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Multi‐component deoxyribozymes (MNAzymes) have shown extraordinary potential in precise gene therapy in vitro, however, the in vivo application is limited by complicated delivery systems. Herein, a novel DNA‐metal binding mechanism is discovered, and metal‐nucleic acid frameworks (MNFs) are built composed of MNAzymes and metal ions, which enable the carrier‐free self‐delivery of MNAzymes. Metal ions have a high affinity to DNA, however, the binding of metals with DNA at 20–30 base pair long (that normally a MNAzyme has) to form MNF structure is challenged by stringent high‐temperature synthesis conditions, poor stability of the products, and lack of targeting capabilities. While, it is discovered that through folding and entanglement of the MNAzyme with an aptamer tail, and prolonging the sequence to 71 base pair, the metal MNAzymes binding is significantly improved and stabilized to MNF structure even at room temperature. Moreover, the aptamer tail also endows MNFs with targeting capabilities. As proof of concept, a carrier‐free Ca/MNAzyme delivery system at room temperature, loaded with the model imaging protein BSA‐Cy5 is synthesized. This system can effectively target Her‐2 positive gastric cancer cells with the Her‐2 responsive aptamer tail and initiate dual gene regulation, thereby inducing energy depletion in cancer cells. [ABSTRACT FROM AUTHOR]

Bioartificial livers have showcased significant value in the treatment of acute liver failure (ALF). Current efforts are directed toward overcoming challenges in the development of microcarriers, with a specific emphasis on integrating higher‐density liver cells to enhance detoxification capabilities. Here, inspired by the radial filtration model in hepatic lobules, ion‐specific silk fibroin microcarriers are proposed with biomimetic niches for cultivating functional liver cells at high density. These biomimetic microcarriers are generated by capillary microfluidic device with controllable adjustments of ion type or concentration within the aqueous phase. When cultivating human induced pluripotent stem cell ‐differentiated mature liver cells on these recrystallized microcarriers, notably enhanced cell proliferation activity, as well as increased metabolic and secretory functionality is observed. Based on these features, the microcarrier‐integrated bioreactor can effectively reduce hepatic transaminase levels and significantly improve urea, albumin production, and survival rate in rabbit ALF models is demonstrated. Thus, it is believed that the biomimetic microcarriers and their derived bioreactor may hold potential for clinical applications in managing ALF and other liver diseases. [ABSTRACT FROM AUTHOR]

Diabetic wound healing is a serious, complex, and chronic process; one current promising and focusing technology in this area is stem cell treatment. Here, novel porous microneedle (MN) arrays is fabricated, which can highly mimetic stem cell niches, through template filling, and particle etching method. The human adipose‐derived stem cells (ADSCs) are encapsulated in Matrigel then loaded into the porous MN arrays by post‐perfusion. Because of the extracellular matrix‐mimicking, the biocompatible Matrigel offers a bionic microenvironment of stem cell nest suitable for growth. Benefiting from the numerous pore structures of MNs, the loaded ADSCs have enough space to fully absorb nutrients, proliferate greatly and exhibit prompted function. In addition, the cell‐loaded MN arrays have enough mechanical strength to penetrate the skin, allowing the ADSCs to get into the deep wound areas. Based on these features, the performance of the resultant MN arrays in promoting tissue regeneration is demonstrated, collagen deposition and angiogenesis in diabetes wounds of rat models. Thus, it is believe that the bioinspired porous MNs can act as excellent stem cell scaffolds and will find many practical values in clinic wound healing. [ABSTRACT FROM AUTHOR]

Recent experiments have demonstrated an extremely high output voltage of 260 V by impinging droplets on an electret surface with top and back electrodes. However, the mechanism underlying the generated high voltage remains elusive. Through high‐speed imaging of the impinging water droplet, it is found that the recorded voltage is proportional to the change rate of contact length l between the droplet and the top electrode over time, that is, dl/dt. By combining an electrostatic model with multi‐physics simulations, the time‐dependent charge distribution on the top electrode is analytically described as a function of several key factors pertaining to the spreading dynamics of droplet and the geometrical dimensions of device. These results show that the high voltage originates from the accumulation of charge in the spreading droplet and the ensuing instantaneous discharge upon high‐speed contact with the top electrode. Using the model‐optimized parameters, the experimentally generated voltage from a falling 64 µL droplet with a 2 mm salt can be boosted to 1030 V, giving rise to an energy conversion efficiency as high as 3.3%. This conversion efficiency will further increase by 14 times if the surface charge density of the electret can be enhanced to its limit using state‐of‐the‐art fabrication techniques. [ABSTRACT FROM AUTHOR]

Bulk 1T‐TaSe2 as a charge‐density‐wave (CDW) conductor is of special interest for CDW‐based nanodevice applications because of its high CDW transition temperature. Reduced dimensionality of the strongly correlated material is expected to result in significantly different collective properties. However, the growth of atomically thin 1T‐TaSe2 crystals remains elusive, thus hampering studies of dimensionality effects on the CDW of the material. Herein, chemical vapor deposition (CVD) of atomically thin TaSe2 crystals is reported with controlled 1T phase. Scanning transmission electron microscopy suggests the high crystallinity and the formation of CDW superlattice in the ultrathin 1T‐TaSe2 crystals. The commensurate–incommensurate CDW transition temperature of the grown 1T‐TaSe2 increases with decreasing film thickness and reaches a value of 570 K in a 3 nm thick layer, which is 97 K higher than that of previously reported bulk 1T‐TaSe2. This work enables the exploration of collective phenomena of 1T‐TaSe2 in the 2D limit, as well as offers the possibility of utilizing the high‐temperature CDW films in ultrathin phase‐change devices. [ABSTRACT FROM AUTHOR]

Distal necrosis of random skin flap is always clinical problematic in plastic surgery. The development of 3D functional vascular networks is fundamental for the survival of a local random skin flap. Herein, an effective technique on constructing 3D fibrous scaffolds for accelerated vascularization is demonstrated using a photocrosslinkable natural hydrogel based on gelatin methacryloyl (GelMA) by electrospinning. It is found that the ultraviolet (UV) photocrosslinkable gelatin electrospun hydrogel fibrous membranes exhibit soft adjustable mechanical properties and controllable degradation properties. Furthermore, it is observed that the optimized hydrogel scaffolds can support endothelial cells and dermal fibroblasts adhesion, proliferation, and migration into the scaffolds, which facilitates vascularization. Importantly, a rapid formation of tubes is observed after 3 d seeding of endothelial cells. After GelMA fibrous scaffold implantation below the skin flap in a rat model, it is found that the flap survival rate is higher than the control group, and there is more microvascular formation, which is potentially beneficial for the flap tissue vascularization. These data suggest that GelMA hydrogels can be used for biomedical applications that require the formation of microvascular networks, including the development of complex engineered tissues. [ABSTRACT FROM AUTHOR]

A major bottleneck in nanometer-scale drug delivery systems is the fabrication of nanocarriers with excellent stability under physiological conditions that can both efficiently encapsulate therapeutic agents and controllably release their payloads. Herein, the formation of a novel nanocomposite based on the encapsulation of thermally hydrocarbonized porous silicon (THCPSi) nanoparticles with solid lipid nanoparticles (SLNs) on a 1:1 ratio is described. The THCPSi-SL nanocomposites (THCPSi-SLNCs) are formed using a solid-in-oil-in-water emulsion solvent evaporation method. TEM and FTIR analyses prove that THCPSi nanoparticles are successfully encapsulated in the SLN matrix. The formation of the THCPSi-SLNCs alters the surface smoothness and hydrophobicity of the THCPSi nanoparticles, and also remarkably enhances their stability in human plasma. After encapsulation, the cytocompatibility of the THCPSi nanoparticles with intestinal, liver, and macrophage cancer cells is also greatly improved. A prolonged release of the model drug, furosemide, from THCPSi-SLNC is achieved, indicating that the SLN matrix successfully seals the pores of the THCPSi nanoparticles. Flow cytometry and confocal fluorescence microscopy studies demonstrates the significantly reduced cellular association of THCPSi-SLNCs with the cells comparing to bare THCPSi nanoparticles. Overall, the THCPSi-SLNCs exhibits superior suspensibility and better stability against aggregation in aqueous buffer solutions, increases the particle surface smoothness and cytocompatibility, reduces the cellular association, increases the in vitro stability in human plasma, and prolonges the drug release. These results suggest that the nanocomposite is a promising nanovector system for drug delivery applications. [ABSTRACT FROM AUTHOR]

Osteoarthritis has been regarded as a typical lubrication deficiency related joint disease, which is characterized by the breakdown of articular cartilage at the joint surface and the inflammation of the joint capsule. Here, inspired by the structure of the fresh euryale ferox seed that possesses a slippery aril and a hard coat containing starchy kernel, a novel superlubricated nanoparticle, namely poly (3‐sulfopropyl methacrylate potassium salt)‐grafted mesoporous silica nanoparticles (MSNs‐NH2@PSPMK), is biomimicked and synthesized via a one‐step photopolymerization method. The nanoparticles are endowed with enhanced lubrication by the grafted PSPMK polyelectrolyte polymer due to the formation of tenacious hydration layers surrounding the negative charges, and simultaneously are featured with effective drug loading and release behavior as a result of the sufficient mesoporous channels in the MSNs. When encapsulated with an anti‐inflammatory drug diclofenac sodium (DS), the lubrication capability of the superlubricated nanoparticles is improved, while the drug release rate is sustained by increasing the thickness of PSPMK layer, which is simply achieved via adjustment of the precursor monomer concentration in the photopolymerization process. Additionally, the in vitro and in vivo experimental results show that the DS‐loaded MSNs‐NH2@PSPMK nanoparticles effectively protect the chondrocytes from degeneration, and thus, inhibit the development of osteoarthritis. Bioinspired by the unique structure of the fresh euryale ferox seed, a novel superlubricated drug‐loaded nanoparticle is designed and synthesized based on photopolymerization for the treatment of osteoarthritis. [ABSTRACT FROM AUTHOR]