ABSTRACT
BACKGROUND: Sesterterpenoids are rare species among the terpenoids family. Ophiobolins are sesterterpenes with a 5-8-5 tricyclic skeleton. The oxidized ophiobolins exhibit significant cytotoxic activity and potential medicinal value. There is an urgent need for large amounts of ophiobolins supplication for drug development. The synthetic biology approach has been successfully employed in lots of terpene compound production and inspired us to develop a cell factory for ophiobolin biosynthesis. RESULTS: We developed a systematic metabolic engineering strategy to construct an ophiobolin biosynthesis chassis based on Saccharomyces cerevisiae. The whole-cell biotransformation methods were further combined with metabolic engineering to enhance the expression of key ophiobolin biosynthetic genes and improve the supply of precursors and cofactors. A high yield of 5.1 g/L of ophiobolin F was reached using ethanol and fatty acids as substrates. To accumulate oxidized ophiobolins, we optimized the sources and expression conditions for P450-CPR and alleviated the toxicity of bioactive compounds to cells through PDR engineering. We unexpectedly obtained a novel ophiobolin intermediate with potent cytotoxicity, 5-hydroxy-21-formyl-ophiobolin F, and the known bioactive compound ophiobolin U. Finally, we achieved the ophiobolin U titer of 128.9 mg/L. CONCLUSIONS: We established efficient cell factories based on S. cerevisiae, enabling de novo biosynthesis of the ophiobolin skeleton ophiobolin F and oxidized ophiobolins derivatives. This work has filled the gap in the heterologous biosynthesis of sesterterpenoids in S. cerevisiae and provided valuable solutions for new drug development based on sesterterpenoids.
Subject(s)
Metabolic Engineering , Saccharomyces cerevisiae , Sesterterpenes , Sesterterpenes/metabolism , Saccharomyces cerevisiae/metabolism , Saccharomyces cerevisiae/geneticsABSTRACT
Monocyte-derived tumor-associated macrophages (Mo-TAMs) intensively infiltrate diffuse gliomas with remarkable heterogeneity. Using single-cell transcriptomics, we chart a spatially resolved transcriptional landscape of Mo-TAMs across 51 patients with isocitrate dehydrogenase (IDH)-wild-type glioblastomas or IDH-mutant gliomas. We characterize a Mo-TAM subset that is localized to the peri-necrotic niche and skewed by hypoxic niche cues to acquire a hypoxia response signature. Hypoxia-TAM destabilizes endothelial adherens junctions by activating adrenomedullin paracrine signaling, thereby stimulating a hyperpermeable neovasculature that hampers drug delivery in glioblastoma xenografts. Accordingly, genetic ablation or pharmacological blockade of adrenomedullin produced by Hypoxia-TAM restores vascular integrity, improves intratumoral concentration of the anti-tumor agent dabrafenib, and achieves combinatorial therapeutic benefits. Increased proportion of Hypoxia-TAM or adrenomedullin expression is predictive of tumor vessel hyperpermeability and a worse prognosis of glioblastoma. Our findings highlight Mo-TAM diversity and spatial niche-steered Mo-TAM reprogramming in diffuse gliomas and indicate potential therapeutics targeting Hypoxia-TAM to normalize tumor vasculature.
Subject(s)
Adrenomedullin , Brain Neoplasms , Glioblastoma , Tumor-Associated Macrophages , Humans , Glioblastoma/pathology , Glioblastoma/drug therapy , Glioblastoma/blood supply , Glioblastoma/genetics , Glioblastoma/metabolism , Animals , Adrenomedullin/genetics , Adrenomedullin/metabolism , Mice , Brain Neoplasms/drug therapy , Brain Neoplasms/pathology , Brain Neoplasms/blood supply , Brain Neoplasms/genetics , Brain Neoplasms/metabolism , Tumor-Associated Macrophages/metabolism , Neovascularization, Pathologic/genetics , Tumor Microenvironment , Isocitrate Dehydrogenase/genetics , Xenograft Model Antitumor Assays , Cell Line, Tumor , Macrophages/metabolism , Cell HypoxiaABSTRACT
Conjugated polymers (CPs) with low crystallinity are promising candidates for application in organic thermoelectrics (OTEs), particularly in flexible devices, because the disordered structures of these CPs can effectively accommodate dopants and ensure robust resistance to bending. However, n-doped CPs usually exhibit poor thermoelectric performance, which hinders the development of high-performance thermoelectric generators. Herein, we report an n-type CP (ThDPP-CNBTz) comprising two acceptor units: a thiophene-flanked diketopyrrolopyrrole and a cyano-functionalized benzothiadiazole. ThDPP-CNBTz shows a low LUMO energy level of below -4.20â eV and features low crystallinity, enabling high doping efficiency. Moreover, the dual-acceptor design enhances polaron delocalization, resulting in good thermoelectric performance. After n-doping, ThDPP-CNBTz exhibits an average electrical conductivity (σ) of 50.6â S cm-1 and a maximum power factor (PF) of 126.8â µW m-1 K-2, which is among the highest values reported for solution-processed n-type CPs to date. Additionally, a solution-processed flexible OTE device based on doped ThDPP-CNBTz exhibits a maximum PF of 70â µW m-1 K-2; the flexible device also shows remarkable resistance to bending strain, with only a marginal change in σ after 600 bending cycles. The findings presented in this work will advance the development of n-type CPs for OTE devices, and flexible devices in particular.
ABSTRACT
cGAS-STING signaling plays a critical role in radiotherapy (RT)-mediated immunomodulation. However, RT alone is insufficient to sustain STING activation in tumors under a safe X-ray dose. Here, we propose a radiosensitization cooperated with cGAS stimulation strategy by engineering a core-shell structured nanosized radiosensitizer-based cGAS-STING agonist, which is constituted with the hafnium oxide (HfO2) core and the manganese oxide (MnO2) shell. HfO2-mediated radiosensitization enhances immunogenic cell death to afford tumor associated antigens and adequate cytosolic dsDNA, while the GSH-degradable MnO2 sustainably releases Mn2+ in tumors to improve the recognition sensitization of cGAS. The synchronization of sustained Mn2+ supply with cumulative cytosolic dsDNA damage synergistically augments the cGAS-STING activation in irradiated tumors, thereby enhancing RT-triggered local and system effects when combined with an immune checkpoint inhibitor. Therefore, the synchronous radiosensitization with sustained STING activation is demonstrated as a potent immunostimulation strategy to optimize cancer radio-immuotherapy.
Subject(s)
Hafnium , Manganese Compounds , Neoplasms , Humans , Manganese Compounds/pharmacology , Oxides/pharmacology , Oxides/therapeutic use , Immunotherapy , Neoplasms/drug therapy , Neoplasms/radiotherapy , NucleotidyltransferasesABSTRACT
Infiltration and activation of intratumoral T lymphocytes are critical for immune checkpoint blockade (ICB) therapy. Unfortunately, the low tumor immunogenicity and immunosuppressive tumor microenvironment (TME) induced by tumor metabolic reprogramming cooperatively hinder the ICB efficacy. Herein, we engineered a lactate-depleting MOF-based catalytic nanoplatform (LOX@ZIF-8@MPN), encapsulating lactate oxidase (LOX) within zeolitic imidazolate framework-8 (ZIF-8) coupled with a coating of metal polyphenol network (MPN) to reinforce T cell response based on a "two birds with one stone" strategy. LOX could catalyze the degradation of the immunosuppressive lactate to promote vascular normalization, facilitating T cell infiltration. On the other hand, hydrogen peroxide (H2O2) produced during lactate depletion can be transformed into anti-tumor hydroxyl radical (â¢OH) by the autocatalytic MPN-based Fenton nanosystem to trigger immunogenic cell death (ICD), which largely improved the tumor immunogenicity. The combination of ICD and vascular normalization presents a better synergistic immunopotentiation with anti-PD1, inducing robust anti-tumor immunity in primary tumors and recurrent malignancies. Collectively, our results demonstrate that the concurrent depletion of lactate to reverse the immunosuppressive TME and utilization of the by-product from lactate degradation via cascade catalysis promotes T cell response and thus improves the effectiveness of ICB therapy.
Subject(s)
Metal-Organic Frameworks , Neoplasms , Humans , Lactic Acid/pharmacology , Metal-Organic Frameworks/pharmacology , Hydrogen Peroxide/pharmacology , T-Lymphocytes , Immunotherapy , Cell Line, Tumor , Tumor MicroenvironmentABSTRACT
Organic field-effect transistors (OFETs) have the advantages of low-cost, large-area processing and could be utilized in a variety of emerging applications. However, the generally large contact resistance (Rc) limits the integration and miniaturization of OFETs. The Rc is difficult to reduce due to an incompatibility between obtaining strong orbit coupling and the barrier height reduction. In this study, we developed an oxygen-induced barrier lowering strategy by introducing oxygen (O2) into the nanointerface between the electrodes and organic semiconductors layer and achieved an ultralow channel width-normalized Rc (Rc·W) of 89.8 Ω·cm and a high mobility of 11.32 cm2 V-1 s-1. This work demonstrates that O2 adsorbed at the nanointerface of metal-semiconductor contact can significantly reduce the Rc from both experiments and theoretical simulations and provides guidance for the construction of high-performance OFETs, which is conducive to the integration and miniaturization of OFETs.
ABSTRACT
Ferromagnetic semiconductors (FMS) enable simultaneous control of both charge and spin transport of charge carriers, and they have emerged as a class of highly desirable but rare materials for applications in spin field-effect transistors and quantum computing. Organic-inorganic hybrid perovskites with high compositional adjustability and structural versatility can offer unique benefits in the design of FMS but has not been fully explored. Here, a series of molecular FMSs based on the 2D organic-inorganic hybrid perovskite structure, namely (2ampy)CuCl4 , (3ampy)CuCl4 , and (4ampy)CuCl4 , is demonstrated, which exhibits high saturation magnetization, dramatic temperature-dependent conductivity change, and tunable ferromagnetic resonance. Magnetic measurements reveal a high saturation magnetization up to 18.56 emu g-1 for (4ampy)CuCl4 , which is one of the highest value among reported hybrid FMSs to date. Conductivity studies of the three FMSs demonstrate that the smaller adjacent octahedron distance in the 2D layer results in higher conductivity. Systematic ferromagnetic resonance investigation shows that the gyromagnetic ratio and Landau factor values are strongly dependent on the types of organic cations used. This work demonstrates that 2D hybrid perovskite materials can simultaneously possess both tunable long-range ferromagnetic ordering and semiconductivity, providing a straightforward strategy for designing and synthesizing high-performance intrinsic FMSs.
ABSTRACT
Tailoring the interface between organic semiconductor (OSC) and ferromagnetic (FM) electrodes, that is, the spinterface, offers a promising way to manipulate and optimize the magnetoresistance (MR) ratio of the organic spin valve (OSV) devices. However, the non-destructive in situ regulation method of spinterface is seldom reported, limiting its theoretical research and further application in organic spintronics. (La2/3 Pr1/3 )5/8 Ca3/8 MnO3 (LPCMO), a recently developed FM material, exhibits a strong electronic phase separation (EPS) property, and can be employed as an effective in situ spinterface adjuster. Herein, we fabricated a LPCMO-based polymer spin valve with a vertical configuration of LPCMO/poly(3-hexylthiophene-2,5-diyl) (P3HT)/Co, and emphasized the important role of LPCMO/P3HT spinterface in MR regulation. A unique competitive spin-scattering mechanism generated by the EPS characteristics of LPCMO inside the polymer spin valve was discovered by abstracting the anomalous non-monotonic MR value as a function of pre-set magnetic field (Bpre ) and temperature (T). Particularly, a record-high MR ratio of 93% was achieved in polymer spin valves under optimal conditions. These findings highlight the importance of interdisciplinary research between organic spintronics and EPS oxides and offer a novel scenario for multi-level storage via spinterface manipulation.
ABSTRACT
Radiotherapy (RT) is one of the important clinical treatments for local control of triple-negative breast cancer (TNBC), but radioresistance still exists. Ferroptosis has been recognized as a natural barrier for cancer progression and represents a significant role of RT-mediated anticancer effects, while the simultaneous activation of ferroptosis defensive system during RT limits the synergistic effect between RT and ferroptosis. Herein, we engineered a tumor microenvironment (TME) degradable nanohybrid with a dual radiosensitization manner to combine ferroptosis induction and high-Z effect based on metal-organic frameworks for ferroptosis-augmented RT of TNBC. The encapsulated l-buthionine-sulfoximine (BSO) could inhibit glutathione (GSH) biosynthesis for glutathione peroxidase 4 (GPX4) inactivation to break down the ferroptosis defensive system, and the delivered ferrous ions could act as a powerful ferroptosis executor via triggering the Fenton reaction; the combination of them induces potent ferroptosis, which could synergize with the surface decorated Gold (Au) NPs-mediated radiosensitization to improve RT efficacy. In vivo antitumor results revealed that the nanohybrid could significantly improve the therapeutic efficacy and antimetastasis efficiency based on the combinational mechanism between ferroptosis and RT. This work thus demonstrated that combining RT with efficient ferroptosis induction through nanotechnology was a feasible and promising strategy for TNBC treatment.
Subject(s)
Ferroptosis , Triple Negative Breast Neoplasms , Humans , Anesthetics, Local , Buthionine Sulfoximine , Fibrinolytic Agents , Glutathione , Cell Line, Tumor , Tumor MicroenvironmentABSTRACT
With the rapid development of nanotechnology and nanomedicine, there are great interests in employing nanomaterials to improve the efficiency of disease diagnosis and treatment. The clinical translation of hafnium oxide (HfO2 ), commercially namedas NBTXR3, as a new kind of nanoradiosensitizer for radiotherapy (RT) of cancers has aroused extensive interest in researches on Hf-based nanomaterials for biomedical application. In the past 20 years, Hf-based nanomaterials have emerged as potential and important nanomedicine for computed tomography (CT)-involved bioimaging and RT-associated cancer treatment due to their excellent electronic structures and intrinsic physiochemical properties. In this review, a bibliometric analysis method is employed to summarize the progress on the synthesis technology of various Hf-based nanomaterials, including HfO2 , HfO2 -based compounds, and Hf-organic ligand coordination hybrids, such as metal-organic frameworks or nanoscaled coordination polymers. Moreover, current states in the application of Hf-based CT-involved contrasts for tissue imaging or cancer diagnosis are reviewed in detail. Importantly, the recent advances in Hf-based nanomaterials-mediated radiosensitization and synergistic RT with other current mainstream treatments are also generalized. Finally, current challenges and future perspectives of Hf-based nanomaterials with a view to maximize their great potential in the research of translational medicine are also discussed.
Subject(s)
Antineoplastic Agents , Nanostructures , Neoplasms , Humans , Hafnium/chemistry , Nanostructures/chemistry , Neoplasms/diagnostic imaging , Neoplasms/therapy , Nanotechnology/methodsABSTRACT
Only a small proportion of patients with triple-negative breast cancer benefit from immune checkpoint inhibitor (ICI) targeting PD-1/PD-L1 signaling in combination with chemotherapy. Here, we discovered that therapeutic response to ICI plus paclitaxel was associated with subcellular redistribution of PD-L1. In our immunotherapy cohort of ICI in combination with nab-paclitaxel, tumor samples from responders showed significant distribution of PD-L1 at mitochondria, while non-responders showed increased accumulation of PD-L1 on tumor cell membrane instead of mitochondria. Our results also revealed that the distribution pattern of PD-L1 was regulated by an ATAD3A-PINK1 axis. Mechanistically, PINK1 recruited PD-L1 to mitochondria for degradation via a mitophagy pathway. Importantly, paclitaxel increased ATAD3A expression to disrupt proteostasis of PD-L1 by restraining PINK1-dependent mitophagy. Clinically, patients with tumors exhibiting high expression of ATAD3A detected before the treatment with ICI in combination with paclitaxel had markedly shorter progression-free survival compared with those with ATAD3A-low tumors. Preclinical results further demonstrated that targeting ATAD3A reset a favorable antitumor immune microenvironment and increased the efficacy of combination therapy of ICI plus paclitaxel. In summary, our results indicate that ATAD3A serves not only as a resistant factor for the combination therapy of ICI plus paclitaxel through preventing PD-L1 mitochondrial distribution, but also as a promising target for increasing the therapeutic responses to chemoimmunotherapy.
Subject(s)
B7-H1 Antigen , Mitophagy , Humans , ATPases Associated with Diverse Cellular Activities , Immunotherapy , Membrane Proteins , Mitochondria , Mitochondrial Proteins , Paclitaxel/pharmacology , Protein KinasesABSTRACT
Phase-change semiconductor is one of the best candidates for designing nonvolatile memory, but it has never been realized in organic semiconductors until now. Here, a phase-changeable and high-mobility organic semiconductor (3,6-DATT) is first synthesized. Benefiting from the introduction of electrostatic hydrogen bond (S···H), the molecular conformation of 3,6-DATT crystals can be reversibly modulated by the electric field and ultraviolet irradiation. Through experimental and theoretical verification, the tiny difference in molecular conformation leads to crystalline polymorphisms and dramatically distinct charge transport properties, based on which a high-performance organic phase-change memory transistor (OPCMT) is constructed. The OPCMT exhibits a quick programming/erasing rate (about 3 s), long retention time (more than 2 h), and large memory window (i.e., large threshold voltage shift over 30 V). This work presents a new molecule design concept for organic semiconductors with reversible molecular conformation transition and opens a novel avenue for memory devices and other functional applications.
ABSTRACT
We report the bi-polaron transport and magnetic field induced Pauli spin-blockade in solid-state molecular junctions (MJs) evidenced by a positive magnetoresistance (MR). The junction was made of thin layers of redox-active ruthenium polypyridyl-oligomers Ru(tpy)2 sandwiched between conducting amorphous carbon (a-C) electrodes. The redox-active Ru(tpy)2 molecule, which enables small polaron and deep traps in the charge transport of the Ru(tpy)2 MJ as revealed by the temperature-dependent current-voltage response, leads to the formation of the bi-polaron and magnetic field induced Pauli spin blockade, resulting into the MR. At the meantime, the reliable and controllable device performance renders a rigid thickness-dependent MR evolution. The bi-polaron transport revealed in our study underscores the importance of the multi-particle transport by molecular design in MJs and laid the foundation for magnetic-electronic function in molecular-scale devices.
ABSTRACT
With the successful marriage between nanotechnology and oncology, various high-Z element containing nanoparticles (NPs) are approved as radiosensitizers to overcome radiation resistance for enhanced radiotherapy (RT). Unfortunately, NPs themselves lack specificity to tumors. Due to the inherent tropism nature of malignant cells, mesenchymal stem cells (MSCs) emerge as cell-mediated delivery vehicles for functional NPs to improve their therapeutic index. Herein, radiosensitive bismuth selenide (Bi2 Se3 ) NPs-laden adipose-derived mesenchymal stromal cells (AD-MSCs/Bi2 Se3 ) are engineered for targeted RT of non-small cell lung cancer (NSCLC). The results reveal that the optimized intracellular loading strategy hardly affects cell viability, specific surface markers, or migration capability of AD-MSCs, and Bi2 Se3 NPs can be efficiently transported from AD-MSCs to tumor cells. In vivo biodistribution test shows that the Bi2 Se3 NPs accumulation in tumor is increased 20 times via AD-MSCs-mediated delivery. Therefore, AD-MSCs/Bi2 Se3 administration synchronized with X-ray irradiation controls the tumor progress well in orthotopic A549 tumor bearing mice. Considering that MSCs migrate better to irradiated tumor cells in comparison to nonirradiated ones and MSCs preferentially accumulate within lung tissues after systemic administration into accounts, the tumor-tropic MSCs/NPs system is feasible and promising for targeted RT treatment of NSCLC.
Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Mesenchymal Stem Cell Transplantation , Mesenchymal Stem Cells , Radiation-Sensitizing Agents , Animals , Carcinoma, Non-Small-Cell Lung/metabolism , Carcinoma, Non-Small-Cell Lung/radiotherapy , Cell Line, Tumor , Lung Neoplasms/metabolism , Lung Neoplasms/radiotherapy , Mesenchymal Stem Cell Transplantation/methods , Mice , Tissue DistributionABSTRACT
Tumor vasculature-targeting therapy either using angiogenesis inhibitors or vascular disrupting agents offers an important new avenue for cancer therapy. In this work, a tumor-specific catalytic nanomedicine for enhanced tumor ablation accompanied with tumor vasculature disruption and angiogenesis inhibition was developed through a cascade reaction with enzyme glucose oxidase (GOD) modified on Fe-based metal organic framework (Fe-MOF) coupled with anti-VEGFR2.The GOD enzyme could catalyze the intratumoral glucose decomposition to trigger tumor starvation and yet provide abundant hydrogen peroxide as the substrate for Fenton-like reaction catalyzed by Fe-MOF to produce sufficient highly toxic hydroxyl radicals for enhanced chemodynamic therapy and instantly attacked tumor vascular endothelial cells to destroy the existing vasculature, while the anti-VEGFR2 antibody guided the nanohybrids to target blood vessels and block the VEGF-VEGFR2 connection to prevent angiogenesis. Both in vitro and in vivo results demonstrated the smart nanohybrids could cause the tumor cell apoptosis and vasculature disruption, and exhibited enhanced tumor regression in A549 xenograft tumor-bearing mice model. This study suggested that synergistic targeting tumor growth and its vasculature network would be more promising for curing solid tumors. STATEMENT OF SIGNIFICANCE: Cooperative destruction of tumor cells and tumor vasculature offers a potential avenue for cancer therapy. Under this premise, a tumor-specific catalytic nanomedicine for enhanced tumor ablation accompanied with tumor vasculature disruption and new angiogenesis inhibition was developed through a cascade reaction with glucose oxidase modified on the surface of iron-based metal organic framework coupled with VEGFR2 antibody. The resulting data demonstrated that a therapeutic regimen targeting tumor growth as well as its vasculature with both existing vasculature disruption and neovasculature inhibition would be more potential for complete eradication of tumors.
Subject(s)
Metal-Organic Frameworks , Neoplasms , Animals , Catalysis , Cell Line, Tumor , Endothelial Cells/metabolism , Glucose Oxidase/chemistry , Humans , Metal-Organic Frameworks/chemistry , Metal-Organic Frameworks/pharmacology , Mice , Neoplasms/drug therapy , Neoplasms/metabolismABSTRACT
The hitherto elusive benzo[c]anthanthrenyl radical derivatives composed of seven fused six-membered rings are synthesized and isolated in the crystalline form, representing a laterally π-extended doublet open-shell graphene fragment compared to the phenalenyl and olympicenyl radical structures. X-ray crystallographic analysis revealed one-dimensional chain stacking with relatively close intermolecular contacts, which is an important precondition for achieving single-component conductors. The magnetic, optical, and redox properties are investigated in the solution phase. In combination with the good stability, such open-shell molecular systems have potentials as functional electronic materials.
ABSTRACT
With the recent success of immune checkpoint blockade (ICB) in cancer immunotherapy, there has been renewed interest in evaluating the combination of ICB inhibitors with radiotherapy (RT) in clinical trials in view of the localized RT-initiated vaccination effect, which can be augmented further by systemic immune-stimulating agents. Unfortunately, traditional RT/ICB accompanies severe toxicity from high-dose ionizing irradiation and low response rate from RT-aggravated immunosuppression, among which M2-type tumor-associated macrophages (TAMs) play an important role. Herein, CpG-decorated gold (Au) nanoparticles (CpG@Au NPs) were fabricated to improve the RT/ICB efficacy by immune modulation under low-dose X-ray exposure, where Au NPs served as radioenhancers to minimize the radiotoxicity, and yet acted as nanocarriers to deliver CpG, a toll-like receptor 9 agonist, to re-educate immunosuppressive M2 TAMs to immunostimulatory M1 counterparts, thus arousing innate immunity and meanwhile priming T cell activation. When combined with an anti-programmed death 1 antibody, irradiated CpG@Au led to consistent abscopal responses that efficiently suppressed distant tumors in a bilateral GL261 tumor-bearing model. This work thus demonstrates that CpG@Au-mediated macrophage reeducation could efficiently modulate the tumor-immune microenvironment for synergistic RT/ICB.
Subject(s)
Glioma/therapy , Gold/pharmacology , Immune Checkpoint Inhibitors/pharmacology , Immunotherapy , Nanocomposites/chemistry , Oligodeoxyribonucleotides/pharmacology , Tumor-Associated Macrophages/drug effects , Animals , Gold/chemistry , Immune Checkpoint Inhibitors/chemistry , Mice , Oligodeoxyribonucleotides/chemistry , Tumor Cells, Cultured , Tumor Microenvironment/drug effectsABSTRACT
The realization of a large low-field magnetoresistance (LFMR) effect in free-standing magnetic oxide films is a crucial goal toward promoting the development of flexible, low power consumption, and nonvolatile memory devices for information storage. La0.7Sr0.3MnO3 (LSMO) is an ideal material for spintronic devices due to its excellent magnetic and electronic properties. However, it is difficult to achieve both a large LFMR effect and high flexibility in LSMO films due to the lack of research on LFMR-related mechanisms and the strict LSMO growth conditions, which require rigid substrates. Here, we induced a large LFMR effect in an LSMO/mica heterostructure by utilizing a disorder-related spin-polarized tunneling effect and developed a simple transfer method to obtain free-standing LSMO films for the first time. Electrical and magnetic characterizations of these free-standing LSMO films revealed that all of the principal properties of LSMO were sustained under compressive and tensile conditions. Notably, the magnetoresistance of the processed LSMO film reached up to 16% under an ultrasmall magnetic field (0.1 T), which is 80 times that of a traditional LSMO film. As a demonstration, a stable nonvolatile multivalue storage function in flexible LSMO films was successfully achieved. Our work may pave the way for future wearable resistive memory device applications.
ABSTRACT
Radiotherapy (RT) plays a central role in curing malignant tumors. However, the treatment outcome is often impeded by low radiation absorption coefficients and radiation resistance of tumors along with normal tissue radio-toxicity. With the development of nanotechnology, nanomaterials in combination with RT offer the possibility to improve the therapeutic efficacy yet reduce side-effects. Metal-ligand coordination nanomaterials, including nanoscale metal-organic frameworks (NMOFs) and nanoscale coordination polymers (NCPs), formed by coordination interactions between inorganic metal ions/clusters with organic bridging ligands, have shown great potential in the field of radiation oncology in recent years in view of their unique advantages including the porous structure, high surface area, periodic frameworks, and diverse selections of both metal ions/clusters and organic ligands. In this review, we summarize the recent advances in NMOF/NCP-mediated synergistic RT in combination with hypoxia relief, chemotherapy, photodynamic therapy, photothermal therapy, chemodynamic therapy or immunotherapy, which emerged in the last 3 years, and describe cooperative enhancement interactions among these synergistic combinations. Moreover, the potential challenges and future prospects of this rapidly growing direction were also addressed.