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

Topology-Sensitive Spin-Selecting Super-Exchange Interactions at Half-Antiperovskites with Orderly-Oxidized Semimetals for Acidic Water Oxidation

Developing inexpensive catalysts for acidic water oxidation plays a critical role in energy conversions and storages, but which have to trade off their catalytic activity and electrochemical stability. Different from traditional nano-engineering, herein we focus onto manipulating the spin-dependent topological quantum interactions to facilitate acidic water splitting at half-antiperovskite (Ni2Co1In2S2) with orderly-oxidized Kagome lattices, in which spatial wave functions of the triangular metal units (M3) are spontaneously converted to the anti-symmetry feature due to the symmetry breaking from controllable bridged-oxygen decorations (M3O), leading to a spin-selecting-dependent electronic reconfiguration. This topology-sensitive symmetry breaking makes the super-exchange interactions among neighboring metal sites switch to the indirect out-plane configuration (M─O─M) from the direct in-plane form (M─M), meanwhile the spin-dependent transformation from antiferromagnetic states to ferromagnetic states causes these metal sites to demonstrate a semi-metallic property for optimizing their bonding interactions with reactants. As a result, the capacity of carrier migration and intermediate diffusion in the inner Helmholtz region is significantly improved, which makes mass activity increase to 20.5 A g-1 at an overpotential of ≈356 mV, demonstrating an obvious superiority over the other state-of-the-art catalysts without noble metals. This work provides a new insight for designing topology-dependent catalysts to better understand spin-related reaction kinetics.

Pickering emulsion with tumor vascular destruction and microenvironment modulation for transarterial embolization therapy

In the clinic, Lipiodol chemotherapeutic emulsions remain a main choice for patients diagnosed with hepatocellular carcinoma (HCC) via the mini-invasive transarterial chemoembolization (TACE) therapy. However, the poor stability of conventional Lipiodol chemotherapeutic emulsions would result in the fast drug diffusion and incomplete embolization, inducing systemic toxicity and impairing the efficacy of TACE therapy. Therefore, it is of great importance to construct alternative formulations based on commercial Lipiodol to achieve the improved efficacy and safety of HCC treatment. Herein, calcium phosphate (CaP) nanoparticles-stabilized Lipiodol Pickering emulsion (CaP-LPE) with improved stability and pH-responsiveness is prepared and utilized for the encapsulation of combretastatin A4-phosphate (CA4P), a clinically approved vascular disrupting agent. The obtained CA4P-loaded CaP-LPE (CCaP-LPE) was shown to be enhanced stability compared to conventional Lipiodol emulsion and pH-responsive release of the encapsulated drugs. On one hand, the released CA4P could disrupt tumor vascular and cut off the blood supplying of tumor cells, thus starving cancer cells. Moreover, it was revealed that CCaP-LPE could reverse immunosuppressive tumor microenvironment (TME) by neutralizing tumor acidity, leading to the increased infiltration of CD8+ T cells and the decreased percentages of immunosuppressive cells. As the result, such CCaP-LPE could effectively shrink orthotopic N1S1 HCC tumors in rats by eliciting a potent antitumor immune response. Therefore, this study highlights a simple strategy to construct a novel LPE with the potencies of tumor vascular disruption and TME modulation, holding a great promise for TAE therapy of HCC.

Precision neuroregulation combining liquid metal and magnetic stimulation

BACKGROUND

Electromagnetic field-based neuroregulation technology is a crucial technique for treating central nervous system and peripheral nervous system disorders. However, the use of invasive electrodes has unavoidable problems such as the risk of inflammation due to high hardness, electrical connections and the need for batteries. On the other hand, non-invasive magnetic stimulation has limitations such as centimeter-level focal areas and shallow stimulation depth.

METHODS

To enhance the precision and effectiveness of wireless magnetic stimulation, we employed a figure-8 magnetic stimulation coil (8-coil) to generate a magnetic field, combined with an injectable, highly conductive, and flexible liquid metal (LM) to produce a millimeter-scale focused electric field. A coaxial electric field measurement electrode was used to establish an agar phantom-based electric field measurement platform. The sciatic nerve of C57 mice was stimulated under acute anesthesia conditions, and electromyography (EMG) signals were collected to evaluate the enhancement of stimulation effects. Long-term safety was assessed through four weeks of implantation.

RESULTS

Theoretical analysis and finite element simulations demonstrated that the combination of LM and the 8-coil generated a millimeter-scale enhanced vector electric field within the tissue. Measured electric field distributions closely aligned with theoretical and simulation results. In the sciatic nerve experiments on mice, 1 µL of LM under a 0.45 T magnetic field significantly increased EMG signals and leg movement amplitude by approximately 500%. Long-term implantation under magnetic stimulation revealed no adverse effects.

CONCLUSIONS

This method utilizes focused electric fields to improve the precision and effectiveness of neuro-magnetic stimulation. It holds promise as a novel approach for precise stimulation. Preliminary evidence was provided for the safety of in vivo LM implantation under external magnetic fields.

Next‐Generation Flexible Embolic Systems: Targeted Transarterial Chemoembolization Strategies for Hepatocellular Carcinoma

Transarterial chemoembolization (TACE) remains the gold standard for treating intermediate‐stage hepatocellular carcinoma (HCC), yet faces great challenges in overcoming tumor heterogeneity, hypoxia‐induced angiogenesis, and metastatic progression. The development of advanced flexible embolization materials marks a revolutionary leap in interventional therapy, offering opportunities to revolutionize embolization precision, drug delivery kinetics, and tumor microenvironment modulation. This comprehensive review systematically examines the paradigm shift toward next‐generation TACE technology, emphasizing the limitations of conventional approaches and innovations in flexible embolic agents. A detailed discussion of next‐generation nano‐flexible embolic systems is presented, emphasizing their unique coagulation dynamics, real‐time imaging capabilities, and therapeutic precision. The review delves into groundbreaking TACE strategies integrating hypoxia modulation, energy conversion therapeutics, and sophisticated tumor microenvironment engineering. Clinical translation aspects are thoroughly explored, including large‐scale trial outcomes, vascular recanalization dynamics, and patient‐specific treatment optimization. Looking forward, key frontiers in the field is identified: intelligent nanocomposite systems, synergistic combination therapies, and precision medicine approaches tailored to individual tumor biology. This work not only objectively evaluates current progress but also charts future research priorities, aiming to transform TACE from a palliative intervention to a precision medicine platform and ultimately reshaping the landscape of HCC treatment and patient care.

Advancements in the application of ablative therapy and its combination with immunotherapy in anti-cancer therapy

Cancer is a significant health issue impacting humans. Currently, systemic therapies such as chemotherapy have significantly increased the life expectancy of cancer patients. However, some patients are unable to endure systemic treatment due to its significant adverse effects, leading to an increased focus on local therapies including radiation and ablation therapy. Ablation therapy is a precise, low-toxicity, and minimally invasive localized therapy that is increasingly acknowledged by clinicians and cancer patients. Many cancer patients have benefited from it, with some achieving full recovery. Currently, numerous studies have shown that ablation therapy is effective due to its ability to kill cancer cells efficiently and activate the body's anti-cancer immunity. It can also convert "cold cancers" into "hot cancers" and enhance the effectiveness of immunotherapy when used in combination. In this article, we categorize ablation therapy into thermal ablation, cryoablation, photodynamic therapy (PDT), irreversible electroporation (IRE), etc. Thermal ablation is further divided into Radiofrequency ablation (RFA), microwave ablation (WMA), high-frequency focused ultrasound (HIFU), photothermal therapy (PTT), magnetic heat therapy (MHT), etc. We systematically review the most recent advancements in these ablation therapies that are either currently used in clinic or are anticipated to be used in clinic. Then, we also review the latest development of various ablative therapies combined with immunotherapy, and its future development. CLINICAL RELEVANCE STATEMENT: Ablation therapy, an invasive localized treatment, offers an alternative to systemic therapies for cancer patients who cannot tolerate their adverse effects. Its ability to kill cancer cells efficiently and activate anti-cancer immunity. This article reviews recent advancements in ablation therapies, including thermal, cryoablation, PDT, and IRE, and their potential clinical applications, both standalone and in combination with immunotherapy.

Magnetic Micro/nanorobots in Cancer Theranostics: From Designed Fabrication to Diverse Applications

Cancer poses a substantial threat and a serious challenge to public human health, driving the promotion of sophisticated technologies for cancer therapy. While conventional chemotherapy has bottlenecks such as low delivery efficiency, strong toxic side effects, and tumor enrichment barriers, magnetic micro/nanorobots (MNRs) emerge as promising therapeutic candidates that provide alternative strategies for cancer therapy. MNR is a kind of human-made machine that is micro- or nanosized, is reasonably designed, and performs command tasks through self-actuated or externally controlled propulsion mechanisms, which can be potentially applied in cancer theranostics. Here, this review first introduces the components that constitute a typical magnetic MNR, including the body part, the driving part, the control part, the function part, and the sensing part. Subsequently, this review elucidates representative fabrication methods to construct magnetic MNRs from top-down approaches to bottom-up approaches, covering injection molding, self-rolling, melt electrospinning writing, deposition, biotemplate method, lithography, assembling, 3D printing, and chemical synthesis. Furthermore, this review focuses on multiple applications of magnetic MNRs facing cancer diagnosis and treatment, encompassing imaging, quantification, drug release, synergy with typical therapies, cell manipulation, and surgical assistance. Then, this review systematically elaborates on the biocompatibility and biosafety of magnetic MNRs. Finally, the challenges faced by magnetic MNRs are discussed alongside future research directions. This review is intended to provide scientific guidance that may improve the comprehension and cognition of cancer theranostics through the platform of magnetic MNRs, promoting and prospering the practical application development of magnetic MNRs.

Lignocellulose-Mediated Functionalization of Liquid Metals toward the Frontiers of Multifunctional Materials

Lignocellulose-mediated liquid metal (LM) composites, as emerging functional materials, show tremendous potential for a variety of applications. The abundant hydroxyl, carboxyl, and other polar groups in lignocellulose facilitate the formation of strong chemical bonds with LM surfaces, enhancing wettability and adhesion for improved interface compatibility. Beyond serving as a supportive matrix, lignocellulose can be tailored to optimize the microstructure of the composites, adapting them for diverse applications. This review comprehensively summarizes the fundamental principles and recent advancements in lignocellulose-mediated LM composites, highlighting the advantages of lignocellulose in composite fabrication, including facile synthesis, versatile interactions, and inherent functionalities. Key modulation strategies for LMs and innovative synthesis methods for functionalized lignocellulose composites are discussed. Furthermore, the roles and structure-performance relationships of these composites in electromagnetic shielding, flexible sensors, and energy storage devices are systematically summarized. Finally, the obstacles and prospective advancements pertaining to lignocellulose-mediated LM composites are thoroughly scrutinized and deliberated upon. This review is expected to provide basic guidance for researchers to boost the popularity of LMs in diverse applications and provide useful references for design strategies of state-of-the-art LMs.

Minimalistic Implant for Percutaneous Magnetic Hyperthermia-Based Combination Therapy of Hepatocellular Carcinoma

Percutaneous local thermal therapy, containing radio frequency and microwave ablation, is widely utilized in the clinical management of hepatocellular carcinoma (HCC) due to its minimal invasiveness and favorable therapeutic outcomes. However, its further development is limited by a prolonged ablation duration and the risk of excessive heating. Magnetic hyperthermia therapy (MHT) provides a new perspective for percutaneous tumor thermal ablation due to its superior tissue penetration capability and safety. Herein, an iron foam-agarose gel-drug (IF-Aga-drug) implant is prepared using a minimalistic method for percutaneous combination therapy of HCC. The excellent conductivity of IF endows it with strong heating capability owing to eddy current loss in an alternating magnetic field (AMF), while the abundant pores provide ample space for drug loading. Agarose gel imparts the IF platform with universal and efficient drug-loading capacity and controlled drug-release capability that is responsive to magnetic hyperthermia. Doxorubicin (DOX) is utilized as a representative drug to construct the IF-Aga-DOX implant, which is successfully employed in ultrasound-guided, magnetic hyperthermia-based combination chemotherapy for orthotopic HCC in rabbits under ultralow-power magnetic field intensities (Happl·fappl = 2.25 × 108 A m-1 s-1). The developed IF-Aga-drug implant platform offers a convenient and versatile strategy for percutaneous tumor therapy.

An electrically activable nanochip to intensify gas-ionic-immunotherapy

Excess intracellular H2S induces destructive mitochondrial toxicity, while overload of Zn2+ results in cell pyroptosis and potentiates the tumor immunogenicity for immunotherapy. However, the precise delivery of both therapeutics remains a great challenge. Herein, an electrically activable ZnS nanochip for the controlled release of H2S and Zn2+ was developed for enhanced gas-ionic-immunotherapy (GIIT). Under an electric field, a locality with particularly high concentrations of H2S and Zn2+ was established by the voltage-controlled degradation of the ZnS nanoparticles (NPs). Consequently, the ZnS nanochip-mediated gas-ionic therapy (GIT) resulted in mitochondrial membrane potential depolarization, energy generation inhibition, and oxidative stress imbalance in tumor cells. Interestingly, the cyclic guanosine monophosphate-adenosine monophosphate synthase-stimulator of interferon genes (cGAS-STING) signaling pathway was activated due to the mitochondrial destruction. Moreover, the released Zn2+ resulted in the increase of the intracellular Zn levels and cell pyroptosis, which enhanced the immunogenicity via the release of damage-associated molecular patterns (DAMPs). In vitro and in vivo studies revealed that the ZnS nanochip-based GIT effectively eliminated the tumors under an electric field and mobilized the cytotoxic T lymphocytes for immunotherapy. The combination with αCTLA-4 further promoted the adaptive immune response and inhibited tumor metastasis and long-term tumor recurrence. This work presented an electrically activable ZnS nanochip for combined immunotherapy, which might inspire the development of electric stimulation therapy.

Ultrasound-Activated Precise Sono-Immunotherapy for Breast Cancer with Reduced Pulmonary Fibrosis

Immune checkpoint inhibitors have demonstrated remarkable efficacy across various cancer types. However, immune-related adverse events (irAEs) pose a significant challenge in immunotherapy, particularly the associated pneumonia as the primary adverse reaction, which can lead to irreversible pulmonary fibrosis. Additionally, monotherapy with programmed death ligand (PD-L1) inhibitors has shown limited effectiveness. Therefore, to improve the response rate of immunotherapy and reduce pulmonary fibrosis, this study designed and prepared an intelligent nanodrug based on dendritic mesoporous silica nanoparticles (DMSNs) loaded with a sono-sensitive agent protoporphyrin IX (PpIX). Additionally, a reactive oxygen species (ROS) sensitive linker is used to attach the immunotherapeutic drug PD-L1 inhibitor (aPD-L1) to DMSNs via covalent bonds. The external ultrasound (US) activates PpIX to generate ROS, which breaks the linker to release aPD-L1 to induce sonodynamic therapy (SDT) and immunotherapy. This sono-immnotherapy approach demonstrated excellent outcomes in tumor inhibition, eliciting immune responses, and reducing pulmonary fibrosis. Overall, this study offers a new, efficient, and safe method for breast cancer treatment, and expands the application of immunotherapy.

Arginine-Loaded Nano-Calcium-Phosphate-Stabilized Lipiodol Pickering Emulsions Potentiates Transarterial Embolization-Immunotherapy

Transarterial chemoembolization (TACE) continues to stand as a primary option for treating unresectable hepatocellular carcinoma (HCC). However, the increased tumor hypoxia and acidification will lead to the immunosuppressive tumor microenvironment (TME) featuring exhausted T cells, limiting the effectiveness of subsequent therapies following TACE. Herein, a stable water-in-oil lipiodol Pickering emulsion by employing calcium phosphate nanoparticles (CaP NPs) as stabilizers is developed and used to encapsulate L-arginine (L-Arg), which is known for its ability to modulate T-cell metabolism. The obtained L-Arg-loaded CaP-stabilized lipiodol Pickering emulsion (L-Arg@CaPL) with great emulsion stability can not only neutralize the tumor acidity via reaction of CaP NPs with protons but also enable the release of L-Arg, thereby synergistically promoting the reinvigoration of exhausted CD8+ T cells and effectively reversing tumor immunosuppression. As a result, TACE therapy with L-Arg@CaPL shows greatly improved therapeutic responses as demonstrated in an orthotopic liver tumor model in rats. This study highlights an effective yet simple nanoparticle-stabilized Pickering emulsion strategy to promote TACE therapy via modulation of the immunosuppressive TME, presenting great potential for clinical translation.

Manganese Galvanic Cells Intervene in Tumor Metabolism to Reinforce cGAS-STING Activation for Bidirectional Synergistic Hydrogen-Immunotherapy

The cGAS-STING pathway is pivotal in initiating antitumor immunity. However, tumor metabolism, particularly glycolysis, negatively regulates the activation of the cGAS-STING pathway. Herein, Mn galvanic cells (MnG) are prepared via liquid-phase exfoliation and in situ galvanic replacement to modulate tumor metabolism, thereby enhancing cGAS-STING activation for bidirectional synergistic H2-immunotherapy. The obtained MnG can be etched by water, enabling efficient and sustained generation of H2 gas and Mn2+. MnG not only activated and amplified the cGAS-STING pathway through the sustained release of Mn2+ but also regulated tumor glucose metabolism to inhibit the expression of three prime repair exonuclease 2 (TREX2), thereby synergistically enhancing the activation of the cGAS-STING pathway. The injection of MnG into tumors resulted in a robust immune response, thereby providing favorable support for antitumor therapy. Consequently, the combination of MnG with immune checkpoint blockade therapy resulted in significant suppression of both primary tumors and distant tumors. Furthermore, the MnG-lipiodol dispersion exhibited remarkable efficacy in combination with transarterial embolization (TAE)-gas-immunotherapy in a rabbit orthotopic liver tumor model. The present study underscores the significance of employing a metal galvanic cell strategy for enhanced immunotherapy, thereby offering a novel approach for rational design of bioactive materials to augment immunotherapeutic effectiveness.

Self-Cascaded Pyroptosis-STING Initiators for Catalytic Metalloimmunotherapy

Gasdermin (GSDM)-mediated pyroptosis involves the induction of mitochondrial damage and the subsequent release of mitochondrial DNA (mtDNA), which is anticipated to activate the cGAS-STING pathway, thereby augmenting the antitumor immune response. However, challenges lie in effectively triggering pyroptosis in cancer cells and subsequently enhancing the cGAS-STING activation with specificity. Herein, we developed intelligent self-cascaded pyroptosis-STING initiators of cobalt fluoride (CoF2) nanocatalysts for catalytic metalloimmunotherapy. CoF2 nanocatalysts with a semiconductor structure and enzyme-like activity generated a substantial amount of reactive oxygen species (ROS) under stimulation by endogenous H2O2 and exogenous ultrasound. Importantly, we discovered that Co-based nanomaterials themselves induce pyroptosis in cancer cells. Therefore, CoF2 nanocatalysts initially acted as pyroptosis inducers, triggering caspase-1/GSDMD-dependent pyroptosis in cancer cells via Co2+ and ROS, leading to mtDNA release. Subsequently, CoF2 nanocatalysts were further utilized as intelligent STING agonists that were specifically capable of detecting mtDNA and augmenting the activation of the cGAS-STING pathway. These cascade events triggered a robust immune response, effectively modulating the immunosuppressive tumor microenvironment into an immune-supportive state, thereby providing favorable support for antitumor therapy. This innovative strategy not only significantly impeded the growth of the primary tumor but also elicited an immune response to further augment the efficacy of immune checkpoint inhibitors in preventing distant tumor progression. Overall, this study proposed a self-cascade strategy for activating and amplifying the cGAS-STING pathway with specificity mediated by pyroptosis, representing a valuable avenue for future cancer catalytic metalloimmunotherapy.

Biomaterials enhancing localized cancer therapy activated anti-tumor immunity: a review

Localized cancer therapies such as radiotherapy, phototherapy, and chemotherapy are precise cancer treatment strategies aimed at minimizing systemic side effects. However, cancer metastasis remains the primary cause of mortality among cancer patients in clinical settings, and localized cancer treatments have limited efficacy against metastatic cancer. Therefore, researchers are exploring strategies that combine localized therapy with immunotherapy to activate robust anti-tumor immune responses, thereby eradicating metastatic cancer. Biomaterials, as novel materials, exhibit great potential in biomedical applications and have achieved great progress in clinic translation. This review introduces biomaterials and their applications in research focused on enhancing localized cancer treatment activated anti-tumor immunity. Additionally, the current challenges and future directions of biomaterials are also discussed, providing insights and references for related research.

Autophagy inhibition mediated via an injectable and NO-releasing hydrogel for amplifying the antitumor efficacy of mild magnetic hyperthermia

While mild hyperthermia holds great potential in the treatment of solid tumors, the thermal stress-triggered self-repairing autophagy significantly compromises its efficacy. To circumvent this obstacle, an injectable hydrogel (NO-Gel) composed of thermosensitive poly(ethylene glycol)-polypeptide copolymers modified with abundant NO donors on their side chains is developed. Meanwhile, ferrimagnetic Zn0.5Fe2.5O4 magnetic nanoparticles (MNPs) with high magnetic-heat conversion efficiency are synthesized and loaded into NO-Gel to obtain MNPs@NO-Gel. The MNPs@NO-Gel system exhibits a sol-gel transition upon heating, and has the ability to perform multiple magnetic hyperthermia therapy (MHT) after only one administration due to the even distribution and strong immobilization of MNPs in NO-Gel. NO can be continuously liberated from NO-Gel and this process is markedly accelerated by MHT. Additionally, MNPs@NO-Gel maintains its integrity in vivo for over one month and the released MNPs are metabolized by the spleen. After a single administration of MNPs@NO-Gel at the tumor site, three mild MHT treatments with similar effects are fulfilled, and the sufficient supply of NO effectively inhibits MHT-induced autophagic flux via blocking the formation of autophagosomes and synchronously destroying lysosomes, thereby substantially boosting the efficacy of mild MHT. As a consequence, CT-26 colon tumors are completely eliminated without causing severe side-effects.

An emerging antibacterial nanovaccine for enhanced chemotherapy by selectively eliminating tumor-colonizing bacteria

Fusobacterium nucleatum (F. nucleatum), an oral anaerobe, is prevalent in colorectal cancer and is closely related to increased cancer cell growth, metastasis, and poor treatment outcomes. Bacterial vaccines capable of selectively eliminating bacteria present a promising approach to targeting intratumor F. nucleatum, thereby enhancing cancer treatment. Although adjuvants have been employed to enhance the immune response, the vaccine's effectiveness is constrained by inadequate T-cell activation necessary for eradicating intracellular pathogens. In this study, we developed a minimalistic, biomimetic nanovaccine by integrating highly immunostimulatory adjuvant cholesterol-modified CpG oligonucleotides into the autologously derived F. nucleatum membranes. Compared to the traditional vaccines consisting of inactivated bacteria and Alum adjuvant, the nanovaccine coupled with bacterial membranes and adjuvants could remarkably improve multiple antigens and adjuvant co-delivery to dendritic cells, maximizing their ability to achieve effective antigen presentation and strong downstream immune progress. Notably, the nanovaccine exhibits outstanding selective prophylactic and therapeutic effects, eliminating F. nucleatum without affecting intratumoral and gut microbiota. It significantly enhances chemotherapy efficacy and reduces cancer metastasis in F. nucleatum-infected colorectal cancer. Overall, this work represents the rational application of bacterial nanovaccine and provides a blueprint for future development in enhancing the antitumor effect against bacterial-infected cancer.

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.

Fluorinated Titanium Oxide (TiO2-xFx) Nanospindles as Ultrasound-Triggered Pyroptosis Inducers to Boost Sonodynamic Immunotherapy

Pyroptosis is an inflammatory form of programmed cell death associated with the immune system that can be induced by reactive oxygen species (ROS). As a therapeutic strategy with better penetration depth, sonodynamic therapy (SDT) is expected to induce pyroptosis of cancer cells and boost the immune response. However, it is still a limited problem to precisely adjust the structure of sonosensitizers to exhibit satisfactory sono-catalytic properties. Herein, fluorinated titanium oxide (TiO2-xFx) sonosensitizers were developed to induce pyroptosis under ultrasound (US) to boost antitumor immune responses, enabling highly effective SDT. On the one hand, the introduction of F atoms significantly reduced the adsorption energy of TiO2-xFx for oxygen and water, which is conducive to the occurrence of sono-catalytic reactions. On the other hand, the process of F replacing O increased the oxygen vacancies of the sonosensitizer and shortened the band gap, which enabled powerful ROS generation ability under US stimulation. In this case, large amounts of ROS could effectively kill cancer cells by inducing mitochondrial damage and disrupting oxidative homeostasis, leading to significant cell pyroptosis. Moreover, SDT treatment with TiO2-xFx not only suppressed tumor proliferation but also elicited robust immune memory effects and hindered tumor recurrence. This work highlighted the importance of precisely regulating the structure of sonosensitizers to achieve efficient ROS generation for inducing pyroptosis, which sets the stage for the further development of SDT-immunotherapy.

Shape Self-Adaptive Liquid Embolic Agent for Ultrafast and Durable Vascular Embolization

Minimally invasive embolization greatly decreases the mortality resulting from vascular injuries while still suffering from a high risk of recanalization and systematic thrombosis due to the intrinsic hydrophobicity and poor adhesion of the clinically used liquid embolic agent of Lipiodol. In this study, a shape self-adaptive liquid embolic agent was developed by mixing biocompatible poly(acrylic acid) (PAA), two-dimensional magnesium-aluminum layered double hydroxide (LDH), and poly(ethylene glycol)200 (PEG200). Upon contact with blood, the injectable PAA-LDH@PEG200 would quickly absorb water to form an adhesive and mechanically strong PAA-LDH thin hydrogel within 5 s, which could firmly adhere to the blood vessel wall for ultrafast and durable embolization. In addition, benefiting from the "positively charged nucleic center effect" of LDH nanosheets, the liquid PAA-LDH@PEG200 could avoid vascular distension by PAA overexpansion and possess high shock-resistant mechanical strength from the blood flow. Furthermore, both in vitro and in vivo embolization experiments demonstrated the complete embolic capacity of liquid PAA-LDH@PEG200 without the occurrence of recanalization for 28 days and also the great potential to act as a platform to couple with chemotherapeutic drugs for the minimized transcatheter arterial chemoembolization (TACE) treatment of VX2 tumors without recurrence for 18 days. Thus, liquid PAA-LDH@PEG200 developed here possesses great potential to act as a shape self-adaptive liquid embolic agent for ultrafast and durable vascular embolization.

Polymer Microspheres and Their Application in Cancer Diagnosis and Treatment

Cancer is a significant global public health issue with increasing morbidity and mortality rates. To address this challenge, novel drug carriers such as nano-materials, liposomes, hydrogels, fibers, and microspheres have been extensively researched and utilized in oncology. Among them, polymer microspheres are gaining popularity due to their ease of preparation, excellent performance, biocompatibility, and drug-release capabilities. This paper categorizes commonly used materials for polymer microsphere preparation, summarizes various preparation methods (emulsification, phase separation, spray drying, electrospray, microfluidics, and membrane emulsification), and reviews the applications of polymer microspheres in cancer diagnosis, therapy, and postoperative care. The current status and future development directions of polymer microspheres in cancer treatment are analyzed, highlighting their importance and potential for improving patient outcomes.

A multifunctional CaCO3 bioreactor coated with coordination polymers enhances cancer immunotherapy

Designing effective nanomedicines to induce durable anti-tumor immunity represents a promising strategy for improving moderate immune stimulation. In this study, we engineered a multifunctional nanoreactor (named SCGFP NPs) for remodeling the tumor microenvironment (TME) to improve the therapeutic efficacy of immunotherapy. The core of SCGFP NPs consists of CaCO3 loaded with SN38, prepared by the gas diffusion method, and coated with a significant amount of gallic acid-Fe3+-PEG coordination polymer on the surface. In the acidic TME, SCGFP NPs explosively release exogenous Ca2+ and SN38. The SN38-induced intracellular Ca2+ accumulation and exogenous Ca2+ synergistically trigger immunogenic cell death (ICD) through sustained Ca2+ overload. The ablation of tumors with high-intensity photothermal therapy (PTT) by near-infrared (NIR) irradiation of GA-Fe3+ induces tumor cell necrosis, further enhancing ICD activation. Additionally, SN38 upregulates PD-L1, amplifying tumor responsiveness to immune checkpoint inhibitors (ICIs). This study indicates that SCGFP NPs, through the integration of a trimodal therapeutic strategy, hold enormous potential for various types of tumor immunotherapy through distinct mechanisms or synergistic effects.

Effect of surface modification on the distribution of magnetic nanorings in hepatocellular carcinoma and immune cells

Magnetic nanomaterial-mediated magnetic hyperthermia is a localized heating treatment modality that has been applied to treat aggressive cancer in clinics. In addition to being taken up by tumor cells to function in cancer therapy, magnetic nanomaterials can also be internalized by immune cells in the tumor microenvironment, which may contribute to regulating the anti-tumor immune effects. However, there exists little studies on the distribution of magnetic nanomaterials in different types of cells within tumor tissue. Herein, ferrimagnetic vortex-domain iron oxide nanorings (FVIOs) with or without the liver-cancer-targeting peptide SP94 have been successfully synthesized as a model system to investigate the effect of surface modification of FVIOs (with or without SP94) on the distribution of tumor cells and different immune cells in hepatocellular carcinoma (HCC) microenvironment of a mouse. The distribution ratio of FVIO-SP94s in tumor cells was 1.3 times more than that of FVIOs. Immune cells in the liver tumor microenvironment took up fewer FVIO-SP94s than FVIOs. In addition, myeloid cells were found to be much more amenable than lymphoid cells in terms of their ability to phagocytose nanoparticles. Specifically, the distributions of FVIOs/FVIO-SP94s in tumor-associated macrophages, dendritic cells, and myeloid-derived suppressor cells were 13.8%/12%, 3.7%/0.9%, and 6.3%/1.2%, respectively. While the distributions of FVIOs/FVIO-SP94s in T cells, B cells, and natural killer cells were 5.5%/0.7%, 3.0%/0.7%, and 0.4%/0.3%, respectively. The results described in this article enhance our understanding of the distribution of nanomaterials in the tumor microenvironment and provide a strategy for rational design of magnetic hyperthermia agents that can effectively regulate anti-tumor immune effects.

Theranostics: a multifaceted approach utilizing nano-biomaterials

Biomaterials play a vital role in targeting therapeutics. Over the years, several biomaterials have gained wide attention in the treatment and diagnosis of diseases. Scientists are trying to make more personalized treatments for different diseases, as well as discovering novel single agents that can be used for prognosis, medication administration, and keeping track of how a treatment works. Theranostics based on nano-biomaterials have higher sensitivity and specificity for disease management than conventional techniques. This review provides a concise overview of various biomaterials, including carbon-based materials like fullerenes, graphene, carbon nanotubes (CNTs), and carbon nanofibers, and their involvement in theranostics of different diseases. In addition, the involvement of imaging techniques for theranostics applications was overviewed. Theranostics is an emerging strategy that has great potential for enhancing the accuracy and efficacy of medicinal interventions. Despite the presence of obstacles such as disease heterogeneity, toxicity, reproducibility, uniformity, upscaling production, and regulatory hurdles, the field of medical research and development has great promise due to its ability to provide patients with personalised care, facilitate early identification, and enable focused treatment.

Self-fueling ferroptosis-inducing microreactors based on pH-responsive Lipiodol Pickering emulsions enable transarterial ferro-embolization therapy

Lipiodol chemotherapeutic emulsions remain one of the main choices for the treatment of unresectable hepatocellular carcinoma (HCC) via transarterial chemoembolization (TACE). However, the limited stability of Lipiodol chemotherapeutic emulsions would lead to rapid drug diffusion, which would reduce the therapeutic benefit and cause systemic toxicity of administrated chemotherapeutics. Therefore, the development of enhanced Lipiodol-based formulations is of great significance to enable effective and safe TACE treatment. Herein, a stable water-in-oil Lipiodol Pickering emulsion (LPE) stabilized by pH-dissociable calcium carbonate nanoparticles and hemin is prepared and utilized for efficient encapsulation of lipoxygenase (LOX). The obtained LOX-loaded CaCO3&hemin-stabilized LPE (LHCa-LPE) showing greatly improved emulsion stability could work as a pH-responsive and self-fueling microreactor to convert polyunsaturated fatty acids (PUFAs), a main component of Lipiodol, to cytotoxic lipid radicals through the cascading catalytic reaction driven by LOX and hemin, thus inducing ferroptosis of cancer cells. As a result, such LHCa-LPE upon transcatheter embolization can effectively suppress the progression of orthotopic N1S1 HCC in rats. This study highlights a concise strategy to prepare pH-responsive and stable LPE-based self-fueling microreactors, which could serve as bifunctional embolic and ferroptosis-inducing agents to enable proof-of-concept transarterial ferro-embolization therapy of HCC.

Hyperthermia-embolization-immunotherapy: a potent trio in advancing cancer treatment

Yang et al. recently demonstrated the high potential of liquid metal microspheres (LM MSs) in cancer therapy. By amplifying the effects of magnetic hyperthermia and embolization, LM MSs not only target primary tumors, but also potentiate immune defenses. This dual-action approach effectively curtails distant tumor growth, marking a pivotal advancement in cancer immunotherapy.