Multicomponent deoxyribozymes (MNAzymes) have great potential in gene therapy, but their ability to recognize disease tissue and further achieve synergistic gene regulation has rarely been studied. ...Herein, Arginylglycylaspartic acid (RGD)-modified Distearyl acylphosphatidyl ethanolamine (DSPE)-polyethylene glycol (PEG) (DSPE-PEG-RGD) micelle is prepared with a DSPE hydrophobic core to load the photothermal therapy (PTT) dye IR780 and the calcium efflux pump inhibitor curcumin. Then, the MNAzyme is distributed into the hydrophilic PEG layer and sealed with calcium phosphate through biomineralization. Moreover, RGD is attached to the outer tail of PEG for tumor targeting. The constructed nanomachine can release MNAzyme and the cofactor Ca
under acidic conditions and self-assemble into an active mode to cleave heat shock protein (HSP) mRNA by consuming the oncogene miRNA-21. Silencing miRNA-21 enhances the expression of the tumor suppressor gene PTEN, leading to PTT sensitization. Meanwhile, curcumin maintains high intracellular Ca
to further suppress HSP-chaperone ATP by disrupting mitochondrial Ca
homeostasis. Therefore, pancreatic cancer is triple-sensitized to IR780-mediated PTT. The in vitro and in vivo results show that the MNAzyme-based nanomachine can strongly regulate HSP and PTEN expression and lead to significant pancreatic tumor inhibition under laser irradiation.
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•Hollow N/Co codoped carbon spheres are successfully prepared.•PS@bimetal-ZIFs are synthesized and used as the sacrifice templates.•The structure properties of Co-HNCS can be well ...regulated.•The optimal catalyst is a promising candidate for oxygen reduction reaction.
To explore efficient non-noble metal-based electrocatalysts for oxygen reduction reaction (ORR), herein we developed a facile bottom-up approach for the fabrication of a hollow porous carbon sphere codoped with ultra-small Co nanoparticles and uniform nitrogen distribution (Co-HNCS) via one-step pyrolysis of a core-shell type precursor composing of polystyrene (PS) core and bimetallic ZIF (zeolite imidazolate framework) shell. The bimetallic Co-Zn-ZIFs (BMZIFs) was selected as the sacrifice template due to not only its high nitrogen content and regular porosity but also the superiority that Zn species in BMZIFs can both spatially separate Co species to suppress the aggregation of ultra-small Co NPs and be evaporated to afford extra pores during high-temperature pyrolysis. As expected, by adjusting the starting molar ratio of Zn to Co, we were able to prepare Co-HNCS-x (x represent the molar ratio of Co to total starting metal feeding) that exhibited unique hollow structure with large surface areas, enhanced mass transport, high porosities, tunable particle sizes and graphitization degrees, abundant highly active CoNx sites, and thus significantly improved ORR performance. Particularly, the optimal Co-HNCS-0.2 exhibited the remarkable ORR activity (the onset and half-wave potentials were 0.94 and 0.82Vvs. RHE, respectively) via an efficient four-electron-dominant ORR process in alkaline medium, which outperformed that of commercial Pt/C (20wt%, the onset and half-wave potentials were 0.93 and 0.80Vvs. RHE, respectively) and most of previously reported Co-based catalysts. Moreover, it also displayed much superior stability and tolerance to methanol as compared to Pt/C, further highlighting the merit of this facile synthesis approach. Our findings might inspire new thoughts on the development of precious-metal-free, highly-efficient and cost-effective ORR electrocatalysts derived from MOF.
Soft electronics that seamlessly interface with skin are of great interest in health monitoring and human–machine interfaces. However, achieving mechanical softness, skin adhesiveness, and high ...conductivity concurrently has always been a major challenge due to the difficulty in bonding dissimilar materials while retaining their respective properties. Herein, the mechanically interlocked hydrogel–elastomer hybrid is reported as a viable solution to this problem. Hydrogels with low moduli and high adhesiveness are employed as the substrate, while porous elastomer webs are used as matrices to load conductive films and lock the hydrogels through a mechanically interlocked structure. The bonding strength between the hydrogel and elastomer in the interlocking hybrid structure is 14.3 times of that obtained via the physical stacking method. As a proof of concept, interlocking hybrids are used as on‐skin electrodes for electrophysiological signal recording including electromyography and electrocardiography. The robust hybrid electrodes are able to detect signals after multiple cycles. The proposed strategy not only is an effective approach to achieve interlocking structures, but also provides a new perspective for soft and stretchable electronics.
A novel hydrogel–elastomer hybrid is developed by mechanical interlocking. Porous elastomer webs are used as matrices to load conductive materials and lock hydrogels through an interlocking structure to achieve mechanically soft and skin‐adhesive electrodes. The interlocking hybrid is used as an on‐skin electrode for recording electrophysiological signals.
Fiber‐shaped stretchable strain sensors with small testing areas can be directly woven into textiles. This paves the way for the design of integrated wearable devices capable of obtaining real‐time ...mechanical feedback for various applications. However, for a simple fiber that undergoes uniform strain distribution during deformation, it is still a big challenge to obtain high sensitivity. Herein, a new strategy, surface strain redistribution, is reported to significantly enhance the sensitivity of fiber‐shaped stretchable strain sensors. A new method of transient thermal curing is used to achieve the large‐scale fabrication of modified elastic microfibers with intrinsic microbeads. The proposed strategy is independent of the active materials utilized and can be universally applied for various active materials. The strategy used here will shift the vision of the sensitivity enhancement method from the active materials design to the mechanical design of the elastic substrate, and the proposed strategy can also be applied to nonfiber‐shaped stretchable strain sensors.
Surface strain redistribution in substrates significantly enhances sensitivity of fiber‐shaped stretchable strain sensors fabricated by thermal‐transient‐curing and Plateau–Rayleigh instability. Poly(dimethylsiloxane) (PDMS) microfibers with beads are produced in large scale. The beads regulate strain distribution. Novel sensors are well adhered to textiles for monitoring sports activities. This study opens up a new perspective of fiber‐shaped sensors and a method to enhance sensitivity.
Human behaviors are extremely sophisticated, relying on the adaptive, plastic and event-driven network of sensory neurons. Such neuronal system analyzes multiple sensory cues efficiently to establish ...accurate depiction of the environment. Here, we develop a bimodal artificial sensory neuron to implement the sensory fusion processes. Such a bimodal artificial sensory neuron collects optic and pressure information from the photodetector and pressure sensors respectively, transmits the bimodal information through an ionic cable, and integrates them into post-synaptic currents by a synaptic transistor. The sensory neuron can be excited in multiple levels by synchronizing the two sensory cues, which enables the manipulating of skeletal myotubes and a robotic hand. Furthermore, enhanced recognition capability achieved on fused visual/haptic cues is confirmed by simulation of a multi-transparency pattern recognition task. Our biomimetic design has the potential to advance technologies in cyborg and neuromorphic systems by endowing them with supramodal perceptual capabilities.
High‐energy Li‐rich layered cathode materials (≈900 Wh kg−1) suffer from severe capacity and voltage decay during cycling, which is associated with layered‐to‐spinel phase transition and oxygen redox ...reaction. Current efforts mainly focus on surface modification to suppress this unwanted structural transformation. However, the true challenge probably originates from the continuous oxygen release upon charging. Here, the usage of dielectric polarization in surface coating to suppress the oxygen evolution of Li‐rich material is reported, using Mg2TiO4 as a proof‐of‐concept material. The creation of a reverse electric field in surface layers effectively restrains the outward migration of bulk oxygen anions. Meanwhile, high oxygen‐affinity elements of Mg and Ti well stabilize the surface oxygen of Li‐rich material via enhancing the energy barrier for oxygen release reaction, verified by density functional theory simulation. Benefited from these, the modified Li‐rich electrode exhibits an impressive cyclability with a high capacity retention of ≈81% even after 700 cycles at 2 C (≈0.5 A g−1), far superior to ≈44% of the unmodified counterpart. In addition, Mg2TiO4 coating greatly mitigates the voltage decay of Li‐rich material with the degradation rate reduced by ≈65%. This work proposes new insights into manipulating surface chemistry of electrode materials to control oxygen activity for high‐energy‐density rechargeable batteries.
A dielectric inverse spinel‐structured Mg2TiO4 coating on Li‐rich cathode material significantly suppresses the continuous oxygen release, endowing batteries with remarkable cyclability and well‐inhibited voltage decay, e.g., showing a capacity retention of ≈81% and voltage degradation of only 151 mV after 700 cycles, far superior to 44% and 432 mV of the unmodified counterpart.
The first mechanically and electrically self‐healing supercapacitor has been successfully fabricated. It exhibits excellent self‐healing performance with the restoration of the specific capacitance ...up to 85.7% of its original value even after the 5th mechanical cutting. This achievement may provide a way to expand the lifetime of future energy storage devices and endow them with desirable economic and human safety attributes, as well as promote the development of next‐generation self‐healing electronics.
Urine for diagnostics: Urine, a “green” natural product, is used as an active component to produce a simple, inexpensive, and portable colorimetric Hg2+ sensing assay with high selectivity and ...sensitivity by simply mixing gold nanoparticles (AuNPs) and urine. The synergetic effect of uric acid and creatinine decorated on AuNPs is the reason for selective binding of Hg2+, leading to the aggregation of gold nanoparticles and thereby causing a visible color change.
Flexible electronic devices are necessary for applications involving unconventional interfaces, such as soft and curved biological systems, in which traditional silicon‐based electronics would ...confront a mechanical mismatch. Biological polymers offer new opportunities for flexible electronic devices by virtue of their biocompatibility, environmental benignity, and sustainability, as well as low cost. As an intriguing and abundant biomaterial, silk offers exquisite mechanical, optical, and electrical properties that are advantageous toward the development of next‐generation biocompatible electronic devices. The utilization of silk fibroin is emphasized as both passive and active components in flexible electronic devices. The employment of biocompatible and biosustainable silk materials revolutionizes state‐of‐the‐art electronic devices and systems that currently rely on conventional semiconductor technologies. Advances in silk‐based electronic devices would open new avenues for employing biomaterials in the design and integration of high‐performance biointegrated electronics for future applications in consumer electronics, computing technologies, and biomedical diagnosis, as well as human–machine interfaces.
Silk fibroin is an ancient biomaterial with exquisite mechanical, optical, and electrical properties. Its intriguing properties and environmental benignity render silk fibroin compelling for the advancement of next‐generation biocompatible and biodegradable flexible electronic devices.
Stretchable electronics are essential for the development of intensely packed collapsible and portable electronics, wearable electronics, epidermal and bioimplanted electronics, 3D surface compliable ...devices, bionics, prosthesis, and robotics. However, most stretchable devices are currently based on inorganic electronics, whose high cost of fabrication and limited processing area make it difficult to produce inexpensive, large‐area devices. Therefore, organic stretchable electronics are highly attractive due to many advantages over their inorganic counterparts, such as their light weight, flexibility, low cost and large‐area solution‐processing, the reproducible semiconductor resources, and the easy tuning of their properties via molecular tailoring. Among them, stretchable organic semiconductor devices have become a hot and fast‐growing research field, in which great advances have been made in recent years. These fantastic advances are summarized here, focusing on stretchable organic field‐effect transistors, light‐emitting devices, solar cells, and memory devices.
Stretchable organic semiconductor devices are essential for the development of low‐cost, large‐area collapsible and portable electronics, wearable electronics, epidermal and bioimplanted electronics, 3D surface compliable devices, bionics, prosthesis, and robotics. Great advances have been made in this field in recent years, which are summarized, focusing on stretchable organic field‐effect transistors, light‐emitting devices, solar cells, and memory devices.
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