Rational Design of Biomaterials to Potentiate Cancer Thermal Therapy.

Cancer thermal therapy, also known as hyperthermia therapy, has long been exploited to eradicate mass lesions that are now defined as cancer. With the development of corresponding technologies and equipment, local hyperthermia therapies such as radiofrequency ablation, microwave ablation, and high-intensity focused ultrasound, have has been validated to effectively ablate tumors in modern clinical practice. However, they still face many shortcomings, including nonspecific damages to adjacent normal tissues and incomplete ablation particularly for large tumors, restricting their wide clinical usage. Attributed to their versatile physiochemical properties, biomaterials have been specially designed to potentiate local hyperthermia treatments according to their unique working principles. Meanwhile, biomaterial-based delivery systems are able to bridge hyperthermia therapies with other types of treatment strategies such as chemotherapy, radiotherapy and immunotherapy. Therefore, in this review, we discuss recent progress in the development of functional biomaterials to reinforce local hyperthermia by functioning as thermal sensitizers to endow more efficient tumor-localized thermal ablation and/or as delivery vehicles to synergize with other therapeutic modalities for combined cancer treatments. Thereafter, we provide a critical perspective on the further development of biomaterial-assisted local hyperthermia toward clinical applications.

Nonferrous Ferroptosis Inducer Manganese Molybdate Nanoparticles to Enhance Tumor Immunotherapy.

Tumor immunotherapy is an important tool in oncology treatment. However, only a small percentage of patients have an effective immune response to tumor immunotherapy due to the poor infiltration of pro-inflammatory immune cells in immune "cold" tumors and an immunosuppressive network in the tumor microenvironment (TME). Ferroptosis has been widely used as a novel strategy to enhance tumor immunotherapy. Herein, manganese molybdate nanoparticles (MnMoOx NPs) depleted the highly expressed glutathione (GSH) in tumors and inhibited glutathione peroxidase 4 (GPX4) expression, thus triggering ferroptosis, inducing immune cell death (ICD), further releasing damage-associated molecular patterns (DAMPs), and enhancing tumor immunotherapy. Furthermore, MnMoOx NPs can efficiently suppress tumors, promote the maturation of dendritic cells (DCs), infiltrate T cells, and reverse the immunosuppressive microenvironment, making the tumor an immune "hot" tumor. Combination with an immune checkpoint inhibitor (ICI) (α-PD-L1) further enhanced the anti-tumor effect and inhibited metastases as well. The work provides a new idea for the development of nonferrous inducers of ferroptosis to enhance cancer immunotherapy.

Magnetic Targeting Nanocarriers Combined with Focusing Ultrasound for Enhanced Intracerebral Hemorrhage Therapy.

Intracerebral hemorrhage (ICH) remains a significant cause of morbidity and mortality around the world, and surgery is still the most direct and effective way to remove ICH. However, the potential risks brought by surgery, such as normal brain tissue damage, post-operative infection, and difficulty in removing deep hematoma, are still the main problems in the surgical treatment of ICH. Activation of the peroxisome proliferator-activated receptor gamma (PPARγ) is reported to show a good therapeutic effect in hematoma clearance. Herein, a magnetic targeting nanocarrier loaded with a PPARγ agonist (15d-PGJ2-MNPs) is synthesized, which could be magnetically targeted and enriched in the area of the hematoma after intravenous injection. Subsequent application of focusing ultrasound (FUS) could enhance drug diffusion, which activates the PPARγ receptors on macrophages around the hematoma for better hematoma clearance. The 15d-PGJ2-MNP treatment alleviates brain injury, accelerates hematoma clearance, attenuates neuroinflammation, reduces brain edema and significantly improves the deficits in sensory and motor function and spatial learning ability in the ICH mouse model. This work proposes an effective magnetic targeting plus FUS method to treat ICH, highlighting its great potential in the treatment of hemorrhagic stroke.

Oxygen-Deficient Molybdenum Oxide Nanosensitizers for Ultrasound-Enhanced Cancer Metalloimmunotherapy.

Oxygen-deficient molybdenum oxide (MoOX ) nanomaterials are prepared as novel nanosensitizers and TME-stimulants for ultrasound (US)-enhanced cancer metalloimmunotherapy. After PEGylation, MoOX -PEG exhibits efficient capability for US-triggered reactive oxygen species (ROS) generation and glutathione (GSH) depletion. Under US irradiation, MoOX -PEG generates a massive amount of ROS to induce cancer cell damage and immunogenic cell death (ICD), which can effectively suppress tumor growth. More importantly, MoOX -PEG itself further stimulates the maturation of dendritic cells (DCs) and triggeres the activation of the cGAS-STING pathway to enhance the immunological effect. Due to the robust ICD induced by SDT and efficient DC maturation stimulated by MoOX -PEG, the combination treatment of MoOX -triggered SDT and aCTLA-4 further amplifies antitumor therapy, inhibits cancer metastases, and elicits robust immune responses to effectively defeat abscopal tumors.

HX V2 O5 Nanocatalysts Combined with Ultrasound for Triple Amplification of Oxidative Stress to Enhance Cancer Catalytic Therapy.

Multiple amplification of tumor oxidative stress has been demonstrated as efficient strategy to enhance the reactive oxygen species (ROS)-mediated cancer therapy. Herein, vanadium-based nanocatalysts, hydrogen vanadium bronzes (HX V2 O5 , for short HVO), were constructed and employed as novel biocatalysts for amplifying tumor oxidative stress and enhancing cancer catalytic therapy. Such HVO nanocatalysts harboring multivalent V element possessed multi-functional catalytic activity in decomposing H2 O2 into ⋅OH and depleting endogenous glutathione (GSH) to dually amplify tumor oxidative stress. Meanwhile, HVO nanocatalysts could also be activated by ultrasound to further triply amplify oxidative stress. The massive intracellular ROS caused mitochondrial dysfunction, DNA damage, cell cycle arrest, and cell proliferation inhibition, further realizing cancer cell death and tumor growth inhibition. Collectively, HVO nanocatalysts highlight the remarkable value of ROS-mediated cancer therapies.

Oxygen-Deficient Bimetallic Oxide FeWOX Nanosheets as Peroxidase-Like Nanozyme for Sensing Cancer via Photoacoustic Imaging.

Nanozymes with high catalytic activity and great stability have attracted increasing interests as the promising alternative to natural enzymes for applications in various fields. In this study, a new type of highly efficient peroxidase-like nanozymes based on FeWOX nanosheets (NSs) synthesized by a thermal-decomposition method is reported. Owing to the sheet-structure with maximized utilization of catalytic sites (Fe atoms and oxygen vacancies), such FeWOX NSs exert efficient enzyme activity to trigger catalytic decomposition of hydrogen peroxide (H2 O2 ) into hydroxyl radicals (•OH). A nanozyme-based ratio-metric nanoprobe is then fabricated by co-loading of 3,3,5,5-tetramethylbenzidine (TMB) and IR780 dye on FeWOX NSs to enable ratio-metric photoacoustic (PA) imaging of endogenous H2 O2 , as verified by imaging of the subcutaneous 4T1 xenograft tumor model and lipopolysaccharide (LPS)-induced inflammation model. Moreover, FeWOX NSs could also be employed as promising nanoagents for multimodal computed tomography (CT) and magnetic resonance (MR) imaging of tumors, due to the strong X-ray attenuation ability of W element and high MR contrast ability of Fe element, respectively. Importantly, FeWOX NSs with good biodegradability could be cleared out from the body without any significant biotoxicity. This work highlights bimetallic oxide FeWOX NSs as an enzyme-mimetic nanoplatform for imaging of the tumor microenvironment.

Bimetallic Oxide MnMoOX Nanorods for in Vivo Photoacoustic Imaging of GSH and Tumor-Specific Photothermal Therapy.

Accurate imaging of glutathione (GSH) in vivo is able to provide real-time visualization of physiological and pathological conditions. Herein, we successfully synthesize bimetallic oxide MnMoOX nanorods as an intelligent nanoprobe for in vivo GSH detection via photoacoustic (PA) imaging. The obtained MnMoOX nanoprobe with no near-infrared (NIR) absorption in the absence of GSH would exhibit strong GSH-responsive NIR absorbance, endowing PA imaging detection of GSH. Due to the up-regulated GSH concentration in the tumor microenvironment, our MnMoOX nanoprobe could be utilized for in vivo tumor-specific PA imaging. Moreover, MnMoOX nanorods with GSH-responsive NIR absorbance could also be employed to achieve tumor-specific photothermal therapy (PTT). Importantly, such MnMoOX nanorods show inherent biodegradability and could be rapidly cleared out from the body, minimizing their long-term body retention and potential toxicity. Our work presents a new type of GSH-responsive nanoprobe based on bimetallic oxide nanostructures, promising for tumor-specific imaging and therapy.

Magnesium implants with alternating magnetic field-enhanced hydrogen release and proton depletion for anti-infection treatment and tissue repair.

Implant-related osteomyelitis is a formidable hurdle in the clinical setting and is characterized by inflammation, infection, and consequential bone destruction. Therefore, effective reactive oxygen species (ROS) scavenging, bacterial killing, and subsequent bone tissue repair are urgently needed for the treatment of difficult-to-heal osteomyelitis. Herein, we utilized the eddy-thermal effect of magnesium (Mg) implants under an alternating magnetic field (AMF) for the controlled release of H2 gas and ions (OH- and Mg2+) for the treatment of osteomyelitis. H2 released by Mg rods under AMFs effectively scavenged cytotoxic ROS, exhibiting anti-inflammatory effects and consequently disrupting the environment of bacterial infections. In addition, the OH- hindered the energy metabolism of bacteria by effectively neutralizing protons within the microenvironment. Moreover, H2 impaired the permeability of bacterial membranes and expedited the damage induced by OH-. This synergistic AMF-induced H2 and proton depletion treatment approach not only killed both gram-negative and gram-positive bacteria but also effectively treated bacterial infections (abscesses and osteomyelitis). Moreover, Mg2+ released from the Mg rods enhanced and accelerated the process of bone osteogenesis. Overall, our work cleverly exploited the eddy-thermal effect and chemical activity of Mg implants under AMFs, aiming to eliminate the inflammatory environment and combat bacterial infections by the simultaneous release of H2, OH-, and Mg2+, thereby facilitating tissue regeneration. This therapeutic strategy achieved multiple benefits in one, thus presenting a promising avenue for clinical application.

Oncolytic mineralized bacteria as potent locally administered immunotherapeutics.

Oncolytic bacteria can trigger innate immune activity. However, the antitumour efficacy of inactivated bacteria is poor, and attenuated live bacteria pose substantial safety risks. Here we show that intratumourally injected paraformaldehyde-fixed bacteria coated with manganese dioxide potently activate innate immune activity, modulate the immunosuppressive tumour microenvironment and trigger tumour-specific immune responses and abscopal antitumour responses. A single intratumoural administration of mineralized Salmonella typhimurium suppressed the growth of multiple types of subcutaneous and orthotopic tumours in mice, rabbits and tree shrews and protected the cured animals against tumour rechallenge. We also show that mineralized bacteria can be administered via arterial embolization to treat orthotopic liver cancer in rabbits. Our findings support the further translational testing of oncolytic mineralized bacteria as potent and safe antitumour immunotherapeutics.

Liquid metal microspheres with an eddy-thermal effect for magnetic hyperthermia-enhanced cancer embolization-immunotherapy.

Patients with hepatocellular carcinoma (HCC) display poor prognosis because HCC involves a high rate of metastasis and regrowth. Herein, we present an effective strategy to treat HCC using magnetic hyperthermia therapy (MHT)-enhanced cancer immunotherapy combined with transcatheter arterial embolization (TAE). Uniform liquid metal microspheres (LM MSs) obtained by microfluidic technology with powerful eddy-thermal effects could be used as both MHT and TAE agents for effective cancer therapy. The eddy-thermal effect of LM MSs demonstrated effective MHT, whereas LM MS-induced MHT boosted the immune system, promoted immune cell infiltration, and further stimulated powerful immune responses to suppress the growth of distant tumors, together with immune checkpoint blockade therapy. Furthermore, LM MS-lipiodol dispersion displayed excellent efficacy of the combined MHT-TAE in the orthotopic rabbit liver cancer model. Our work not only highlighted that LM MSs could act as effective MHT agents to achieve MHT-enhanced immunotherapy but also presented the significant promise of combining MHT with TAE for the efficient treatment of large orthotopic liver tumors.

Bioactive Vanadium Disulfide Nanostructure with "Dual" Antitumor Effects of Vanadate and Gas for Immune-Checkpoint Blockade-Enhanced Cancer Immunotherapy.

Bioactive inorganic nanomaterials and the biological effects of metal ions have attracted extensive attention in tumor therapy in recent years. Vanadium (V), as a typical bioactive metal element, regulates a variety of biological functions. However, its role in antitumor therapy remains to be revealed. Herein, biodegradable vanadium disulfide (VS2) nanosheets (NSs) were prepared as a responsive gas donor and bioactive V source for activating cancer immunotherapy in combination with immune-checkpoint blockade therapy. After PEGylation, VS2-PEG exhibited efficient glutathione (GSH) depletion and GSH-activated hydrogen sulfide (H2S) release. Exogenous H2S caused lysosome escape and reduced adenosine triphosphate (ATP) synthesis in tumor cells by interfering with the mitochondrial membrane potential and inducing acidosis. In addition, VS2-PEG degraded into high-valent vanadate, leading to Na+/K+ ATPase inhibition, potassium efflux, and interleukin (IL)-1ß production. Together with further induction of ferroptosis and immunogenic cell death, a strong antitumor immune response was stimulated by reversing the immunosuppressive tumor microenvironment. Moreover, the combined treatment of VS2-PEG and α-PD-1 amplified antitumor therapy, significantly suppressed tumor growth, and further elicited robust immunity to effectively defeat tumors. This work highlights the biological effects of vanadium for application in cancer treatment.

Calcium Hydride-Based Dressing to Promote Wound Healing.

Wound microenvironment with excess reactive oxygen species (ROS) can significantly inhibit wound healing. Encouraged by hydrogen molecules (H2 ) with effective ROS scavenging and calcium hydride (CaH2 ) with sufficient H2 supply, the authors for the first time employed CaH2 as a therapeutic H2 donor and starch as a diluent to construct CaH2 pulvis dressing for wound healing treatment. It has been found that CaH2 by generating H2 exhibited excellent ROS scavenging performance, favorable for preserving the oxidative-stress-induced cell death. After being applied onto the skin wound, the CaH2 pulvis dressing with the unique ROS-scavenging ability can accelerate skin wound healing in healthy/diabetic mice (small animal models) and Bama mini-pigs (large animal model). Such CaH2 dressing can release H2 to relieve the inflammation levels, decrease the secretion of pro-inflammatory cytokines, increase the infiltration of inflammation-suppressive immune cells, and promote the regeneration of new blood vessels and collagens, thereby accelerating wound healing. This work highlighted that the integration of anti-oxidation and anti-inflammation functions based on CaH2 dressing endowed it with a promising possibility for the treatment of inflammatory diseases.

Thymopentin ameliorates experimental colitis via inhibiting neutrophil extracellular traps.

BACKGROUND: The long-term prognosis of Crohn's disease (CD) remains unsatisfactory. Therefore, we assessed the therapeutic effect of thymopentin (TP5) in a mouse model of 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis, which mimics CD, and analyzed its impact on neutrophil extracellular traps (NETs). METHODS: NET markers, including myeloperoxidase (MPO), neutrophil elastase (NE), citrullinated histone H3 (CitH3), peptidyl arginine deiminase IV (PAD4), and double-stranded DNA (dsDNA) were assessed by immunostaining and enzyme-linked immunosorbent assay. NET formation was evaluated in vitro. Neoseptin 3, a specific NET agonist, was used to reverse the effect of TP5 on TNBS-induced colitis. The action mechanism of TP5 was investigated using RNA-seq. RESULTS: TP5 ameliorated weight loss (P < 0.001), disease activity index (DAI) (P = 0.05), colon shrinkage (P = 0.04), and elevated levels of tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1ß, IL-6, and neutrophils in the TNBS group. The TNBS group exhibited increased MPO, NE, CitH3, PAD4, dsDNA and MPO-DNA levels (all P < 0.001), which decreased after TP5 administration (P = 0.01, P < 0.001, P < 0.001, P < 0.001, P = 0.02, and P = 0.02 respectively). Tissue CitH3 levels were positively correlated with DAI and TNF-α levels (P < 0.05). Furthermore, phorbol 12-myristate 13-acetate-stimulated NET formation increased by 1.8-, 2.8-, and 2.3-fold in vitro in the control, TNBS + saline, and TNBS + TP5 groups, respectively. Neoseptin 3 significantly reversed the effect of TP5. RNA-seq revealed potential pathways underlying the effect of TP5. CONCLUSION: TP5 effectively ameliorated colitis by suppressing NETs in the experimental CD model.

The combination of eddy thermal effect of biodegradable magnesium with immune checkpoint blockade shows enhanced efficacy against osteosarcoma.

Osteosarcoma (OS) patients have a poor prognosis due to its high degree of heterogeneity and high rate of metastasis. Magnetic hyperthermia therapy (MHT) combined with immunotherapy is an effective strategy to treat solid and metastatic tumors. Here, we combined biodegradable magnesium (Mg) macroscale rods, which acted as an eddy thermo-magnetic agent under a low external alternating magnetic field, and immunotherapy to achieve a radical cure for OS. The eddy thermal effect (ETE) of the Mg rods (MgR) showed outstanding cytotoxic effects and enhanced the maturation of dendritic cells (DCs), and the mild MHT induced the immunogenic cell death (ICD) in the OS cells. Combined with immune checkpoint blockade (ICB) therapy, we obtained an excellent curative effect against OS, and a further evaluation demonstrated that the local MHT induced by the MgR increased T cells infiltration and the polarization of M1 macrophages. Interestingly, the biodegradable MgR also promoted bone osteogenesis. Our work highlighted the uneven ETE mediated by the biodegradable MgR induced a comprehensive immunologic activation in the OS tumor microenvironment (TME), which would inspire the application of MHT for the effective treatment of OS.

Oral Delivery of Therapeutic Antibodies with a Transmucosal Polymeric Carrier.

Therapeutic proteins are playing increasingly important roles in treating numerous types of diseases. However, oral administration of proteins, especially large ones (e.g., antibodies), remains a great challenge due to their difficulties in penetrating intestinal barriers. Herein, fluorocarbon-modified chitosan (FCS) is developed for efficient oral delivery of different therapeutic proteins, in particular large ones such as immune checkpoint blockade antibodies. In our design, therapeutic proteins are mixed with FCS to form nanoparticles, lyophilized with appropriate excipients, and then filled into enteric capsules for oral administration. It has been found that FCS could promote transmucosal delivery of its cargo protein via inducing transitory rearrangement of tight junction associated proteins between intestinal epithelial cells and subsequently release free proteins into blood circulation. It is shown that at a 5-fold dose oral delivery of anti-programmed cell death protein-1 (αPD1) or its combination with anti-cytotoxic T-lymphocyte antigen 4 (αCTLA4) using this method could achieve comparable antitumor therapeutic responses to that achieved by intravenous injection of corresponding free antibodies in various types of tumor models and, more excitingly, result in significantly reduced immune-related adverse events. Our work successfully demonstrates the enhanced oral delivery of antibody drugs to achieve systemic therapeutic responses and may revolutionize the future clinical usage of protein therapeutics.

Association of Neutrophil Extracellular Traps with Fistula Healing in Patients with Complex Perianal Fistulizing Crohn's Disease.

BACKGROUND AND AIMS: Perianal fistulizing Crohn's disease [pfCD] is a disabling phenotype of Crohn's disease [CD] with suboptimal outcomes. We assessed neutrophil extracellular traps [NETs] in perianal fistulas and implicated their roles in pfCD healing. METHODS: Patients with complex pfCD who developed preplaced seton drainage were recruited during the verified maintenance of remission in CD. Fistula tracts were sampled during definitive surgery plus seton removal. Patient demographics, CD classification, medication strategy and healing of pfCD were recorded. RNA sequencing was applied for transcriptomic profile analysis. NET components, including myeloperoxidase [MPO], neutrophil elastase [NE] and citrullinated histone H3 [CitH3], were identified using immunofluorescence. Serum infliximab [IFX], anti-IFX antibodies, and tissue levels of IFX, adalimumab [ADA], MPO and CitH3 were determined using enzyme-linked immunosorbent assays. Peptidyl arginine deiminase IV [PAD4], tumour necrosis factor [TNF]-α, and NE were detected using immunohistochemistry. Gene expression levels of PAD family members were assessed with quantitative PCR. RESULTS: Twenty-one patients were included, 15 of whom adopted IFX as maintenance treatment. RNA-sequencing revealed differences in neutrophil associated pathways between unhealed and healed fistulas. NET components [MPO/NE/CitH3] were detectable in the fistulas and were parallel with the levels of PAD4. Eleven of 21 [52%] patients experienced complete healing of the pfCD 108 weeks post-operatively. Fistula NETs were significantly increased in patients with unhealed pfCD. Increased NETs were associated with abundant TNF-α production and the absence of IFX in fistulas. CONCLUSIONS: NETs exist in pfCD fistulas, which are associated with unhealed post-operative fistulas in pfCD, suggesting their prognostic roles in pfCD.

Recent advances in upconversion nanoparticle-based nanocomposites for gas therapy.

Gas therapy has attracted wide attention for the treatment of various diseases. However, a controlled gas release is highly important for biomedical applications. Upconversion nanoparticles (UCNPs) can precisely convert the long wavelength of light to ultraviolet/visible (UV/Vis) light in gas therapy for the controlled gas release owing to their unique upconversion luminescence (UCL) ability. In this review, we mainly summarized the recent progress of UCNP-based nanocomposites in gas therapy. The gases NO, O2, H2, H2S, SO2, and CO play an essential role in the physiological and pathological processes. The UCNP-based gas therapy holds great promise in cancer therapy, bacterial therapy, anti-inflammation, neuromodulation, and so on. Furthermore, the limitations and prospects of UCNP-based nanocomposites for gas therapy are also discussed.

Magnesium galvanic cells produce hydrogen and modulate the tumor microenvironment to inhibit cancer growth.

Hydrogen can be used as an anti-cancer treatment. However, the continuous generation of H2 molecules within the tumor is challenging. Magnesium (Mg) and its alloys have been extensively used in the clinic as implantable metals. Here we develop, by decorating platinum on the surface of Mg rods, a Mg-based galvanic cell (MgG), which allows the continuous generation of H2 in an aqueous environment due to galvanic-cell-accelerated water etching of Mg. By implanting MgG rods into a tumor, H2 molecules can be generated within the tumor, which induces mitochondrial dysfunction and intracellular redox homeostasis destruction. Meanwhile, the Mg(OH)2 residue can neutralize the acidic tumor microenvironment (TME). Such MgG rods with the micro-galvanic cell structure enable hydrogen therapy to inhibit the growth of tumors, including murine tumor models, patient-derived xenografts (PDX), as well as VX2 tumors in rabbits. Our research suggests that the galvanic cells for hydrogen therapy based on implantable metals may be a safe and effective cancer treatment.

Oxygen-Deficient Tungsten Oxide (WOx) Nanobelts with pH-Sensitive Degradation for Enhanced Sonodynamic Therapy of Cancer.

The further bioapplications of sonodynamic therapy (SDT) were hindered by the inadequate efficiency and poor degradability of sonosensitizers and the hypoxic tumor microenvironment (TME). Therefore, it is ideal to develop pH-sensitive sonosensitizers that generate abundant reactive oxygen species (ROS) and rapidly degrade in a neutral environment while slowly degrading in an acidic environment to reduce their long-term toxicity. Herein, the defective tungsten oxide nanobelts (WOx NBs) were developed as a type of pH-sensitive and biodegradable sonosensitizers with a high SDT efficiency and low toxicity for enhanced SDT. The defective oxygen sites of WOx NBs could inhibit the recombination of electrons and holes, making WOx NBs promising sonosensitizers that could generate abundant ROS under ultrasound (US) irradiation. Enhanced by the catalase (CAT) that reacted with H2O2 to generate O2, the WOx NBs exhibited better SDT performance against 4T1 cells in both normoxic and hypoxic environments. In addition, the WOx NBs could degrade by releasing protons (H+), resulting in intracellular acidification and inhibited cell motility that further enhanced the therapeutic effects of SDT. Assisted with CAT and ALG for hypoxia refinement and better retention, the WOx NBs enabled effective SDT and antimetastasis against 4T1 tumors in vivo. Most importantly, the WOx NBs could degrade rapidly in normal tissues but slowly in an acidic TME, which was favorable for their fast clearance, without any obvious long-term toxicity. Our work developed defective WOx NBs with a high SDT efficiency and pH-sensitive degradation for enhanced SDT, which extended the biomedical application of tungsten-based nanomaterials and the further development of SDT.

Orally administered titanium carbide nanosheets as anti-inflammatory therapy for colitis.

Rationale: Oxidative stress, resulting from excessive reactive oxygen species (ROS), plays an important role in the initiation and progression of inflammatory bowel disease (IBD). Therefore, developing novel strategies to target the disease location and treat inflammation is urgently needed. Methods: Herein, we designed and developed a novel and effective antioxidant orally-administered nanoplatform based on simulated gastric fluid (SGF)-stabilized titanium carbide MXene nanosheets (Ti3C2 NSs) with excellent biosafety and multiple ROS-scavenging abilities for IBD therapy. Results: This broad-spectrum and efficient ROS scavenging performance was mainly relied on the strong reducibility of Ti-C bound. Intracellular ROS levels confirmed that Ti3C2 NSs could efficiently eliminate excess ROS against oxidative stress-induced cell damage. Following oral administration, negatively-charged Ti3C2 NSs specifically adsorbed onto the positively-charged inflamed colon tissue via electrostatic interaction, leading to efficient therapy of dextran sulfate sodium salt (DSS)-induced colitis. The therapeutic mechanism mainly attributed to decreased ROS levels and pro-inflammatory cytokine secretion, and increased M2-phenotype macrophage infiltration and anti-inflammatory cytokine secretion, efficiently inhibiting inflammation and alleviating colitis symptoms. Due to their excellent ROS-scavenging performance, Ti3C2-based woundplast also promoted skin wound healing and functional vessel formation. Conclusions: Our study introduces redox-mediated antioxidant MXene nanoplatform as a novel type of orally administered nanoagents for treating IBD and other inflammatory diseases of the digestive tract.