Organic Dye Molecule Intercalated Vanadium Oxygen Hydrate Enables High-Performance Aqueous Zinc-Ion Storage.

Although the layered vanadium oxide-based materials have been considered to be one of the candidates for aqueous Zn-ion batteries (AZIBs), it still faces inevitable challenges of unsatisfactory capacities and sluggish kinetics because of strong electrostatic interactions between Zn-ions and structure lattice. This work addresses the strategy of pre-inserting guest materials to vanadium oxide cathode using different intercalants. To achieve this goal, the small organic dye molecules, methyl orange (MO), and methylene blue (MB) are proposed as the intercalants for vanadium oxygen hydrate (VOH). It has been demonstrated that use of these intercalants can facilitate reaction kinetics between Zn2+ and VOH, leading to an improvement of specific capacity (293 mAh g-1 at 0.3 A g-1 for MO-VOH and 311 mAh g-1 for MB-VOH) compared to VOH, a large enhancement of excellent energy density (237.1 Wh kg-1 for MO-VOH, 232.3 Wh kg-1 for MB-VOH), and a prolong lifespan operation at 3 A g-1 . The mechanism studies suggest that the weakened electrostatic interactions between the Zn-ions and V-O lattice after intercalating organic molecules contribute to boosting the electrochemical performance of AZIBs unveiled by charge density difference and binding energy.

Achieving deep intratumoral penetration and multimodal combined therapy for tumor through algal photosynthesis.

BACKGROUND: Elevated interstitial fluid pressure within tumors, resulting from impaired lymphatic drainage, constitutes a critical barrier to effective drug penetration and therapeutic outcomes. RESULTS: In this study, based on the photosynthetic characteristics of algae, an active drug carrier (CP@ICG) derived from Chlorella pyrenoidosa (CP) was designed and constructed. Leveraging the hypoxia tropism and phototropism exhibited by CP, we achieved targeted transport of the carrier to tumor sites. Additionally, dual near-infrared (NIR) irradiation at the tumor site facilitated photosynthesis in CP, enabling the breakdown of excessive intratumoral interstitial fluid by generating oxygen from water decomposition. This process effectively reduced the interstitial pressure, thereby promoting enhanced perfusion of blood into the tumor, significantly improving deep-seated penetration of chemotherapeutic agents, and alleviating tumor hypoxia. CONCLUSIONS: CP@ICG demonstrated a combined effect of photothermal/photodynamic/starvation therapy, exhibiting excellent in vitro/in vivo anti-tumor efficacy and favorable biocompatibility. This work provides a scientific foundation for the application of microbial-enhanced intratumoral drug delivery and tumor therapy.

CdSe@CdS quantum dot-sensitized Au/α-Fe2O3 structure for photoelectrochemical detection of circulating tumor cells.

Circulating tumor cells (CTCs) are the important biomarker for cancer diagnosis and individualized treatment. However, due to the extreme rarity of CTCs (only 1-10 CTCs are found in every milliliter of peripheral blood) high sensitivity and selectivity are urgently needed for CTC detection. Here, a sandwich PEC cytosensor for the ultrasensitive detection of CTCs was developed using the photoactive material Au NP/-Fe2O3 and core-shell CdSe@CdS QD sensitizer. In the proposed  protocol, the CdSe@CdS QD/Au NP/α-Fe2O3-sensitized structure with cascade band-edge levels could evidently promote the photoelectric conversion efficiency due to suitable light absorption and efficient electron-hole pair recombination inhibition. Additionally, a dendritic aptamer-DNA concatemer was constructed for highly efficient capture of MCF-7 cells carrying CdSe@CdS QDs, a sensitive material. The linear range of this proposed signal-on PEC sensing method was 300 cell mL-1 to 6 × 105 cell mL-1 with a detection limit of 3 cell mL-1, and it demonstrated an ultrasensitive response to CTCs. Furthermore, this PEC sensor enabled accurate detection of  CTCs in serum samples. Hence, a promising strategy for CTC detection in clinical diagnosis was developed based on CdSe@CdS QD-sensitized Au NP/α-Fe2O3-based PEC cytosensor with dendritic aptamer-DNA concatemer.

Cyclized Polyacrylonitrile as a Promising Support for Single Atom Metal Catalyst with Synergistic Active Site.

Metal single atom catalysts (SAC) have been successfully used in heterogeneous catalysis but developing a scalable and economic support for SAC is still a great challenge. Here, cyclized polyacrylonitrile (CPAN) is proposed as a promising support for single atom metal catalysts. CPAN can be easily prepared from cheap industrial product polyacrylonitrile (PAN), which has excellent processability. A series of SAC on CPAN (M/CPAN, M = Ag, Cu, Ru) are designed and the catalytic activities of the as synthesized M/CPAN are investigated by the model reduction reaction of p-nitrophenol (4-NP). M/CPAN presents excellent catalytic performance with high stability and theoretical calculations elucidate that Ag/CPAN synergistically catalyze 4-NP reduction following the Langmuir-Hinshelwood (L-H) mechanism with 4-NP preferentially adsorbing at the Ag sites and H adsorbing at the bridge C sites. These results, for the first time, reveal that the single atom on CPAN can catalyze 4-NP reduction efficiently. This methodology provides a convenient route for the preparation of a variety of SAC, and this strategy is readily scalable and holds great potential in catalytic applications.

Engineering Oxygen Vacancies on Mixed-Valent Mesoporous α-MnO2 for High-Performance Asymmetric Supercapacitors.

Intrinsically poor conductivity and sluggish ion-transfer kinetics limit the further development of electrochemical storage of mesoporous manganese dioxide. In order to overcome the challenge, defect engineering is an effective way to improve electrochemical capability by regulating electronic configuration at the atomic level of manganese dioxide. Herein, we demonstrate effective construction of defects on mesoporous α-MnO2 through simply controlling the degree of redox reaction process, which could obtain a balance between Mn3+/Mn4+ ratio and oxygen vacancy concentration for efficient supercapacitors. The different structures of α-MnO2 including the morphology, specific surface area, and composition are successfully constructed by tuning the mole ratio of KMnO4 to Na2SO3. The electrode materials of α-MnO2-0.25 with an appropriate Mn3+/Mn4+ ratio and abundant oxygen vacancy showed an outstanding specific capacitance of 324 F g-1 at 0.5 A g-1, beyond most reported MnO2-based materials. The asymmetric supercapacitors formed from α-MnO2-0.25 and activated carbon can present an energy density as high as of 36.33 W h kg-1 at 200 W kg-1 and also exhibited good cycle stability over a wide voltage range from 0 to 2.0 voltage (kept at approximately 98% after 10 000 cycles in galvanostatic cycling tests) and nearly 100% Coulombic efficiency. Our strategy lays a foundation for fine regulation of defects to improve charge-transfer kinetics.

Over-Reduction-Controlled Mixed-Valent Manganese Oxide with Tunable Mn2+/Mn3+ Ratio for High-Performance Asymmetric Supercapacitor with Enhanced Cycling Stability.

Manganese oxides composed of various valence states Mnx+ (x = 2, 3, and 4) have attracted wide attention as promising electrode materials for asymmetric supercapacitor. However, the poor electrical conductivity limited their performance and application. Appropriate regulation content of Mnx+ in mixed-valent manganese oxide can tune the electronic structure and further improve their conductivity and performance. Herein, we prepared manganese oxides with different Mn2+/Mn3+ ratios through an over-reduction (OR) strategy for tuning the internal electron structure of mixed-valent manganese, which could make these material oxides a good platform for researching the structure-property relationships. The Mn2+/Mn3+ ratio of manganese oxide could be precisely tuned from 0.6 to 1.7 by controlling the amount of reducing agent for manipulating the redox processes, where the manganese oxide electrode with the most appropriate Mn2+/Mn3+ ratio, as 1.65 (OR4) exhibits large capacitance (274 F g-1) and the assembling asymmetric supercapacitors by combining OR4 (positive) and the commercial activated carbon (as negative) achieved large 2.0 V voltage window and high energy density of 27.7 Wh kg-1 (power density of 500 W kg-1). The cycle lifespan of the OR4//AC could keep about 92.9% after 10 000-cycle tests owing to the Jahn-Teller distortion of the Mn(III)O6 octahedron, which is more competitive compared to other work. Moreover, a red-light-emitting diode (LED) can easily be lit for 15 min by two all-solid supercapacitor devices in a series.

Strategic measurement for the axis-orientation and electro-optic coefficient of BaTiO3 crystal thin-film grown on MgO crystal with polarization modulations: erratum.

In this erratum the set of Eqs. (2a) and (2b), Eqs. (4) and (5), and the corresponding figure and values in the text of Opt. Lett.45, 4215 (2019)OPLEDP0146-959210.1364/OL.44.004215 have been updated.

Strategic measurement for the axis orientation and electro-optic coefficient of BaTiO3 crystal thin film grown on MgO crystal with polarization modulations.

BaTiO3 crystal thin film has been investigated to realize electro-optic (EO) devices due to its ultrahigh EO effect, but not much research has been focused on the correct axis orientation and EO coefficient. In this Letter, with a BaTiO3 crystal film grown by pulse laser deposition technique on ⟨100⟩ MgO crystal substrate, an embedded device configuration having the two-step etched waveguide/electrode scheme is designed to reach a high optic-electrical field interaction efficiency, and a 45° outside electric field with an in-plane axis is set to fit the possibility of the a-axis or c-axis orientation of the BaTiO3 crystal film. Then, through a poling process to the sample, the 1π, 2π, and 3π EO modulations of linear polarization are implemented at 4.9, 9.3, and 11.8 V, respectively, and a decremental voltage period is found. Thereby, a c-axis oriented BaTiO3 crystal film is determined, so that the nonlinear modulation equation is exploited. Finally, with an overlap of 1π, 2π, and 3π modulations, the coherent EO coefficient r51 and birefringence of 606 pm/V and -0.0215 are obtained, resulting in one (Vπ)2L value of 68 (V2·mm).

A universal nanoreactor triggering butterfly effect for encouraging Fenton/Fenton-like reactions and chemodynamic therapy.

Fenton/Fenton-like reaction induced chemical dynamic therapy (CDT) has been widely recognized in tumor therapy. Due to the low efficiency of conversion from high-valent metal ions (M(n+1)+) to low-valent ions (Mn+) in the Fenton/Fenton-like catalytic process, enhancing the conversion efficiency safely and effectively would create a great opportunity for the clinical application of CDT. In the study, a universal nanoreactor (NR) consisting of liposome (Lip), tumor cell membrane (CM), and bis(2,4,5-trichloro-6-carboxyphenyl) oxalate (CPPO) is developed to tackle this challenge. The CPPO was first discovered to decompose under weak acidity and H2O2 conditions to generate carboxylic acids (R'COOH) and alcohols (R'OH) with reducibility, which will reduce M(n+1)+ to Mn+ and magnify the effect of CDT. Furthermore, glucose oxidase (GOx) was introduced to decompose glucose in tumor and generate H2O2 and glucose acid, which promote the degradation of CPPO, further strengthening the efficiency of CDT, leading to a butterfly effect. This demonstrated that the butterfly effect triggered by NR and GOx encourages Fenton/Fenton-like reactions of Fe3O4 and MoS2, thereby enhancing the tumor inhibition effect. The strategy of combining GOx and CPPO to strengthen the Fenton/Fenton-like reaction is a universal strategy, which provides a new and interesting perspective for CPPO in the application of CDT, reflecting the exquisite integration of Fenton chemistry and catalytic medicine.

Boosting photo-thermal co-catalysis CO2 methanation by tuning interface electron transfer via Mott-Schottky heterojunction effect.

Photo-thermal co-catalytic reduction of CO2 to synthesize value-added chemicals presents a promising approach to addressing environmental issues. Nevertheless, traditional catalysts exhibit low light utilization efficiency, leading to the generation of a reduced number of electron-hole pairs and rapid recombination, thereby limiting catalytic performance enhancement. Herein, a Mott-Schottky heterojunction catalyst was developed by incorporating nitrogen-doped carbon coated TiO2 supported nickel (Ni) nanometallic particles (Ni/x-TiO2@NC). The optimal Ni/0.5-TiO2@NC sample displayed a conversion rate of 71.6 % and a methane (CH4) production rate of 65.3 mmol/(gcat·h) during photo-thermal co-catalytic CO2 methanation under full-spectrum illumination, with a CH4 selectivity exceeding 99.6 %. The catalyst demonstrates good stability as it shows no decay after two reaction cycles. The Mott-Schottky heterojunction catalysts display excellent efficiency in separating photo-generated electron-hole pairs and elevate the catalysts' temperature, thus accelerating the reaction rate. The in-situ experiments revealed that light-induced electron transfer effectively facilitates H2 dissociation and enhances surface defects, thereby promoting CO2 adsorption. This study introduces a novel approach for developing photo-thermal catalysts for CO2 reduction, aiming to enhance solar energy utilization and facilitate interface electron transfer.

Nanomedicine alleviates doxorubicin-induced cardiotoxicity and enhances chemotherapy synergistic chemodynamic therapy.

Doxorubicin (DOX) is widely used in clinic as a broad-spectrum chemotherapy drug, which can enhance the efficacy of chemodynamic therapy (CDT) by interfering tumor-related metabolize to increase H2O2 content. However, DOX can induce serious cardiomyopathy (DIC) due to its oxidative stress in cardiomyocytes. Eliminating oxidative stress would create a significant opportunity for the clinical application of DOX combined with CDT. To address this issue, we introduced sodium ascorbate (AscNa), the main reason is that AscNa can be catalyzed to produce H2O2 by the abundant Fe3+ in the tumor site, thereby enhancing CDT. While the content of Fe3+ in heart tissue is relatively low, so the oxidation of AscNa had tumor specificity. Meanwhile, due to its inherent reducing properties, AscNa could also eliminate the oxidative stress generated by DOX, preventing cardiotoxicity. Due to the differences between myocardial tissue and tumor microenvironment, a novel nanomedicine was designed. MoS2 was employed as a carrier and CDT catalyst, loaded with DOX and AscNa, coating with homologous tumor cell membrane to construct an acid-responsive nanomedicine MoS2-DOX/AscNa@M (MDA@M). In tumor cells, AscNa enhances the synergistic therapy of DOX and MoS2. In cardiomyocytes, AscNa could effectively reduce the cardiomyopathy induced by DOX. Overall, this study enhanced the clinical potential of chemotherapy synergistic CDT.

Self-healing of surface defects on Zn electrode for stable aqueous zinc-ion batteries via manipulating the electrode/electrolyte interphases.

The reversibility and stability of aqueous zinc-ion batteries are largely limited by inevitable parasitic reactions at the interface and uncontrollable dendrite growth. Inspired by self-healing smart electronic materials, we propose a confinement strategy with gelatin, an amphiphilic macromolecule, as additive to regulate the deposition behavior of Zn ions and utilize the dendrites to fill the surface defects formed by inevitable interfacial parasitic reactions. Absorbed gelatin molecules impede H2O reaching Zn electrode surface to enhance the anticorrosion behavior and adjust the local pH value, which is a "smart" way to stabilize the electrode/electrolyte interphase. Additionally, the confined effect of absorbed gelatin molecules on Zn2+ and "electrostatic shield" formed from positive charged -CN3H5+ suppress 2D diffusion and accumulation of Zn2+, guiding Zn continuously depositing inside the defect during electrochemical cycling, then self-healing of electrode surface defects is achieved. Under the synergetic effects of these merits, Zn electrode demonstrates almost unchangeable surface after soaking in the electrolyte for 10 days, and stably cycle more than 1100 h at 0.5 mA cm-2 and 1300 h at 3.0 mA cm-2 in symmetric cell. In addition, the full batteries using the base electrolyte with 0.5 and 1.0 g/L gelatin can stably cycle for 3000 cycles.

Dual-activity nanozyme to initiate tandem catalysis for doubly enhancing ATP-depletion anti-tumor therapy.

Nanozymes can regulate metabolism to achieve precise anti-tumor therapy. However, the application of nanozymes with single catalytic properties is limited by complex tumor microenvironment (TME). Herein, we report a rarely discovered nanozyme ruthenium (Ru), which has double catalytic activity of glucose-oxidase-like (GOx-like) activity and peroxidase-like (POD-like) activity. Importantly, the GOx-like activity of Ru was proposed for the first time, which can catalyze glucose and O2 to product H2O2. And then, Ru nanozyme can connect the tandem catalysis to enhance various tumor therapy. Firstly, the atovaquone (ATO) and Ru NPs were covered with a hybrid membrane of tumor cells and liposomes to obtain Ru@ATO-Lip/M with homologous targeting. Due to the enhanced permeability and retention (EPR) effect and the tumor targeting, the Ru@ATO-Lip/M NPs could be efficiently delivered to tumor and taken up by tumor cells. Subsequently, the acidic environment of tumor activated Ru to catalyze H2O2 producing OH (Fenton-like reaction). Meanwhile, newly discovered ability of Ru catalyzed glucose and O2 to produce gluconic acid and H2O2, which provided sufficient substrates (H2O2) for continuously generating more OH. Therefore, Ru nanozyme aggravated the starvation and chemodynamic therapy (CDT). Further, ATO improved the hypoxia of the tumor microenvironment, achieving steadily synergistic anti-tumor effect. This study verified the glucose oxidase-like properties of Ru NPs for the first time, and the strategy enhanced the synergistic anti-tumor effects by CDT and starvation therapy, which provided a basis for further exploration of Ru nanozyme activity and application on antitumor.

MoS2 nanoflower-mediated enhanced intratumoral penetration and piezoelectric catalytic therapy.

The absence of lymphatic vessels in tumors leads to the retention of interstitial fluid, and the formation of an inverse pressure difference between the tumor and blood vessels hinders drug delivery deep into the tumor, which leads to tumor recurrence and metastasis. Therefore, we designed a novel strategy to downregulate tumor interstitial fluid pressure (TIFP) by water splitting in the tumor interstitium based on piezoelectric catalysis nanomedicine. First, the chemotherapeutic drug doxorubicin (DOX) was loaded on the piezoelectric catalytic material MoS2 and then encapsulated with tumor cell membrane (CM) to obtain MD@C. MD@C could not only target the tumor through homologous targeting but, more importantly, also triggered piezoelectric catalytic water splitting under ultrasound (US) stimulation; as a result, the TIFPs of U14 and PAN02 tumor-bearing mice were reduced to 57.14% and 45.5%, respectively, and the tumor inhibition rates of MD@C were 96.75% and 99.21%, which increased the perfusion of blood-derived drugs in the tumors. Moreover, the hydroxyl radicals generated by piezoelectric catalysis could effectively inhibit the growth of tumors in combination with DOX. Consequently, the piezoelectric catalytic water splitting strategy of MD@C can enhance drug delivery, providing a new universal platform for the treatment of solid malignant tumors.

High Energy Density in Combination with High Cycling Stability in Hybrid Supercapacitors.

Hybrid supercapacitors are considered the next-generation energy storage equipment due to their superior performance. In hybrid supercapacitors, battery electrodes need to have large absolute capacities while displaying high cycling stability. However, enhancing areal capacity via decreasing the size of electrode materials results in reductions in cycling stability. To balance the capacity-stability trade-off, rationally designed proper electrode structures are in urgent need and still of great challenge. Here we report a high-capacity and high cycling stability electrode material by developing a nickel phosphate lamination structure with ultrathin nanosheets as building blocks. The nickel phosphate lamination electrode material exhibits a large specific capacity of 473.9 C g-1 (131.6 mAh g-1, 1053 F g-1) at 2.0 A g-1 and only about 21% capacity loss at 15 A g-1 (375 C g-1, 104.2 mAh g-1, 833.3 F g-1) in 6.0 M KOH. Furthermore, hybrid supercapacitors are constructed with nickel phosphate lamination and activated carbon (AC), possessing high energy density (42.1 Wh kg-1 at 160 W kg-1) as well as long cycle life (almost 100% capacity retention after 1000 cycles and 94% retention after 8000 cycles). The electrochemical performance of the nickel phosphate lamination structure not only is commensurate with the nanostructure or ultrathin materials carefully designed in supercapacitors but also has a longer cycling lifespan than them. The encouraging results show the great potential of this material for energy storage device applications.

Nonconfinement growth of edge-curved molecular crystals for self-focused microlasers.

Synthesis of single-crystalline micro/nanostructures with curved shapes is essential for developing extraordinary types of optoelectronic devices. Here, we use the strategy of liquid-phase nonconfinement growth to controllably synthesize edge-curved molecular microcrystals on a large scale. By varying the molecular substituents on linear organic conjugated molecules, it is found that the steric hindrance effect could minimize the intrinsic anisotropy of molecular stacking, allowing for the exposure of high-index crystal planes. The growth rate of high-index crystal planes can be further regulated by increasing the molecular supersaturation, which is conducive to the cogrowth of these crystal planes to form continuously curved-shape microcrystals. Assisted by nonrotationally symmetric geometry and optically smooth curvature, edge-curved microcrystals can support low-threshold lasing, and self-focusing directional emission. These results contribute to gaining an insightful understanding of the design and growth of functional molecular crystals and promoting the applications of organic active materials in integrated photonic devices and circuits.

Aptamer-mediated DNA concatemer functionalized magnetic nanoparticles for reversible capture and release of circulating tumor cells.

Effectively capturing, releasing, and reanalyzing circulating tumor cells (CTCs) are critical in cancer diagnosis and individualized treatment. Traditional immunomagnetic separation has disadvantages of low sensitivity and specificity, and is time-consuming and costly in CTCs capture. It is also easily disturbed by the microenvironment in releasing and analyzing CTCs. Here, we proposed an aptamer-mediated DNA concatemer functionalized magnetic nanoparticles (MNPs-AMDC) for the reversible capture and release of CTCs. In this study, aptamers were used both for efficiently capturing CTCs without complicated assembly steps and stimulus-response switch for releasing CTCs with little influence on cellular activity. The MNPs-AMDC was demonstrated to effectively capture (83%) and release CTCs with a good viability rate (92%). Moreover, this device was also tested in clinical blood samples, which would provide a universal tool for diagnosing cancer and treating individuals.

Gaseous microenvironmental remodeling of tumors for enhanced photo-gas therapy and real-time tracking.

The gaseous microenvironment (GME) of tumors is rapidly becoming a new concern for nanotechnology-mediated oncotherapy. Here, we constructed a tumor/near-infrared (NIR) light-responsive nanoplatform to generate O2 and NO for remodeling the GME of tumors and phototherapy. The biocompatible and pyrolytic polydopamine was used to load indocyanine green, NONOate, and MnO2 NPs as a nanoenzyme (PINM). Then, HA was modified on the PINM to form the final nanoplatform (PINMH). PINMH can target tumors favorably due to the modification of HA. Under the NIR light irradiation, PINM converts the light and O2 to hyperpyrexia (58.5 °C) and cytotoxic 1O2. MnO2 NPs catalyze the H2O2 overexpressed in tumors to O2, which increases the amount of 1O2. Moreover, NONOate decomposes to NO (100 µM) under hyperpyrexia, thus leading to the gas therapy. The results verified that the responsive nanoplatform with precise gaseous regulation and phototherapy exhibited a superior anti-tumor effect (V/V0 = 1.2) and biosafety. In addition, PINMH can be tracked in real-time via magnetic resonance imaging. In this study, an intelligent nano-platform integrated with diagnosis and treatment was developed, which used the phototherapy technology to reshape GME and achieve good anti-tumor effects, aiming to provide an innovative and reasonable strategy for the development of tumor treatment.

Plasmonic enhanced enzyme activity by catalytic cascade induced mutual benefit tumor starvation/immune/photothermal therapy.

Single tumor starvation therapy can activate other signaling pathways in tumor cells and easily induce tumor cell metastasis. This research proposes an intelligent nanoparticle, which is effectively combined with plasmonic and immunotherapy to realize a new strategy of "upstream consumption and downstream blocking" of nutrients in tumor sites. The intelligent nanoparticle (Ag-G/C@M) was composed of Ag NCs loaded with glucose oxidase (GOx), catalase (CAT) and coated with the tumor cytomembrane (M). Homologous targeting of tumor cytomembrane facilitated more delivery of Ag-G/C@M to tumor sites and then the plasmonic excited from Ag-G/C@M can increase the catalytic efficiency of the enzymatic reaction. Hydrogen peroxide (H2O2) produced by Ag-G/C@M through the consumption of glucose is further catalyzed by CAT to produce oxygen (O2). This self-reinforcing cascade reaction not only consumes the nutrients of tumor cells, but also the plasmonic-induced photothermal therapy can further stimulate the immune system to produce interferon-γ (IFN-γ), blocking angiogenesis and restricting the nutrient supply of tumor cells. This strategy takes the nutrition necessary for cell survival as the entry point, through endogenous continuous consumption of intracellular nutrients and containment of exogenous supplementation, combined with plasmonic thermal effect and immunotherapy to kill tumor cells, which provides a new way of treating cancer safely and effectively.

Diagnostic and therapeutic nanoenzymes for enhanced chemotherapy and photodynamic therapy.

Nanozymes, as a kind of artificial mimic enzymes, have superior catalytic capacity and stability. As lack of O2 in tumor cells can cause resistance to drugs, we designed drug delivery liposomes (MnO2-PTX/Ce6@lips) loaded with catalase-like nanozymes of manganese dioxide nanoparticles (MnO2 NPs), paclitaxel (PTX) and chlorin e6 (Ce6) to consume tumor's native H2O2 and produce O2. Based on the catalysis of MnO2 NPs, a large amount of oxygen was produced by MnO2-PTX/Ce6@lips to burst the liposomes and achieve a responsive release of the loaded drug (paclitaxel), and the released O2 relieved the chemoresistance of tumor cells and provided raw materials for photodynamic therapy. Subsequently, MnO2 NPs were decomposed into Mn2+ in an acidic tumor environment to be used as contrast agents for magnetic resonance imaging. The MnO2-PTX/Ce6@lips enhanced the efficacy of chemotherapy and photodynamic therapy (PDT) in bearing-tumor mice, even achieving complete cure. These results indicated the great potential of MnO2-PTX/Ce6@lips for the modulation of the TME and the enhancement of chemotherapy and PDT along with MRI tracing in the treatment of tumors.