Current cancer therapy is seriously challenged by tumor metastasis and recurrence. One promising solution to these problems is to build antitumor immunity. However, immunotherapeutic efficacy is ...highly impeded by the immunosuppressive state of the tumors. Here a new strategy is presented, catalytic immunotherapy based on artificial enzymes. Cu2−xTe nanoparticles exhibit tunable enzyme‐mimicking activity (including glutathione oxidase and peroxidase) under near‐infrared‐II (NIR‐II) light. The cascade reactions catalyzed by the Cu2−xTe artificial enzyme gradually elevates intratumor oxidative stress to induce immunogenic cell death. Meanwhile, the continuously generated oxidative stress by the Cu2−xTe artificial enzyme reverses the immunosuppressive tumor microenvironment, and boosts antitumor immune responses to eradicate both primary and distant metastatic tumors. Moreover, immunological memory effect is successfully acquired after treatment with the Cu2−xTe artificial enzyme to suppress tumor relapse.
Stressed out: Cu2−xTe nanoparticles are presented as a new artificial multienzyme with enzymatic activity reinforced by near‐infrared‐II (NIR‐II) light. Cu2−xTe catalyzes cascade reactions continuously and elevates intratumor oxidative stress, which not only eradicates primary tumors, but also reverses the tumor immunosuppressive (cold) state into a proinflammatory (hot) state to combat tumor metastasis and recurrence.
Hydrogel electrolytes have spurred the development of flexible energy storage devices by endowing them with liquid‐like ion transport and solid‐like mechanical elasticity. However, traditional ...hydrogel electrolytes always lose these functions in climate change because the internal water undergoes freezing and/or dehydration. In this work, a flexible supercapacitor (OHEC) is assembled based on the organohydrogel electrolyte (OHE) and activated carbon electrode material. The OHE is composed of PAMPS/PAAm double‐network hydrogel soaked from 4 m LiCl/ethylene glycol and exhibits good conductivities (1.9 and 22.9 mS cm−1 at −20 and 25 °C, respectively). The OHEC exhibits broad temperature adaptability (from −20 to 80 °C) and extraordinary resistance to mechanical damage (above 100 kg crushing). The OHEC avoids the polarization at low temperatures and retains 77.8% capacitance retention after storage at −20 °C for 30 days. Without extra sealed packaging, the OHEC maintains remarkable cycling stability (only 8.7% capacitance decay after 10 000 cycles) and retains 77.3% capacitance at 80 °C after 56 h. The outstanding anti‐drying performance and improved interfacial compatibility of OHEC account for the good durability in the high‐temperature environments. Additionally, other salts (such as LiClO4, NaCl, and KCl) with favorable solubility in ethylene glycol can also serve in OHEs for wide temperature range supercapacitors.
A flexible organohydrogel electrolyte‐based supercapacitor (OHEC) is assembled with a PAMPS/PAAm double‐network organohydrogel and activated carbon. Compared to the hydrogel electrolyte‐based supercapacitor, the OHEC exhibits broad temperature adaptability (from −20 to 80 °C) due to the improvement of interfacial compatibility as well as the inhibition of electrochemical polarization and water evaporation.
A black phosphorus (BP)‐based drug delivery system for synergistic photodynamic/photothermal/chemotherapy of cancer is constructed. As a 2D nanosheet, BP shows super high drug loading capacity and ...pH‐/photoresponsive drug release. The intrinsic photothermal and photodynamic effects of BP enhance the antitumor activities. The synergistic photodynamic/photothermal/chemotherapy makes BP‐based drug delivery system a multifunctional nanomedicine platform.
Iron, nitrogen‐codoped carbon (Fe−N−C) nanocomposites have emerged as viable electrocatalysts for the oxygen reduction reaction (ORR) due to the formation of FeNxCy coordination moieties. In this ...study, results from first‐principles calculations show a nearly linear correlation of the energy barriers of key reaction steps with the Fe magnetic moment. Experimentally, when single Cu sites are incorporated into Fe−N−C aerogels (denoted as NCAG/Fe−Cu), the Fe centers exhibit a reduced magnetic moment and markedly enhanced ORR activity within a wide pH range of 0–14. With the NCAG/Fe−Cu nanocomposites used as the cathode catalyst in a neutral/quasi‐solid aluminum–air and alkaline/quasi‐solid zinc–air battery, both achieve a remarkable performance with an ultrahigh open‐circuit voltage of 2.00 and 1.51 V, large power density of 130 and 186 mW cm−2, and good mechanical flexibility, all markedly better than those with commercial Pt/C or Pt/C‐RuO2 catalysts at the cathode.
First‐principles calculations show a nearly linear correlation of the energy barriers of critical oxygen reduction reaction (ORR) steps with the Fe magnetic moment of Fe‐N‐C composites. This is indeed observed when single Cu sites are incorporated into Fe−N−C aerogels, where the interactions between adjacent Fe−Cu 3d electrons result in a reduced magnetic moment of the Fe center and hence enhanced ORR activity.
Piezoelectric materials, with their unique ability for mechanical‐electrical energy conversion, have been widely applied in important fields such as sensing, energy harvesting, wastewater treatment, ...and catalysis. In recent years, advances in material synthesis and engineering have provided new opportunities for the development of bio‐piezoelectric materials with excellent biocompatibility and piezoelectric performance. Bio‐piezoelectric materials have attracted interdisciplinary research interest due to recent insights on the impact of piezoelectricity on biological systems and their versatile biomedical applications. This review therefore introduces the development of bio‐piezoelectric platforms from a broad perspective and highlights their design and engineering strategies. State‐of‐the‐art biomedical applications in both biosensing and disease treatment will be systematically outlined. The relationships between the properties, structure, and biomedical performance of the bio‐piezoelectric materials are examined to provide a deep understanding of the working mechanisms in a physiological environment. Finally, the development trends and challenges are discussed, with the aim to provide new insights for the design and construction of future bio‐piezoelectric materials.
Bio‐piezoelectric platforms with the ability for mechanical–electrical energy conversion exhibit great potential in the biomedical field. The latest developments in bio‐piezoelectric platforms are introduced, their design and engineering strategies are highlighted, and the current state‐of‐the‐art in biomedical applications is systematically outlined. One closely combines the range of materials structures with their biomedical performance, aiming to provide insights for their design and construction in the future.
Transition‐metal dyshomeostasis is recognized as a critical pathogenic factor at the onset and progression of neurodegenerative disorder (ND). Excess transition‐metal ions such as Cu2+ can catalyze ...the generation of cytotoxic reactive oxygen species and thereafter induce neuronal cell apoptosis. Exploring new chelating agents, which are not only capable of capturing excess redox‐active metal, but can also cross the blood–brain barrier (BBB), are highly desired for ND therapy. Herein, it is demonstrated that 2D black phosphorus (BP) nanosheets can capture Cu2+ efficiently and selectively to protect neuronal cells from Cu2+‐induced neurotoxicity. Moreover, both in vitro and in vivo studies show that the BBB permeability of BP nanosheets is significantly improved under near‐infrared laser irradiation due to their strong photothermal effect, which overcomes the drawback of conventional chelating agents. Furthermore, the excellent biocompatibility and stability guarantee the biosafety of BP in future clinical applications. Therefore, these features make BP nanosheets have the great potential to work as an efficient neuroprotective nanodrug for ND therapy.
Black phosphorus (BP) nanosheets, having the capability of capturing Cu2+ efficiently and selectively, can not only act as an antioxidant to extenuate cellular oxidative stress and inhibit cell apoptosis, but also improve the blood–brain barrier permeability under near‐infrared laser irradiation through the photothermal effect. These properties of BP nanosheets make them an efficient neuroprotective nanodrug for neurodegenerative disorder therapy.
Fabrication of clinically translatable nanoparticles (NPs) as photothermal therapy (PTT) agents against cancer is becoming increasingly desirable, but still challenging, especially in facile and ...controllable synthesis of biocompatible NPs with high photothermal efficiency. A new strategy which uses protein as both a template and a sulfur provider is proposed for facile, cost‐effective, and large‐scale construction of biocompatible metal sulfide NPs with controlled structure and high photothermal efficiency. Upon mixing proteins and metal ions under alkaline conditions, the metal ions can be rapidly coordinated via a biuret‐reaction like process. In the presence of alkali, the inert disulfide bonds of S‐rich proteins can be activated to react with metal ions and generate metal sulfide NPs under gentle conditions. As a template, the protein can confine and regulate the nucleation and growth of the metal sulfide NPs within the protein formed cavities. Thus, the obtained metal sulfides such as Ag2S, Bi2S3, CdS, and CuS NPs are all with small size and coated with proteins, affording them biocompatible surfaces. As a model material, CuS NPs are evaluated as a PTT agent for cancer treatment. They exhibit high photothermal efficiency, high stability, water solubility, and good biocompatibility, making them an excellent PTT agent against tumors. This work paves a new avenue toward the synthesis of structure‐controlled and biocompatible metal sulfide NPs, which can find wide applications in biomedical fields.
Metal sulfide nanoparticles (NPs) with ultrasmall size, and good biocompatibility are facilely obtained via alkali‐driven transformation of S‐rich protein–metal complexes. Proteins work as both a sulfur resource and a template, where disulfide bonds are activated to react with metal ions and form metal sulfide NPs in situ, which are proved to be an excellent theranostic platform for cancer therapy.
Nanodrugs are becoming increasingly important in the treatment of bacterial infection, but their low penetration ability to bacterial biofilm is still the main challenge hindering their therapeutic ...effect. Herein, nitric oxide (NO)‐driven nanomotor based on L‐arginine (L‐Arg) and gold nanoparticles (AuNPs) loaded dendritic mesoporous silica nanoparticles (AG‐DMSNs) is fabricated. AG‐DMSNs have the characteristics of cascade catalytic reaction, where glucose is first catalyzed by the asymmetrically distributed AuNPs with their glucose oxidase (GOx)‐ mimic property, which results in unilateral production of hydrogen peroxide (H2O2). Then, L‐Arg is oxidized by the produced H2O2 to release NO, leading to the self‐propelled movement. It is found that the active movement of nanomotor promotes the AG‐DMSNs ability to penetrate biofilm, thus achieving good biofilm clearance in vitro. More importantly, AG‐DMSNs nanomotor can eliminate the biofilm of methicillin‐resistant Staphylococcus aureus (MRSA) in vivo without causing damage to normal tissues. This nanomotor provides a new platform for the treatment of bacterial infections.
Nitric oxide (NO)‐driven nanomotor based on L‐Arg and AuNPs loaded dendritic mesoporous silica nanoparticles (AG‐DMSNs) is fabricated. The cascade catalytically released NO‐driven nanomotor can trigger the autonomous movement. The NO‐driven nanomotor can penetrate deeply into biofilm, which disperses EPS and destroys bacterial cell membrane.
Regulation of angiogenesis is a great challenge for effective anticancer therapy. Generally, anti‐angiogenic therapies are focused on inhibition of inducers involved in pro‐angiogenic communication ...pathways. Despite the great potential of anti‐angiogenic therapy, engineering efficient angiogenesis inhibition agents (AIAs) is still a formidable challenge, since most anti‐angiogenic therapies are limited due to the cancer recurrence via compensatory expression of different angiogenic mediators. Herein, we present a new strategy of near‐infrared‐II (NIR‐II) responsive hydrogel AIAs, constructed by incorporation of nitric oxide (NO) precursor (BNN6) and 2D WO2.9 nanosheets within hydrogel (WB@hydrogel). Because of the defect/2D engineering, the bandgap of the WO2.9 nanosheets narrows, which extends the absorption to the NIR‐II region. It offers a favorable NIR‐II controlled manner for NO generation through irradiation time and light intensity. The continuous supply of NO can activate the expression of wild‐type p53 protein and further reverse the transcriptional expression of pro‐ and anti‐angiogenic factors of the tumor microenvironment (TME), subsequently alternating pro‐angiogenic TME to anti‐angiogenic TME. In the murine tumor model, this method achieved high tumor growth inhibition (TGI) rate and excellent anti‐recurrence efficiency.
NO‐precursor BNN6 and WO2.9 nanosheets are uniformly encapsulated into agarose hydrogel. WO2.9 induced by hydrogenation reaction from WO3 offer NIR‐II inertia hydrogel ability of NIR‐II response. With the controllable release of NO under NIR‐II laser irradiation, NO penetrates into deep tumor interiority and reprograms the tumor pro‐angiogenetic environment, achieving effective vessels eradication in tumor sites.
A new strategy is proposed to fabricate adaptable protein‐based hydrogel networks with both injectable and self‐healable properties. By mixing proteins and metal ions under alkaline conditions, the ...metal ions can crosslink proteins into protein–metal ion dynamic networks. Subsequently, the metal ions can react with the cysteine residues of protein to in situ form corresponding metal sulfide NPs with ultra‐small size, which leads to nanocomposite hydrogels with adaptable structures. This approach is general and a series of metal sulfide NP in situ embedded nanocomposite hydrogels were obtained. As an example, a Bi2S3–BSA hydrogel with tunable networks is shown to serve as an injectable, self‐healable photothermal agent for the treatment of tumors. Our finding paves a new avenue for the preparation of injectable and self‐healable hydrogels with potential applications in biomedicine.
Dynamic protein–metal ion networks were developed for the fabrication of adaptable hydrogels with both injectable and self‐healable properties. Metal ions within the dynamic networks can react with cysteine residues of protein to in situ transform into metal sulfide NPs, leading to injectable, self‐healable and metal sulfide embedded hybrid hydrogels with high photothermal efficiency, which can be utilized for photothermal therapy against tumors.
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