Coronaviral ORF6 protein mediates inter-organelle contacts and modulates host cell lipid flux for virus production.

Lipid droplets (LDs) form inter-organelle contacts with the endoplasmic reticulum (ER) that promote their biogenesis, while LD contacts with mitochondria enhance ß-oxidation of contained fatty acids. Viruses have been shown to take advantage of lipid droplets to promote viral production, but it remains unclear whether they also modulate the interactions between LDs and other organelles. Here, we showed that coronavirus ORF6 protein targets LDs and is localized to the mitochondria-LD and ER-LD contact sites, where it regulates LD biogenesis and lipolysis. At the molecular level, we find that ORF6 inserts into the LD lipid monolayer via its two amphipathic helices. ORF6 further interacts with ER membrane proteins BAP31 and USE1 to mediate ER-LDs contact formation. Additionally, ORF6 interacts with the SAM complex in the mitochondrial outer membrane to link mitochondria to LDs. In doing so, ORF6 promotes cellular lipolysis and LD biogenesis to reprogram host cell lipid flux and facilitate viral production.

Actomyosin-dependent cell contractility orchestrates Zika virus infection.

Emerging pathogen infections, such as Zika virus (ZIKV), pose an increasing threat to human health, but the role of mechanobiological attributes of host cells during ZIKV infection is largely unknown. Here, we reveal that ZIKV infection leads to increased contractility of host cells. Importantly, we investigated whether host cell contractility contributes to ZIKV infection efficacy, from both the intracellular and extracellular perspective. By performing drug perturbation and gene editing experiments, we confirmed that disruption of contractile actomyosin compromises ZIKV infection efficiency, viral genome replication and viral particle production. By culturing on compliant matrix, we further demonstrate that a softer substrate, leading to less contractility of host cells, compromises ZIKV infection, which resembles the effects of disrupting intracellular actomyosin organization. Together, our work provides evidence to support a positive correlation between host cell contractility and ZIKV infection efficacy, thus unveiling an unprecedented layer of interplay between ZIKV and the host cell.

Dual Starvations Induce Pyroptosis for Orthotopic Pancreatic Cancer Therapy through Simultaneous Deprivation of Glucose and Glutamine.

Pancreatic cancer is a highly fatal disease, and existing treatment methods are ineffective, so it is urgent to develop new effective treatment strategies. The high dependence of pancreatic cancer cells on glucose and glutamine suggests that disrupting this dependency could serve as an alternative strategy for pancreatic cancer therapy. We identified the vital genes glucose transporter 1 (GLUT1) and alanine-serine-cysteine transporter 2 (ASCT2) through bioinformatics analysis, which regulate glucose and glutamine metabolism in pancreatic cancer, respectively. Human serum albumin nanoparticles (HSA NPs) for delivery of GLUT1 and ASCT2 inhibitors, BAY-876/V-9302@HSA NPs, were prepared by a self-assembly process. This nanodrug inhibits glucose and glutamine uptake of pancreatic cancer cells through the released BAY-876 and V-9302, leading to nutrition deprivation and oxidative stress. The inhibition of glutamine leads to the inhibition of the synthesis of the glutathione, which further aggravates oxidative stress. Both of them lead to a significant increase in reactive oxygen species, activating caspase 1 and GSDMD and finally inducing pyroptosis. This study provides a new effective strategy for orthotopic pancreatic cancer treatment by dual starvation-induced pyroptosis. The study for screening metabolic targets using bioinformatics analysis followed by constructing nanodrugs loaded with inhibitors will inspire future targeted metabolic therapy for pancreatic cancer.

Effects of Skeleton Structure of Mesoporous Silica Nanoadjuvants on Cancer Immunotherapy.

Mesoporous silica nanoparticles (MSNs) have been widely praised as nanoadjuvants in vaccine/tumor immunotherapy thanks to their excellent biocompatibility, easy-to-modify surface, adjustable particle size, and remarkable immuno-enhancing activity. However, the application of MSNs is still greatly limited by some severe challenges including the unclear and complicated relationships of structure and immune effect. Herein, three commonly used MSNs with different skeletons including MSN with tetrasulfide bonds (TMSN), MSN containing ethoxy framework (EMSN), and pure -Si-O-Si- framework of MSN (MSN) are comprehensively compared to study the impact of chemical construction on immune effect. The results fully demonstrate that the three MSNs have great promise in improving cellular immunity for tumor immunotherapy. Moreover, the TMSN performs better than the other two MSNs in antigen loading, cellular uptake, reactive oxygen species (ROS) generation, lymph node targeting, immune activation, and therapeutic efficiency. The findings provide a new paradigm for revealing the structure-function relationship of mesoporous silica nanoadjuvants, paving the way for their future clinical application.

Electron ionization mass spectrometry feature peak relationships combined with deep classification model to assist similarity algorithm for fast and accurate identification of compounds.

RATIONALE: Gas chromatography-mass spectrometry (GC-MS) combines chromatography and MS, providing full play to the advantages of high separation efficiency of GC, strong qualitative ability of MS, and high sensitivity of detector. In GC-MS data processing, determining the experimental compounds is one of the most important analytical steps, which is usually realized by one-to-one similarity calculations between the experimental mass spectrum and the standard mass spectrum library. Although the accuracy of the algorithm has been improved in recent years, it is still difficult to distinguish structurally similar mass spectra, especially isomers. At the same time, the library capacity is very large and increasing every year, and the algorithm needs to perform large numbers of calculations with irrelevant compounds in the library to recognize unknown compounds, which leads to a significant reduction in efficiency. METHODS: This work proposed to exclude a large number of irrelevant mass spectra by presearching, perform preliminary similarity calculations using similarity algorithms, and finally improve the accuracy of similarity calculations using deep classification models. The replica library of NIST17 is used as the query data, and the master library is used as the reference database. RESULTS: Compared with the traditional recognition algorithm, the preprocessing algorithm has reduced the time by 4.2 h, and by adding the deep learning models 1 and 2 as the final determination, the recognition accuracy has been improved by 1.9% and 6.5%, respectively, based on the original algorithm. CONCLUSIONS: This method improves the recognition efficiency compared to conventional algorithms and at the same time has better recognition accuracy for structurally similar mass spectra and isomers.

Sodium Citrate Nanoparticles Induce Dual-Path Pyroptosis for Enhanced Antitumor Immunotherapy through Synergistic Ion Overload and Metabolic Disturbance.

Metabolic reprogramming, as one of the characteristics of cancer, is associated with tumorigenesis, growth, or migration, and the modulation of metabolic pathways has emerged as a novel approach for cancer therapy. However, the conventional metabolism-mediated apoptosis process in tumor cells exhibits limited immunogenicity and inadequate activation of antitumor immunity. Herein, phospholipid-coated sodium citrate nanoparticles (PSCT NPs) are successfully prepared, which dissolve in tumor cells and then release significant amounts of citrate ions and Na+ ions. Massive quantities of ions lead to increased intracellular osmotic pressure, which activates the caspase-1/gasdermin D (GSDMD) mediated pyroptosis pathway. Simultaneously, citrate induces activation of the caspase-8/gasdermin C (GSDMC) pathway. The combined action of these two pathways synergistically causes intense pyroptosis, exhibiting remarkable antitumor immune responses and tumor growth inhibition. This discovery provides new insight into the potential of nanomaterials in modulating metabolism and altering cell death patterns to enhance antitumor immunotherapy.

Oxygen-Vacancy-Engineered W18 O49-x Nanobrush with a Suitable Band Structure for Highly Efficient Sonodynamic Therapy.

With the rapid development of external minimally invasive or noninvasive therapeutic modalities, ultrasound-based sonodynamic therapy (SDT) is a new alternative for treating deep tumors. However, inadequate sonosensitizer efficiency and poor biosecurity limit clinical applications. In this study, we prepared an oxygen-vacancy-engineered W18 O49-x nanobrush with a band gap of 2.79 eV for highly efficient SDT using a simple solvothermal method. The suitable band structures of the W18 O49-x nanobrush endows it with the potential to simultaneously produce singlet oxygen (1 O2 ), superoxide anions (⋅O2 - ), and hydroxyl radicals (⋅OH) under ultrasound irradiation. Additionally, abundant oxygen vacancies that serve as further charge traps that inhibit electron-hole recombination are incidentally introduced through one-step thermal reduction. Collectively, the in vitro and in vivo results demonstrate that the oxygen-vacancy-engineered W18 O49-x nanobrush delivers highly efficient reactive oxygen species (ROS) for SDT in a very biosafe manner. Overall, this study provides a new avenue for discovering and designing inorganic nanosonosensitizers with enhanced therapeutic efficiencies for use in SDT.

Glutathione Induced In situ Synthesis of Cu Single-Atom Nanozymes with Anaerobic Glycolysis Metabolism Interference for Boosting Cuproptosis.

Single-atom nanozyme (SAzyme) has sparked increasing interest for catalytic antitumor treatment due to their more tunable and diverse active sites than natural metalloenzymes in complex physiological conditions. However, it is usually a hard task to precisely conduct catalysis at tumor sites after intravenous injection of those SAzyme with high reactivity. Moreover, the explorations of SAzymes in the anticancer application are still in its infancy and need to be developed. Herein, an in situ synthesis strategy for Cu SAzyme was constructed to convert adsorbed copper ions into isolated atoms anchored by oxygen atoms (Cu-O2/Cu-O4) via GSH-responsive deformability of supports. Our results suggest that the in situ activation process could further facilitate the dissociation of copper ions and the consumption of glutathione, thereby leading to copper deposition in cytoplasm and triggering cuproptosis. Moreover, the in situ synthesis of Cu SAzyme with peroxidase-like activity enabled the intracellular reactive oxygen species production, resulting in specifically disturbance of copper metabolism pathway. Meanwhile, the in situ exposed glucose transporter (GLUT) inhibitor phloretin (Ph) can block the glycose uptake to boost cuproptosis efficacy. Overall, this in situ activation strategy effectively diminished the off-target effects of SACs-induced catalytic therapies and introduced a promising treatment paradigm for advancing cuproptosis-associated therapies.

Heterostructural Nanoadjuvant CuSe/CoSe2 for Potentiating Ferroptosis and Photoimmunotherapy through Intratumoral Blocked Lactate Efflux.

The desirable curative effect in clinical immunotherapy has been challenging due to the immunosuppressive tumor microenvironment (TME) with high lactic acid (LA) metabolism in solid tumors. Although targeting metabolic reprogramming of tumor cells can restore the survival and function of immune cells in the TME, it is also plagued by insufficient immunogenicity. Herein, an activatable immunomodulatory nanoadjuvant CuSe/CoSe2@syrosingopine (CSC@Syro) is constructed for simultaneously relieving immunosuppressive TME and boosting tumor immune response. Specifically, CuSe/CoSe2 (CSC) exhibits TME-activated glutathione (GSH) depletion and hydroxyl radical (•OH) generation for potential ferroptosis. Meanwhile, the remarkable photothermal conversion efficiency and elevated photocatalytic ROS level both promote CSC heterostructures to induce robust immunogenic cell death (ICD). Besides, the loaded syrosingopine inhibitor achieves LA metabolism blockade in cancer cells by downregulating the expression of monocarboxylate transporter 4 (MCT4), which could sensitize ferroptosis by intracellular milieu acidification and neutralize the acidic TME to alleviate immunosuppression. Hence, advanced metabolic modulation confers the potentiated immune infiltration of ICD-stimulated T lymphocytes and further reinforces antitumor therapy. In brief, CSC@Syro-mediated synergistic therapy could elicit potent immunogenicity and suppress tumor proliferation and metastasis effectually by integrating the tumor metabolic regulation and ferroptosis with immunotherapy.

Usnea Acid-Incorporated Ca2+ /Mn2+ Ions Reservoirs for Elevated Ion-Interference Therapy through Synergetic Biocatalysis and Osmolarity Imbalance.

Ion-interference therapy (IIT) utilizes ions to disturb intracellular biological processes and has been received increasing attention in tumor treatments recently. However, the low therapeutic efficiency still hinders its further biological applications. Herein, via a simple and one-pot gas diffusion process, polyethylene glycol (PEG)-modified Mn2+ ions and usnic acid (UA)-incorporated CaCO3 nanomaterials (PEG CaMnUA) as Ca2+ /Mn2+ ions reservoirs are prepared for magnetic resonance imaging (MRI)-guided UA-elevated IIT. Among PEG CaMnUA, UA not only increases cytoplasmic Ca2+ ions to amplify Ca2+ overload caused by CaCO3 decomposition, but also enhances Mn2+ ions-participated Fenton-like biocatalysis by intracellular H2 O2 generation and glutathione consumption. Then increasing the intracellular oxidative stress and decreasing the triphosadenine supply induce apoptosis together, resulting in UA-boosted IIT. The simple and efficient design of the dual ions reservoirs will contribute to improve the antitumor activity of IIT and further development of calcium-based nanomaterials in the future.

ZIF-8 Nanoparticles Evoke Pyroptosis for High-Efficiency Cancer Immunotherapy.

Although zeolitic imidazolate framework-8 (ZIF-8) has been applied in various tumor therapies, the intrinsic immunogenicity remains unclear. Here, we initiatively discover that ZIF-8 nanoparticles (NPs) can intrinsically induce pyroptosis by a caspase-1/gasdermin D (GSDMD)-dependent pathway. The pyroptotic cell death is accompanied by necrosis and immunogenic cell death (ICD) simultaneously for efficient in situ immunity initiation. Meanwhile, carbonyl cyanide m-chlorophenyl hydrazone (CCCP), a mitochondrial depolarizing agent, is successfully loaded into ZIF-8 NPs and found to further enhance the pyroptosis process. Collectively, the obtained Pluronic F127-modified CCCP-incorporated ZIF-8 NPs (F127 ZIF-8CCCP NPs) activate antitumor immunity and reprogram immunosuppressive tumor microenvironment (TME), realizing high-efficiency tumor growth inhibition. This work will facilitate biomedicine applications of ZIF-8 and provide good inspiration for pyroptosis-induced cancer therapy.

Sodium Bicarbonate Nanoparticles for Amplified Cancer Immunotherapy by Inducing Pyroptosis and Regulating Lactic Acid Metabolism.

Although immunotherapy has a broad clinical application prospect, it is still hindered by low immune responses and immunosuppressive tumor microenvironment. Herein, a simple and drug-free inorganic nanomaterial, alkalescent sodium bicarbonate nanoparticles (NaHCO3 NPs), is prepared via a fast microemulsion method for amplified cancer immunotherapy. The obtained alkalescent NaHCO3 regulates lactic acid metabolism through acid-base neutralization so as to reverse the mildly acidic immunosuppressive tumor environment. Additionally, it can further release high amounts of Na+ ions inside tumor cells and induce a surge in intracellular osmolarity, and thus activate the pyroptosis pathway and immunogenic cell death (ICD), release damage-associated molecular patterns (DAMPs) and inflammatory factors, and improve immune responses. Collectively, NaHCO3 NPs observably inhibit primary/distal tumor growth and tumor metastasis through acid neutralization remitted immunosuppression and pyroptosis induced immune activation, showing an enhanced antitumor immunity efficiency. This work provides a new paradigm for lactic acid metabolism and pyroptosis mediated tumor treatment, which has a potential for application in clinical tumor immunotherapy.

Hollow Aluminum Hydroxide Modified Silica Nanoadjuvants with Amplified Immunotherapy Effects through Immunogenic Cell Death Induction and Antigen Release.

In spite of the widespread application of vaccine adjuvants in various preventive vaccines at present, the existing adjuvants are still hindered by weak cellular immunity responses in therapeutic cancer vaccines. Herein, a hollow silica nanoadjuvant containing aluminum hydroxide spikes on the surface (SiAl) is synthesized for the co-loading of chemotherapeutic drug doxorubicin (Dox) and tumor fragment (TF) as tumor antigens (SiAl@Dox@TF). The obtained nanovaccines show significantly elevated anti-tumor immunity responses thanks to silica and aluminum-based composite nanoadjuvant-mediated tumor antigen release and Dox-induced immunogenic cell death (ICD). In addition, the highest frequencies of dendritic cells (DCs), CD4+ T cells, CD8+ T cells, and memory T cells as well as the best mice breast cancer (4T1) tumor growth inhibitory are also observed in SiAl@Dox@TF group, indicating favorable potential of SiAl nanoadjuvants for further applications. This work is believed to provide inspiration for the design of new-style nanoadjuvants and adjuvant-based cancer vaccines.

Tumor Microenvironment-Responsive Cu/CaCO3 -Based Nanoregulator for Mitochondrial Homeostasis Disruption-Enhanced Chemodynamic/Sonodynamic Therapy.

The efficiency of reactive oxygen species (ROS)-mediated cancer therapy is restrained by intrinsic characteristics in the tumor microenvironment (TME), such as overexpressed glutathione (GSH), hypoxia and limited efficiency of H2 O2 . In this work, intelligent copper-dropped calcium carbonate loading sonosensitizer Ce6 nanoparticles (Cu/CaCO3 @Ce6, CCC NPs) are established to realize TME-responsive self-supply of oxygen and successively Ca2+ -overloading-strengthened chemodynamic therapy/sonodynamic therapy (CDT/SDT). CCC NPs release Ca2+ , Cu2+ , and Ce6 in weakly acid and GSH-excessive TME. Released Cu2+ can not only consume GSH and turn into Cu+ via a redox reaction, but also provide CDT-creating hydroxyl radicals through the Fenton-like reaction. Under ultrasound irradiation, the intracellular oxidative stress is amplified profoundly relying on singlet oxygen outburst from SDT. Moreover, Ca2+ influx aggravates the mitochondrial disruption, which further accelerates the oxidation level. The facile and feasible design of the Cu-dropped CaCO3 -based nanoregulators will be further developed as a paradigm in ROS-contributed cancer therapy.

Flexible 2D Materials beyond Graphene: Synthesis, Properties, and Applications.

2D materials are now at the forefront of state-of-the-art nanotechnologies due to their fascinating properties and unique structures. As expected, low-cost, high-volume, and high-quality 2D materials play an important role in the applications of flexible devices. Although considerable progress has been achieved in the integration of a series of novel 2D materials beyond graphene into flexible devices, a lot remains to be known. At this stage of their development, the key issues concern how to make further improvements to high-performance and scalable-production. Herein, recent progress in the quest to improve the current state of the art for 2D materials beyond graphene is reviewed. Namely, the properties and synthesis techniques of 2D materials are first introduced. Then, both the advantages and challenges of these 2D materials for flexible devices are also highlighted. Finally, important directions for future advancements toward efficient, low-cost, and stable flexible devices are outlined.

Ultrasound-Augmented Mitochondrial Calcium Ion Overload by Calcium Nanomodulator to Induce Immunogenic Cell Death.

Immunogenic cell death (ICD), a manner of tumor cell death that can trigger antitumor immune responses, has received extensive attention as a potential synergistic modality for cancer immunotherapy. Although many calcium ion (Ca2+) nanomodulators have been developed for cancer therapy through mitochondrial Ca2+ overload, their ICD-inducing properties have not been explored. Herein, an acid-sensitive PEG-decorated calcium carbonate (CaCO3) nanoparticle incorporating curcumin (CUR; a Ca2+ enhancer) (PEGCaCUR) was prepared using a simple one-pot strategy. PEGCaCUR served as not only a Ca2+ nanomodulator inducing efficient mitochondrial Ca2+ overload but also an ICD inducer during improved synergistic cancer therapy. Combination of PEGCaCUR with ultrasound (US), PEGCaCUR+US, led to an enhanced ICD effect attributable to the enhanced mitochondrial Ca2+ overload, along with subsequent upregulation of reactive oxygen species levels. PEGCaCUR also facilitates photoacoustic/fluorescence dual-mode imaging, as well as effectively suppressing tumor growth and metastasis, indicating promising theranostic properties.

Biodegradable Upconversion Nanoparticles Induce Pyroptosis for Cancer Immunotherapy.

Pyroptosis, which is a mode of programmed cell death, has proven effective for cancer therapy. However, efficient pyroptosis inducers for tumor treatment are limited. This study proposes biodegradable K3ZrF7:Yb/Er upconversion nanoparticles (ZrNPs) as pyroptosis inducers for cancer immunotherapy. ZrNPs, which are similar to ion reservoirs, can be dissolved inside cancer cells and release high amounts of K+ and [ZrF7]3- ions, resulting a surge in intracellular osmolarity and homeostasis imbalance. This further induces an increase in reactive oxygen species (ROS), caspase-1 protein activation, gasdermin D (GSDMD) cleavage, and interleukin-1ß (IL-1ß) maturity, and results in cytolysis. In vivo tests confirm that ZrNPs-induced pyroptosis exhibits superior antitumor immunity activity confirmed by enhanced dendritic cells (DCs) maturity and frequency of effector-memory T cells, as well as observably inhibiting tumor growth and pulmonary metastasis. This work is believed to extend the biomedical applications of upconversion nanomaterials and deepen the understanding of intrinsic immunomodulatory activity of nanomaterials.

Biodegradable Ca2+ Nanomodulators Activate Pyroptosis through Mitochondrial Ca2+ Overload for Cancer Immunotherapy.

Pyroptosis provides a new direction and broad prospects for cancer immunotherapy. However, the development of a nanoplatform as a pyroptosis inducer is limited, and the discovery of a new type of nano-pyroptosis inducer for cancer immunotherapy is still imminent. Herein, biodegradable Ca2+ nanomodulators (CaNMs) are prepared as pyroptosis inducers for cancer immunotherapy via mitochondrial Ca2+ overload. The obtained CaNMs can decompose under low pH to release Ca2+ and curcumin, leading to a sudden surge in mitochondrial Ca2+ ions, eventually resulting in pyroptosis. We not only confirm the occurrence of mitochondrial Ca2+ overload-triggered pyroptosis for the first time but also reveal the robust immune responses via CaNMs, along with remarkably suppressing tumor proliferation and lung metastasis. This work will provide new strategies and inspiration for pyroptosis-mediated cancer treatments, greatly contributing to the further development of Ca2+ nanomodulators.

A Multifunctional Nanovaccine based on L-Arginine-Loaded Black Mesoporous Titania: Ultrasound-Triggered Synergistic Cancer Sonodynamic Therapy/Gas Therapy/Immunotherapy with Remarkably Enhanced Efficacy.

In order to achieve better antitumor therapeutic efficacy and inhibit tumor metastasis, a multifunctional nanovaccine based on L-arginine (LA)-loaded black mesoporous titania (BMT) is fabricated. In this system, LA is utilized as the exogenous NO supplementation for gas therapy, and BMT is served as acoustic sensitizer for sonodynamic therapy. The ultrasound (US) as the exogenous stimulus can simultaneously trigger BMT and LA to produce singlet oxygen (1 O2 ) and NO gas at tumor sites, respectively. Interestingly, 1 O2 from US-excited BMT can promote the oxidation of LA to produce more NO. The high concentration of 1 O2 and NO in cancer cell can cause intracellular strong oxidative stress level and DNA double-strand breaks to induce cancer cell apoptosis ultimately. The US-triggered BMT@LA "nanovaccine" combining with immune checkpoint inhibitor PD-L1 antibody (αPD-L1) can induce strong antitumor immune response thus effectively killing primary tumors and further inhibiting metastatic tumors. Hence, BMT@LA-based "nanovaccine" combining with αPD-L1 checkpoint blockade treatment can realize synergetic sonodynamic/gas/immunotherapy with enhanced antitumor therapeutic effects.

NIR-Triggered Multi-Mode Antitumor Therapy Based on Bi2 Se3 /Au Heterostructure with Enhanced Efficacy.

Of all the reaction oxygen species (ROS) therapeutic strategies, NIR light-induced photocatalytic therapy (PCT) based on semiconductor nanomaterials has attracted increasing attention. However, the photocatalysts suffer from rapid recombination of electron-hole pairs due to the narrow band gaps, which are greatly restricted in PCT application. Herein, Bi2 Se3 /Au heterostructured photocatalysts are fabricated to solve the problems by introducing Au nanoparticles (NPs) in situ on the surface of the hollow mesoporous structured Bi2 Se3 . Owing to the lower work function of Au NPs, the photo-induced electrons are easier to transfer and assemble on their surfaces, resulting in the increased separation of the electron-hole pairs with efficient ROS generation. Besides, Bi2 Se3 /Au heterostructures also enhance the photothermal efficiency due to the effective orbital overlaps with accelerated electron migrations according to density functional theory calculations. Moreover, the PLGA-PEG and the doxorubicin (DOX) are introduced for photothermal-triggered drug release in the system. The Bi2 Se3 /Au heterostructures also displays excellent infrared thermal (IRT) and computed tomography (CT) dual-modal imaging property for promising cancer diagnosis. Collectively, Bi2 Se3 /Au@PLGA-PEG-DOX exhibits prominent tumor inhibition effect based on synchronous PTT, PCT and chemotherapy triggered by NIR light for efficient antitumor treatment.