 50 meV and 17 meV for Li and Na adatoms, respectively, promising to achieve ultrafast charging/discharging. The findings provided by this study can motivate further experimental and theoretical studies to probe new 2D crystals made from phosphor and transition metals with 2H and 1T atomic structures. Graphical abstract Download : Download high-res image (152KB) Download : Download full-size image
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Colorless polyimides (CPIs) with outstanding mechanical properties are used as essential materials in the production of future flexible display panels, foldable windows, and spacecraft cockpit materials. However, under repetitive stress and deformation, fatigue fractures caused by cracks and radio waves may act as critical determinants of the properties and duration of the material. To solve this problem, the present study developed a CPI capable of self-healing, wherein the transparency and any damage caused by external stress are rapidly and easily restored. Our synthesized CPI films showed ultra-transmittance (> 95%) and excellent self-healing efficiency (> 98%) with a simultaneously induced multi exchange network. Notably, the films exhibited excellent mechanical properties even after a bending fatigue test involving more than 10,000 cycles. This study therefore suggests a new type of CPI with a self-healing function and shows that the trade-off between the durability and functionality can be completely resolved. Graphical abstract Download : Download high-res image (225KB) Download : Download full-size image
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To circumvent the severe cytotoxicity and drug resistance of chemotherapeutics in cancer chemotherapy, we rationally designed an electrospun nanofibrous delivery system for the codelivery of the doxorubicin (DOX) and small interfering ribonucleic acid (siRNA) to improve antitumor activity and mitigate DOX drug resistance. DOX was intercalated into nanolamellar hydroxyapatite (LHAp), which was incorporated into electrospun poly(lactic-co-glycolic acid) (PLGA) nanofibers, and finally, the DOX-intercalated LHAp/PLGA scaffold was coated with polydopamine (PDA) followed by immobilization with siRNA/polyethyleneimine (PEI) complexes. Benefiting from its intrinsic degradability, the scaffold demonstrated pH-responsive release behavior, leading to the simultaneous delivery of DOX and siRNA. Consequently, the codelivery scaffold demonstrated enhanced therapeutic efficiency in vitro and in vivo compared with the scaffold loaded with single drug due to the combined effects of DOX and siRNA and did not show toxicity or side effects in mice. Therefore, it is a safe and effective strategy for preventing postsurgical tumor recurrence. Graphical abstract Download : Download high-res image (499KB) Download : Download full-size image
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Highlights • The biogenesis, composition, isolation techniques and potential therapeutic mechanisms of EVs are reviewed and discussed. • A summary of the engineering strategies for EVs is provided, along with an application of each strategy. • The recent advances in the application of EVs in tissue regeneration are summarized. • The challenges and development direction of EVs are introduced and discussed. Extracellular vesicles (EVs) are biologically active nanoparticles secreted by cells, which have a variety of physiological functions, such as promoting cell proliferation, regulating immunity, anti-inflammation, and facilitating angiogenesis. However, the application of EVs is limited by defects such as low therapeutic efficiency, lack of targeting, and unstable therapeutic effects. In recent years, various engineering methods have been developed to enhance the function of EVs. In addition, the research on the isolation methods and mechanisms of EVs has also made significant progress. In this paper, we review the biogenesis, composition, and isolation techniques of EVs, summarize the potential therapeutic mechanisms of natural EVs as well as the engineering strategies for EV modification, and highlight the recent advances in the application of EVs in tissue regeneration. Finally, we discuss EVs` current problems and future perspectives in regenerative medicine. Graphical abstract Download : Download high-res image (219KB) Download : Download full-size image
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Highlights • A convenient method for producing porous carbons with dual heteroatoms was reported. • Porous structure and heteroatom work synergistically to enhance catalytic activity. • Exceptional stability is shown by sustained high catalytic performance after 1-year storage. Development of affordable, efficient and metal-free heterogeneous catalytic systems has been a persistent challenge in academia and industry. Heteroatom-doped metal-free carbon materials are increasingly recognized as valuable heterogeneous catalysts, and if well-designed, can present comparable performance to, or even surpass transition metal-containing catalysts. Their physicochemical properties and structural characteristics are tunable in a wide range, plus being free of leakage problems of transition metal species into the environment. Herein, three types of hierarchically porous N/X co-doped carbon materials (X denotes B, P or S) were synthesized via using poly(ionic liquid)s (PILs) as carbon precursors and source of heteroatom dopants. The incorporation of sacrificial pore-inducing templating agents which created abundant edge defects, in combination with a heteroatom co-doping strategy, enhanced the number of active sites and their peroxidase-like catalytic activities. Comparison with only nitrogen single-doped porous carbons as reference demonstrated that co-doping with nitrogen and another heteroatom exhibits higher peroxidase-like activity and affinity towards substrates. Among the three types of heteroatom co-doped porous carbonaceous artificial enzymes, the N/B co-doped carbonaceous catalyst displayed the highest specific activities and Vmax values. These observations suggest a synergistic effect of the co-dopants, here N and B in the enzyme that holds a promising potential to further enhance peroxidase-like activity. Graphical abstract Download : Download high-res image (196KB) Download : Download full-size image
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Tumor surgery poses significant challenges, including the presence of residual tumors, bacterial infections, and tissue defects, which contribute to high rates of tumor recurrence, low survival rates, and impaired wound healing. To address these issues, hydrogels, three-dimensional network structures formed through the crosslinking of natural or synthetic macromolecules, have emerged as promising solutions. By leveraging nanostructure-loaded hydrogels, different therapeutic modalities can be integrated into a single platform and significantly enhance antitumor effects and inhibit postoperative tumor metastasis and recurrence through synergistic therapeutic approaches. Furthermore, by incorporating therapeutic drugs and bioactive matrices, these nanostructure-loaded hydrogels can provide long-lasting antimicrobial and anti-inflammatory effects while also facilitating the regeneration of bones, skin, and adipose tissue. This comprehensive review aims to explore the design strategies, latest advancements in research, and therapeutic applications of nanostructure-loaded hydrogels in the integrated fields of antitumor therapy and tissue regeneration, including their use in photothermal/photodynamic therapy, chemodynamic therapy, chemotherapy, enhanced radiotherapy, and magnetic hyperthermia, as well as the synergistic therapeutic applications of the above methods. Finally, the challenges and potential solutions of nanostructure-loaded hydrogels in clinical therapy are also proposed. Graphical abstract Download : Download high-res image (159KB) Download : Download full-size image
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