Mild Magnetic Hyperthermia-Activated Innate Immunity for Liver Cancer Therapy

Magnetotactic bacteria-mediated integrated magnetic targeted hyperthermia for in-situ deep-seated tumor

Unlike hyperthermia after intratumoral injection, the method of integrated magnetic targeted hyperthermia (iMTH) guides magnetic medium to the target site and then directly performs in-situ heating, showing great potential for effective treatment of deep-seated tumors in the body. Magnetotactic bacteria (MTB), having chain-like arranged magnetic nanoparticles within its body and active movement along an external magnetic field, are considered as a very fitted material for iMTH. However, the amount of MTB concentrated on the deep-seated tumor posed a significant challenge for the successful implementation of iMTH. Herein, we aim to validate the strategy of integrating magnetic targeting and hyperthermia. An in-situ liver tumor model in mouse was developed as deep-seated tumors. After administering the polar MTB MO-1 intravenously via the tail vein, a focusing magnetic field navigated these bacteria to effectively accumulate at the deep-seated tumor site. Immediately afterwards, this targeted aggregation of MO-1 cells triggered a localized magnetic hyperthermia directly at the cancer site under an applied alternating magnetic field. Our findings demonstrated that this hyperthermia induced by the bacteria led to the death of liver cancer cells, thereby effectively curbing the progression and growth of the cancer. These promising results suggested that an iMTH approach was developed, harnessing the power of MTB. This method stands as an exciting and potential therapeutic strategy for the treatment of deep-seated tumors, offering new hope in the fight against cancer.

Bioactive microspheres to enhance sonodynamic-embolization-metalloimmune therapy for orthotopic liver cancer

The development of novel microspheres for the combination of sonodynamic therapy (SDT) with transarterial embolization (TAE) therapy to amplify their efficacy has received increasing attention. Herein, a novel strategy for encapsulating sonosensitizers (e.g., oxygen-deficient manganese tungstate (MnWOX) nanodots) with gelatin microspheres was proposed. The obtained MnWOX-encapsulated microspheres (abbr. Mn-GMSs) facilitated efficient sonodynamic-embolization-metalloimmune therapy via the immune effects of metal ions on orthotopic liver cancer tumor after transarterial embolization (TAE). Due to the strong cavitation effect caused by the porous structure, Mn-GMSs exhibited a greater reactive oxygen species (ROS) generation rate than the free MnWOX nanodots under US irradiation. Efficient SDT revealed robust cell-killing effects and triggered strong immunogenic cell death (ICD). Moreover, the Mn ions released from the bioactive Mn-GMSs further stimulated the dendritic cells (DCs) maturation and triggered the activation of the cGAS/STING pathway to enhance the immunological effect. Thus, Mn-GMSs achieved significant SDT therapeutic outcomes in H22 tumors in mice, and the combination of the Mn-GMSs triggered SDT with programmed cell death ligand 1 (PD-L1) antibodies could further enhance therapeutic outcomes. The Mn-GMSs exhibited high ROS generation efficacy under US irradiation, significant immune activation, good efficacy in combination with immune checkpoint inhibitor, and great potential for artery embolization-assisted drug delivery, thus enabling effective destruction of liver tumors in rats and rabbits. Therefore, this work provides a strategy for applying SDT in deep tumors and highlights a promising sonodynamic-embolization therapy for combating liver cancers.

Precise size control of superparamagnetic Fe3O4 nanoparticles for liver cancer diagnosis and magnetic hyperthermia therapy

Multifunctional superparamagnetic iron oxide nanoparticles are pivotal in bioapplications, with optimal size ranges varying by application. Exploring each size is essential to maximize functionality, as even 1-2 nm variations can significantly affect their properties. Therefore, discussing the effects of different sizes within the single-domain range of superparamagnetic ferrites is essential for understanding their performance in bioapplications. In this study, we synthesize monodisperse Fe3O4 nanoparticles with diameter ranging from 4.0 to 13.5 nm, the surface modified with PEGylated (Fe3O4-mPEG2000; FP), and systematically evaluate size-dependent biobehavior and potential application of FP nanoparticles in SNU423 cells. The results reveal that specific loss power (SLP) is directly proportional to particle size, and the larger FP nanoparticles enable higher hyperthermal ablation efficacy in vitro, leading to more effective tumor growth inhibition in vivo. Meanwhile, particles with smaller sizes (< 8.5 nm) generate negligible heat, rendering them unsuitable for hyperthermal therapy, but optimal for magnetic resonance imaging (MRI). This work demonstrates that FPs nanoparticles with diameter of 13.5 nm exhibit a significant synergistic anticancer effect of magnetic hyperthermal therapy and effective T2-weighted MRI with minimal side effects. This research presents important insights for nanoparticle design by precisely identifying the suitable size ranges for the biofunctions of Fe3O4 nanoparticles.

Electromagnetic fields regulate iron metabolism: From mechanisms to applications

BACKGROUND

Electromagnetic fields (EMFs), as a form of physical therapy, have been widely applied in biomedicine. Iron, the most abundant trace metal in living organisms, plays a critical role in various physiological processes, and imbalances in its metabolism are closely associated with the development and progression of numerous diseases. Numerous studies have demonstrated that EMF exposureinduces significant changes in both systemic and cellular iron metabolism.

AIM OF REVIEW

This review aims to summarize the evidence and potential biophysical mechanisms underlying the role of EMFs in regulating iron metabolism, thereby enhancing the understanding of their biological mechanisms and expanding their potential applications in biomedical fields.

KEY SCIENTIFIC CONCEPTS OF REVIEW

In this review, we have synthesized research findings and proposed the hypothesis that the biophysical mechanisms of EMFs regulate iron metabolism involve the special electromagnetic properties of iron-containing proteins and iron-enriched tissues, as well as the modulation of membrane structure and function, ion channels, and the generation and activity of Reactive Oxygen Species (ROS). Then, the review summarizes the latest advances in the effects of EMFs on iron metabolism and their safety, as well as their impact on immunoregulation, cardiovascular diseases, neurological diseases, orthopedic diseases, diabetes, liver injury, and cancer.

Magnetothermal and ultrasound-activated nanoplatform for the inhalable therapy of bacterial lung infections

Antibiotic resistance in Klebsiella pneumoniae infections presents significant challenges in treating lung inflammation. To overcome tissue penetration barriers and modulate inflammatory responses, innovative therapeutic approaches are essential. This study introduces an inhalable nanoplatform, FexSy:Gd@PVP (FGP), based on polyvinylpyrrolidone-modified gadolinium-doped nonstoichiometric iron sulfide nanostructures. The platform integrates synergistic magnetic-ultrasound activation with magnetothermal therapy (mMHT), sonodynamic therapy (SDT), and gas therapy (GT) for targeted bacterial lung infection treatment. Gadolinium incorporation enhances the magnetothermal activation, improving magnetothermal conversion efficiency and sonodynamic performance by increasing magnetic anisotropy, narrowing the semiconductor bandgap, and enriching sulfur vacancies. Delivered via nebulized inhalation, FGP reaches infected lung tissues noninvasively. Exposure to alternating magnetic fields (AMF) and ultrasound (US) generates localized heat and reactive oxygen species (ROS), effectively eliminating bacteria. Simultaneously, AMF and US trigger hydrogen sulfide (H2S) release in the acidic microenvironment, reducing inflammation by inhibiting inflammatory factors such as TNF-α and IL-1β through suppression of STAT3 and ERK phosphorylation. This magnetic-ultrasound co-activated inhalable nanoplatform offers a powerful multimodal therapeutic strategy for overcoming clinical challenges associated with bacterial lung infections. STATEMENT OF SIGNIFICANCE: This study introduces an inhalable nanoplatform that effectively treats multidrug-resistant Klebsiella pneumoniae lung infections. By integrating magnetothermal, sonodynamic, and gas therapies, this system eradicates bacteria and reduces inflammation. It uses gadolinium-doped iron sulfide nanostructures to enhance heat, reactive oxygen species, and hydrogen sulfide production, targeting deep lung infections precisely. Unlike traditional antibiotics, this noninvasive approach has minimal side effects and addresses both bacterial clearance and inflammation. This innovative strategy offers a promising solution for antibiotic-resistant infections and could revolutionize respiratory disease management.

A CLDN18.2-Targeted Nanoplatform Manipulates Magnetic Hyperthermia Spatiotemporally for Synergistic Immunotherapy in Gastric Cancer

Precision treatment of gastric cancer requires specific biomarkers, and CLDN18.2 emerges as a promising target for patients' stratification and therapeutic guidance. In 563 cases, 54.4% of patients are identified as CLDN18.2-positive, with CLDN18.2 expression negatively correlated with immune-related factors like PD-L1, indicating a "cold" tumor microenvironment. Here, a novel CLDN18.2 monoclonal antibody 1D5 is created with superior high specificity and affinity, and the antibody-dependent fluorescence-magnetic nanoparticle is developed for specific detection and magnetic hyperthermia (MHT). Under the assistance of sensitive fluorescence and deep-penetrating magnetic particle imaging for tracing and timing the optimal nanoparticle dosage, MHT induces robust immunogenic response via DNA mismatch repair and tumor-associated antigen release. It recruits CD11c+ dendritic cells, compensates PD-1 in CD8+ T cells, and enhances CD86+ macrophage polarization. The combination of anti-PD-1 therapy increased TNF-α and IFN-γ secretion and further boosted the cytotoxic efficacy of CD8+ T cells. Excellent therapeutic efficacy is found simultaneously on cell-derived allografts and patient-derived xenografts based on this spatiotemporally manipulated strategy, presenting a therapeutic option for enhancing responsiveness to immunotherapy for CLDN18.2-positive individuals.

Magnetically triggered thermoelectric heterojunctions with an efficient magnetic-thermo-electric energy cascade conversion for synergistic cancer therapy

Thermoelectric therapy has been emerging as a promising and versatile strategy for targeting malignant tumors treatment. However, the lack of effective time-space controlled triggering of thermoelectric effect in vivo limits the application of thermoelectric therapy. Here a magnetically triggered thermoelectric heterojunction (CuFe2O4/SrTiO3, CFO/STO) for synergistic thermoelectric/chemodynamic/immuno-therapy is developed. The efficient magnetothermal nanoagent (CFO) is synthesized using the hydrothermal method, and thermoelectric nanomaterials (STO) are grown on its surface to create the heterojunction. To enhance oral delivery efficiency, a fusion membrane (M) of Staphylococcus aureus and macrophage cell membranes are coated the CFO/STO heterojunction, enabling effective targeting of orthotopic colorectal cancer. Once the CFO/STO@M reaches the tumor region, in vitro alternating magnetic field (AMF) stimulation activates the catalytic treatment through a magnetic-thermo-electric energy cascade conversion effect. Additionally, the immunogenic death of tumor cells, down-regulating vascular endothelial growth factor and heat shock protein HSP70, increasing expression of endothelial cell adhesion molecule (ICAM-1/VCAM-1), and M1 polarization of macrophages contribute to tumor immunotherapy. Overall, the magnetically triggered thermoelectric heterojunction based on CFO/STO@M shows remarkable antitumor capability in female mice, offering a promising approach to broaden both the scope of application and the effectiveness of catalytic therapy.

A nitric oxide-boosting molecular agent to enhance mild-temperature photothermal therapy

A nitric oxide (NO)-boosting molecular agent (CyHU) was developed for enhanced mild-temperature photothermal therapy (MPTT). This photothermal agent can specifically target mitochondria and efficiently produce NO, inhibiting adenosine triphosphate-dependent heat shock proteins, reversing tumor heat tolerance and ultimately achieving MPTT of cancer cells.

Recent progress in cancer vaccines and nanovaccines

Vaccine science, nanotechnology, and immunotherapy are at the forefront of cancer treatment strategies, each offering significant potential for enhancing tumor-specific immunity and establishing long-lasting immune memory to prevent tumor recurrence. Despite the promise of these personalized and precision-based anti-cancer approaches, challenges such as immunosuppression, suboptimal immune activation, and T-cell exhaustion continue to hinder their effectiveness. The limited clinical success of cancer vaccines often stems from difficulties in identifying effective antigens, efficiently targeting immune cells, lymphoid organs, and the tumor microenvironment, overcoming immune evasion, enhancing immunogenicity, and avoiding lysosomal degradation. However, numerous studies have demonstrated that integrating nanotechnology with immunotherapeutic strategies in vaccine development can overcome these challenges, leading to potent antitumor immune responses and significant progress in the field. This review highlights the critical components of cancer vaccine and nanovaccine strategies for immunomodulatory antitumor therapy. It covers general vaccine strategies, types of vaccines, antigen forms, nanovaccine platforms, challenges faced, potential solutions, and key findings from preclinical and clinical studies, along with future perspectives. To fully unlock the potential of cancer vaccines and nanovaccines, precise immunological monitoring during early-phase trials is essential. This approach will help identify and address obstacles, ultimately expanding the available options for patients who are resistant to conventional cancer immunotherapies.

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.

From detection to elimination: iron-based nanomaterials driving tumor imaging and advanced therapies

Iron-based nanomaterials (INMs), due to their particular magnetic property, excellent biocompatibility, and functionality, have been developed into powerful tools in both tumor diagnosis and therapy. We give an overview here on how INMs such as iron oxide nanoparticles, element-doped nanocomposites, and iron-based organic frameworks (MOFs) display versatility for tumor imaging and therapy improvement. In terms of imaging, INMs improve the sensitivity and accuracy of techniques such as magnetic resonance imaging (MRI) and photoacoustic imaging (PAI) and support the development of multimodal imaging platforms. Regarding treatment, INMs play a key role in advanced strategies such as immunotherapy, magnetic hyperthermia, and synergistic combination therapy, which effectively overcome tumor-induced drug resistance and reduce systemic toxicity. The integration of INMs with artificial intelligence (AI) and radiomics further expands its capabilities for precise tumor identification, and treatment optimization, and amplifies treatment monitoring. INMs now link materials science with advanced computing and clinical innovations to enable next-generation cancer diagnostics and therapeutics.

Harnessing stimuli-responsive biomaterials for advanced biomedical applications

Cell behavior is intricately intertwined with the in vivo microenvironment and endogenous pathways. The ability to guide cellular behavior toward specific goals can be achieved by external stimuli, notably electricity, light, ultrasound, and magnetism, simultaneously harnessed through biomaterial-mediated responses. These external triggers become focal points within the body due to interactions with biomaterials, facilitating a range of cellular pathways: electrical signal transmission, biochemical cues, drug release, cell loading, and modulation of mechanical stress. Stimulus-responsive biomaterials hold immense potential in biomedical research, establishing themselves as a pivotal focal point in interdisciplinary pursuits. This comprehensive review systematically elucidates prevalent physical stimuli and their corresponding biomaterial response mechanisms. Moreover, it delves deeply into the application of biomaterials within the domain of biomedicine. A balanced assessment of distinct physical stimulation techniques is provided, along with a discussion of their merits and limitations. The review aims to shed light on the future trajectory of physical stimulus-responsive biomaterials in disease treatment and outline their application prospects and potential for future development. This review is poised to spark novel concepts for advancing intelligent, stimulus-responsive biomaterials.

In Situ Fabrication of Electrospun Magnetic Film under Laparoscopic Guidance for Preventing Postoperative Recurrence of Hepatocellular Carcinoma

Despite laparoscopic-guided minimally invasive hepatectomy emerging as the primary approach for resecting hepatocellular carcinoma (HCC), there is still a significant gap in suitable biomaterials that seamlessly integrate with these techniques to achieve effective hemostasis and suppress residual tumors at the surgical margin. Electrospun films are increasingly used for wound closure, yet the employment of prefabricated electrospun films for hemostasis during minimally invasive HCC resection is hindered by prolonged operation times, complexity in implementation, limited visibility during surgery, and inadequate postoperative prevention of HCC recurrence. In this study, montmorillonite-iron oxide sheets are integrated into the polyvinylpyrrolidone (PVP) polymer framework, enhancing the resulting electrospun PVP/montmorillonite-iron oxide (MI) film (abbreviated as PMI) with robustness, hemostatic capability, and magnetocaloric properties. In contrast to the in vitro prefabricated electrospun films, the electrospun PMI film is designed to be formed in situ on liver wounds under laparoscopic guidance during hepatectomy. This design affords superior wound adaptability, facilitating meticulous wound closure and expeditious hemostasis, thereby simplifying the operative process and ultimately alleviating the workload of healthcare professionals. Moreover, when exposed to an alternating magnetic field, the film can efficiently ablate residual tumors, significantly augmenting the treatment efficacy of HCC.

Nebulized Immunotherapy of Orthotopic Lung Cancer by Mild Magnetothermal-Based Innate Immunity Activations

Advances in adaptive immunity have greatly contributed to the development of cancer immunotherapy. However, its over-low efficacy and insufficient invasion of immune cells in the tumor tissue, and safety problems caused by cytokine storm, have seriously impeded further clinical application for solid tumor immunotherapy. Notably, the immune microenvironment of the lungs is naturally enriched with alveolar macrophages (AMs). Herein, we introduce a novel nebulized magnetothermal immunotherapy strategy to treat orthotopic lung cancer by using magnetothermal nanomaterial (Zn-CoFe2O4@Zn-MnFe2O4-PEG, named ZCMP), which can release iron ions via an acid/thermal-catalytic reaction to maximize the use of lung's immune environment through the cascade activations of AMs and natural killer (NK) cells. Nebulized administration greatly enhance drug bioavailability by localized drug accumulation at the lesion site. Upon mild magnetic hyperthermia, the released iron ions catalyze endogenous H2O2 decomposition to produce reactive oxygen species (ROS), which triggers the M1 polarization of AMs, and the resultant inflammatory cytokine IFN-β, IL-1β and IL-15 releases to activate c-Jun, STAT5 and GZMB related signaling pathways, promoting NK cells proliferation and activation. This innovative strategy optimally utilizes the lung's immune environment and shows excellent immunotherapeutic outcomes against orthotopic lung cancer.

Advanced Thermoactive Nanomaterials for Thermomedical Tissue Regeneration: Opportunities and Challenges

Nanomaterials usually possess remarkable properties, including excellent biocompatibility, unique physical and chemical characteristics, and bionic attributes, which make them highly promising for applications in tissue regeneration. Thermal therapy has emerged as a versatile approach for wound healing, nerve repair, bone regeneration, tumor therapy, and antibacterial tissue regeneration. By combining nanomaterials with thermal therapy, multifunctional nanomaterials with thermogenic effects and tissue regeneration capabilities can be engineered to achieve enhanced therapeutic outcomes. This study provides a comprehensive review of the effects of thermal stimulation on cellular and tissue regeneration. Furthermore, it highlights the applications of photothermal, magnetothermal, and electrothermal nanomaterials, and thermally responsive drug delivery systems in tissue engineering. In Addition, the bioactivities and biocompatibilities of several representative thermal nanomaterials are discussed. Finally, the challenges facing thermal nanomaterials are outlined, and future prospects in the field are presented with the aim of offering new opportunities and avenues for the utilization of thermal nanomaterials in tissue regeneration.

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.

Combination Using Magnetic Iron Oxide Nanoparticles and Magnetic Field for Cancer Therapy

Iron oxide nanoparticles (MNPs) demonstrate notable benefits in magnetic induction, attributed to their distinctive physical and chemical attributes. Emerging cancer treatment utilizing magnetic fields have also gathered increasing attention in the biomedical field. However, the defects of difficult dispersion and poor biocompatibility of MNPs seriously hinder their application. In order to overcome its inherent defects and maximize the therapeutic potential of MNPs, various functionalized MNPs have been developed, and numerous combined treatment methods based on MNPs have been widely studied. In this review, we compare and analyze the common nanoparticles based on MNPs with different sizes, shapes, and functional modifications. Additionally, we introduced the therapeutic mechanisms of the strategies, such as magnetically controlled targeting, magnetic hyperthermia, and magneto-mechanical effect, which based on the unique magnetic induction capabilities of MNPs. Finally, main challenges of MNPs as smart nanomaterials were also discussed. This review seeks to offer a thorough overview of MNPs in biomedicine and a new sight for their application in tumor treatment.

The role of hyperthermia in the treatment of tumor

Despite recent advancements in the diagnosis and treatment options for cancer, it remains one of the most serious threats to health. Hyperthermia (HT) has emerged as a highly promising area of research due to its safety and cost-effectiveness. Currently, based on temperature, HT can be categorized into thermal ablation and mild hyperthermia. Thermal ablation involves raising the temperature within the tumor to over 60°C, resulting in direct necrosis in the central region of the tumor. In contrast, mild hyperthermia operates at relatively lower temperatures, typically in the range of 41-45°C, to induce damage to tumor cells. Furthermore, HT also serves as an immune adjuvant strategy in radiotherapy, chemotherapy, and immunotherapy, enhancing the effectiveness of radiotherapy, increasing the uptake of chemotherapy drugs, and reprogramming the tumor microenvironment through the induction of immunogenic cell death, thereby promoting the recruitment of endogenous immune cells. This article reviews the current status and development of hyperthermia, outlines potential mechanisms by which hyperthermia inhibits tumors, describes clinical trial attempts combining hyperthermia with radiotherapy, chemotherapy, and immunotherapy, and discusses the relationship between nanoparticles and hyperthermia.

Recent advances of injectable in situ-forming hydrogels for preventing postoperative tumor recurrence

The unavoidable residual tumor tissue from surgery and the strong aggressiveness of tumor cells pose challenges to the postoperative treatment of tumor patients, accompanied by in situ tumor recurrence and decreased quality of life. Therefore, there is an urgent need to explore appropriate postoperative therapeutic strategies to remove residual tumor cells after surgery to inhibit tumor recurrence and metastasis after surgery. In recent years, with the rapid development of biomedical materials, the study of local delivery systems as postoperative delivery of therapeutic agents has gradually attracted the attention of researchers. Injectable in situ-forming hydrogel is a locally administered agent injected in situ as a solution that can be loaded with various therapeutic agents and rapidly gels to form a semi-solid gel at the treatment site. This type of hydrogel tightly fills the surgical site and covers irregular excision surfaces. In this paper, we review the recent advances in the application of injectable in situ-forming hydrogels in postoperative therapy, focusing on the matrix materials of this type of hydrogel and its application in the postoperative treatment of different types of tumors, as well as discussing the challenges and prospects of its clinical application.

Immunomodulatory metal-based biomaterials for cancer immunotherapy

Cancer immunotherapy, as an emerging cancer treatment approach, harnesses the patient's own immune system to effectively prevent tumor recurrence or metastasis. However, its clinical application has been significantly hindered by relatively low immune response rates. In recent years, metal-based biomaterials have been extensively studied as effective immunomodulators and potential tools for enhancing anti-tumor immune responses, enabling the reversal of immune suppression without inducing toxic side effects. This review introduces the classification of bioactive metal elements and summarizes their immune regulatory mechanisms. In addition, we discuss the immunomodulatory roles of biomaterials constructed from various metals, including aluminum, manganese, gold, calcium, zinc, iron, magnesium, and copper. More importantly, a systematic overview of their applications in enhancing immunotherapy is provided. Finally, the prospects and challenges of metal-based biomaterials with immunomodulatory functions in cancer immunotherapy are outlined.

Hyaluronic acid-zein shell-core biopolymer nanoparticles enhance hepatocellular carcinoma therapy of celastrol via CD44-mediated cellular uptake

Low concentrations or limited residence times in tumor tissues, making celastrol (Cel) difficult to exert significant therapeutic effects. Thus, we developed Zein/hyaluronic acid core-shell nanoparticles (Cel/Zein@HA NPs) for active targeted delivery of Cel via CD44 receptor over-expression on cancer cells, which may strengthen the therapeutic efficacy of Cel and improve delivery targeting. Cel-loaded Zein nanoparticles (core), are elegantly enveloped by a hydrophilic HA coating that forms the shell, resulting in significantly improved encapsulation efficiency and ensured good stability. The cellular uptake of Cel/Zein@HA NPs in HepG2 cells was 1.57-fold higher than nontargeting Cel/Zein NPs. Near-infrared fluorescence imaging confirmed the accumulation of Cel/Zein@HA NPs in H22 liver cancer tumors in mice, resulting in effective antitumor effects and good biosafety. Besides, in vitro and in vivo experiments showed that compared with Cel/Zein NPs, Cel/Zein@HA NPs had more efficient inhibitory effect on tumor proliferation and lower systemic toxicity. Further studies revealed that Cel/Zein@HA NPs induced apoptosis in hepatocellular carcinoma cells by modulating Bax and Bcl-2 expression, while also inhibiting tumor angiogenesis by decreasing CD31 and VEGF levels. Overall, this study presents a promising strategy for enhancing targeted liver cancer therapy through the utilization of biopolymer nanoparticle-based nano-pharmaceuticals that facilitate CD44-mediated cellular uptake.

Magnetic Induction Heating in a Conducting Polymer for Biomedical Applications

In this study, we investigate the magnetic induction heating induced in a conducting polymer (CP) under alternative magnetic fields (AMFs). Experimental results and numerical simulations have proved that the magneto-thermal conversion of the CP is caused by the induced eddy current, which is related to the shape and intensity of the applied external AMF, and the intrinsic electrical conductivity, macrostructure and microstructure of the CP. By employing various fabrication methods, specific temperature distribution and control of thermal field within conducting polymer films and aerogels could be achieved. To exploit the potential of magnetic induction heating in CP for biomedical applications, we designed a conducting polymer aerogel-based self-adaptive heat patch and demonstrated its AMF-enabled localized heating of skin. In addition to the thermal ablation of tumor cells via magneto-thermal conversion of the CP, the promotion of neuronal differentiation at mild temperature by noninvasive magneto-electrical stimulation has also been demonstrated to be an effective strategy for tissue engineering.

Magnetic nanoparticles and possible synergies with cold atmospheric plasma for cancer treatment

The biomedical applications of magnetic nanoparticles (MNPs) have gained increasing attention due to their unique biological, chemical, and magnetic properties such as biocompatibility, chemical stability, and high magnetic susceptibility. However, several critical issues still remain that have significantly halted the clinical translation of these nanomaterials such as the relatively low therapeutic efficacy, hyperthermia resistance, and biosafety concerns. To identify innovative approaches possibly creating synergies with MNPs to resolve or mitigate these problems, we delineated the anti-cancer properties of MNPs and their existing onco-therapeutic portfolios, based on which we proposed cold atmospheric plasma (CAP) to be a possible synergizer of MNPs by enhancing free radical generation, reducing hyperthermia resistance, preventing MNP aggregation, and functioning as an innovative magnetic and light source for magnetothermal- and photo-therapies. Our insights on the possible facilitating role of CAP in translating MNPs for biomedical use may inspire fresh research directions that, once actualized, gain mutual benefits from both.

Ultrathin Gd-Oxide Nanosheet as Ultrasensitive Companion Diagnostic Tool for MR Imaging and Therapy of Submillimeter Microhepatocellular Carcinoma

Early stage hepatocellular carcinoma (HCC) presents a formidable challenge in clinical settings due to its asymptomatic progression and the limitations of current imaging techniques in detecting micro-HCC lesions. Addressing this critical issue, we introduce a novel ultrathin gadolinium-oxide (Gd-oxide) nanosheet-based platform with heightened sensitivity for high-field MRI and as a therapeutic agent for HCC. Synthesized via a digestive ripening process, these Gd-oxide nanosheets exhibit an exceptional acid-responsive profile. The integration of the ultrathin Gd-oxide with an acid-responsive polymer creates an ultrasensitive high-field MRI probe, enabling the visualization of submillimeter-sized tumors with superior sensitivity. Our research underscores the ultrasensitive probe's efficacy in the treatment of orthotopic HCC. Notably, the ultrasensitive probe functions dually as a companion diagnostic tool, facilitating simultaneous imaging and therapy with real-time treatment monitoring capabilities. In conclusion, this study showcases an innovative companion diagnostic tool that holds promise for the early detection and effective treatment of micro-HCC.

Design of the distribution of iron oxide (Fe3O4) nano-particle drug in realistic cholangiocarcinoma model and the simulation of temperature increase during magnetic induction hyperthermia

The prognosis for Cholangiocarcinoma (CCA) is unfavorable, necessitating the development of new therapeutic approach such as magnetic hyperthermia therapy (MHT) which is induced by magnetic nano-particle (MNPs) drug to bridge the treatment gap. Given the deep location of CCA within the abdominal cavity and proximity to vital organs, accurately predict the individualized treatment effects and safety brought by the distribution of MNPs in tumor will be crucial for the advancement of MHT in CCA. The Mimics software was used in this study to conduct three-dimensional reconstruction of abdominal computed tomography (CT) and magnetic reso-nance imaging images from clinical patients, resulting in the generation of a realistic digital geometric model representing the human biliary tract and its adjacent structures. Subsequently, The COMSOL Multiphysics software was utilized for modeling CCA and calculating the heat transfer law resulting from the multi-regional distribution of MNPs in CCA. The temperature within the central region of irregular CCA measured approximately 46°C, and most areas within the tumor displayed temperatures surpassing 41°C. The temperature of the inner edge of CCA is only 39 ∼ 41℃, however, it can be ameliorated by adjusting the local drug concentration through simulation system. For CCA with diverse morphologies and anatomical locations, the multi-regional distribution patterns of intratumoral MNPs and a slight overlap of drug distribution areas synergistically enhance intratumoral temperature while ensuring treatment safety. The present study highlights the practicality and imperative of incorporating personalized intratumoral MNPs distribution strategy into clinical practice for MHT, which can be achieved through the development of an integrated simulation system which incorporates medical image data and numerical calculations.

Magnetic iron oxide nanogels for combined hyperthermia and drug delivery for cancer treatment

Hyperthermia and chemotherapy represent potential modalities for cancer treatments. However, hyperthermia can be invasive, while chemotherapy drugs often have severe side effects. Recent clinical investigations have underscored the potential synergistic efficacy of combining hyperthermia with chemotherapy, leading to enhanced cancer cell killing. In this context, magnetic iron oxide nanogels have emerged as promising candidates as they can integrate superparamagnetic iron oxide nanoparticles (IONPs), providing the requisite magnetism for magnetic hyperthermia, with the nanogel scaffold facilitating smart drug delivery. This review provides an overview of the synthetic methodologies employed in fabricating magnetic nanogels. Key properties and designs of these nanogels are discussed and challenges for their translation to the clinic and the market are summarised.

Advances in magnetic induction hyperthermia

Magnetic induction hyperthermia (MIH), is a technique that has developed rapidly in recent years in the field of tumor thermotherapy. It implants a magnetic heating medium (millimeter-sized heat seeds, micron-sized magnetic particles and nanometer-sized magnetic fluids, etc.) inside the tumor. The material heats up under the induction of an external alternating magnetic field (100-500 kHz), which causes a high temperature zone to rapidly form in the local biological tissues and induces apoptosis in tumor cells. Magnetic induction hyperthermia has the advantages of high safety, strong targeting, repeatable treatment, and the size of the incision during treatment is negligible compared to surgical resection, and is currently used in clinical treatment. However, the millimeter-scale heat seed heating that is typically used in treatments can result in uneven temperatures within the tissue. Common MIH heating devices are bulky and complex in design, and are not easy for medical staff to get their hands on, which are issues that limit the diffusion of MIH. In this view, this paper will discuss the basic theoretical research on MIH and the progress of MIH-related technologies, with a focus on the latest research and development results and research hotspots of nanoscale ferromagnetic media and magnetic heat therapy devices, as well as the validation results and therapeutic efficacy of the new MIH technology on animal experiments and clinical trials. In this paper, it is found that induction heating using magnetic nanoparticles improves the uniformity of the temperature field, and the magneto-thermal properties of nanoscale ferromagnetic materials are significantly improved. The heating device was miniaturized to simplify the operation steps, while the focusing of the magnetic field was locally enhanced. However, there are fewer studies on the biotoxicity aspects of nanomedicines, and the localized alternating magnetic field uniformity used for heating and the safety of the alternating magnetic field after irradiation of the human body have not been sufficiently discussed. Ultimately, the purpose of this paper is to advance research related to magnetic induction thermotherapy that can be applied in clinical treatment.

Recent Progress in Photothermal, Photodynamic and Sonodynamic Cancer Therapy: Through the cGAS-STING Pathway to Efficacy-Enhancing Strategies

Photothermal, photodynamic and sonodynamic cancer therapies offer opportunities for precise tumor ablation and reduce side effects. The cyclic guanylate adenylate synthase-stimulator of interferon genes (cGAS-STING) pathway has been considered a potential target to stimulate the immune system in patients and achieve a sustained immune response. Combining photothermal, photodynamic and sonodynamic therapies with cGAS-STING agonists represents a newly developed cancer treatment demonstrating noticeable innovation in its impact on the immune system. Recent reviews have concentrated on diverse materials and their function in cancer therapy. In this review, we focus on the molecular mechanism of photothermal, photodynamic and sonodynamic cancer therapies and the connected role of cGAS-STING agonists in treating cancer.

Magnetothermal-activated gene editing strategy for enhanced tumor cell apoptosis

Precise and effective initiation of the apoptotic mechanism in tumor cells is one of the most promising approaches for the treatment of solid tumors. However, current techniques such as high-temperature ablation or gene editing suffer from the risk of damage to adjacent normal tissues. This study proposes a magnetothermal-induced CRISPR-Cas9 gene editing system for the targeted knockout of HSP70 and BCL2 genes, thereby enhancing tumor cell apoptosis. The magnetothermal nanoparticulate platform is composed of superparamagnetic ZnCoFe2O4@ZnMnFe2O4 nanoparticles and the modified polyethyleneimine (PEI) and hyaluronic acid (HA) on the surface, on which plasmid DNA can be effectively loaded. Under the induction of a controllable alternating magnetic field, the mild magnetothermal effect (42℃) not only triggers dual-genome editing to disrupt the apoptosis resistance mechanism of tumor cells but also sensitizes tumor cells to apoptosis through the heat effect itself, achieving a synergistic therapeutic effect. This strategy can precisely regulate the activation of the CRISPR-Cas9 system for tumor cell apoptosis without inducing significant damage to healthy tissues, thus providing a new avenue for cancer treatment.

Metal-Organic Framework: Fabrication of Nano Fluorescent Composite Materials and Treatment of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a common malignant tumor originating from liver cells, characterized by complex pathogenesis and limited treatment options such as surgery, chemotherapy, and transplantation. Cisplatin, an effective chemotherapeutic agent, disrupts cancer cell DNA but is hindered by side effects and the need for controlled sustained release to optimize efficacy. Metal-organic frameworks (MOFs) have emerged as promising nanocarriers for precise local drug delivery, reducing required doses and mitigating side effects of chemotherapeutic drugs, thus offering a potential avenue for hepatocellular carcinoma (HCC) treatment. In this research, a rectangular channel MOF (Rumgay H, Ferlay J, Martel C, Georges D, Ibrahim AS, Zheng R, Wei W, Lemmens VEPP, Soerjomataram I (2022) Global, regional and national burden of primary liver cancer by subtype. Eur J Cancer 161:108-118) carrier was synthesized using ligand L as the organic linker coordinated with Cu(II) and I(I). The MOF's structure and fluorescence properties were characterized. Additionally, to enhance substrate biocompatibility, composite carrier materials were prepared by incorporating polylactic acid (PLA) with 1, utilized for cisplatin loading. To evaluate the inhibitory effect of PLA-1@cisplatin on HCC, HepG-2 and Huh-7 HCC cell lines were treated with varying concentrations of the drug for 48 h, and their cell viability was assessed. The results demonstrated a significant dose-dependent reduction in cell viability of both HepG-2 and Huh-7 cells. To explore the potential inhibitory mechanism of PLA-1@cisplatin on HCC, the mRNA levels of GADD45A and NACC1 in HepG-2 and Huh-7 cells post-treatment were measured. GADD45A expression, initially low in HCC cells, was significantly upregulated after drug treatment, while NACC1, typically highly expressed in HCC, showed a significant decrease in mRNA levels with increasing concentrations of PLA-1@cisplatin. These findings indicate that PLA-1@cisplatin effectively upregulates GADD45A expression and downregulates NACC1 expression. Overall, the developed cisplatin-loaded nanoparticle system holds promise for HCC treatment by reducing chemotherapy side effects and enhancing drug efficacy.

Natural Killer-Based Therapy: A Prospective Thought for Cancer Treatment Related to Diversified Drug Delivery Pathways

Immunotherapy has been a research hotspot due to its low side effects, long-lasting efficacy, and wide anti-tumor spectrum. Recently, NK cell-based immunotherapy has gained broad attention for its unique immunological character of tumor identification and eradication and low risk of graft-versus-host disease and cytokine storm. With the cooperation of a drug delivery system (DDS), NK cells activate tumoricidal activity by adjusting the balance of the activating and inhibitory signals on their surface after drug-loaded DDS administration. Moreover, NK cells or NK-derived exosomes can also be applied as drug carriers for distinct modification to promote NK activation and exert anti-tumor effects. In this review, we first introduce the source and classification of NK cells and describe the common activating and inhibitory receptors on their surface. Then, we summarize the strategies for activating NK cells in vivo through various DDSs. Finally, the application prospects of NK cells in tumor immunotherapy are also discussed.

Functional hydrogels for hepatocellular carcinoma: therapy, imaging, and in vitro model

Hepatocellular carcinoma (HCC) is among the most common malignancies worldwide and is characterized by high rates of morbidity and mortality, posing a serious threat to human health. Interventional embolization therapy is the main treatment against middle- and late-stage liver cancer, but its efficacy is limited by the performance of embolism, hence the new embolic materials have provided hope to the inoperable patients. Especially, hydrogel materials with high embolization strength, appropriate viscosity, reliable security and multifunctionality are widely used as embolic materials, and can improve the efficacy of interventional therapy. In this review, we have described the status of research on hydrogels and challenges in the field of HCC therapy. First, various preparation methods of hydrogels through different cross-linking methods are introduced, then the functions of hydrogels related to HCC are summarized, including different HCC therapies, various imaging techniques, in vitro 3D models, and the shortcomings and prospects of the proposed applications are discussed in relation to HCC. We hope that this review is informative for readers interested in multifunctional hydrogels and will help researchers develop more novel embolic materials for interventional therapy of HCC.

Remote Control of Energy Transformation-Based Cancer Imaging and Therapy

Cancer treatment requires precise tumor-specific targeting at specific sites that allows for high-resolution diagnostic imaging and long-term patient-tailorable cancer therapy; while, minimizing side effects largely arising from non-targetability. This can be realized by harnessing exogenous remote stimuli, such as tissue-penetrative ultrasound, magnetic field, light, and radiation, that enable local activation for cancer imaging and therapy in deep tumors. A myriad of nanomedicines can be efficiently activated when the energy of such remote stimuli can be transformed into another type of energy. This review discusses the remote control of energy transformation for targetable, efficient, and long-term cancer imaging and therapy. Such ultrasonic, magnetic, photonic, radiative, and radioactive energy can be transformed into mechanical, thermal, chemical, and radiative energy to enable a variety of cancer imaging and treatment modalities. The current review article describes multimodal energy transformation where a serial cascade or multiple types of energy transformation occur. This review includes not only mechanical, chemical, hyperthermia, and radiation therapy but also emerging thermoelectric, pyroelectric, and piezoelectric therapies for cancer treatment. It also illustrates ultrasound, magnetic resonance, fluorescence, computed tomography, photoluminescence, and photoacoustic imaging-guided cancer therapies. It highlights afterglow imaging that can eliminate autofluorescence for sustained signal emission after the excitation.

Water-filtered infrared A radiation hyperthermia combined with immunotherapy for advanced gastrointestinal tumours

This study pioneered the use of WIRA whole-body infrared hyperthermia combined with ICI therapy to treat GIT and verified the feasibility and safety of HIT. The final results showed a DCR of 55.6%, with a median PFS of 53.5 days, median OS of 134 days, and an irAE incidence of 22.2%. Therefore, we believe that HIT can exert multiple synergistic sensitisation effects, thereby providing clinical benefits to patients with advanced GITs, increasing overall safety, and improving patients' QOL.

Transition Metal Oxide Nanomaterials: New Weapons to Boost Anti-Tumor Immunity Cycle

Semiconductor nanomaterials have emerged as a significant factor in the advancement of tumor immunotherapy. This review discusses the potential of transition metal oxide (TMO) nanomaterials in the realm of anti-tumor immune modulation. These binary inorganic semiconductor compounds possess high electron mobility, extended ductility, and strong stability. Apart from being primary thermistor materials, they also serve as potent agents in enhancing the anti-tumor immunity cycle. The diverse metal oxidation states of TMOs result in a range of electronic properties, from metallicity to wide-bandgap insulating behavior. Notably, titanium oxide, manganese oxide, iron oxide, zinc oxide, and copper oxide have garnered interest due to their presence in tumor tissues and potential therapeutic implications. These nanoparticles (NPs) kickstart the tumor immunity cycle by inducing immunogenic cell death (ICD), prompting the release of ICD and tumor-associated antigens (TAAs) and working in conjunction with various therapies to trigger dendritic cell (DC) maturation, T cell response, and infiltration. Furthermore, they can alter the tumor microenvironment (TME) by reprogramming immunosuppressive tumor-associated macrophages into an inflammatory state, thereby impeding tumor growth. This review aims to bring attention to the research community regarding the diversity and significance of TMOs in the tumor immunity cycle, while also underscoring the potential and challenges associated with using TMOs in tumor immunotherapy.

Intracellular magnetic hyperthermia reverses sorafenib resistance in hepatocellular carcinoma through its action on signaling pathways

Sorafenib, a first-line drug for advanced hepatocellular carcinoma (HCC), unfortunately encounters resistance in most patients, leading to disease progression. Traditional approaches to counteract this resistance, particularly those targeting the RAF-MEK-ERK pathway, often face clinical feasibility limitations. Magnetic hyperthermia (MH), unlike conventional thermal therapies, emerges as a promising alternative. It uniquely combines magnetothermal effects with an increase in reactive oxygen species (ROS). This study found the potential of intracellular MH enhanced the efficacy of sorafenib, increased cellular sensitivity to sorafenib, and reversed sorafenib resistance by inhibiting the RAF-MEK-ERK pathway in an ROS-dependent manner in a sorafenib-resistant HCC cell. Further, in a sorafenib-resistant HCC mouse model, MH significantly sensitized tumors to sorafenib therapy, resulting in inhibited tumor growth and improved survival rates. This presents a promising strategy to overcome sorafenib resistance in HCC, potentially enhancing therapeutic outcomes for patients with this challenging condition.

Zinc Doping Engineering in ZnxFe3-xO4 Heterostructures for Enhancing Photodynamic Therapy in the Near-Infrared-II Region

Currently, photodynamic therapy (PDT) is restricted by the laser penetration depth. Except for PDT at 1064 nm wavelength excitation, the development of other NIR-II-activated nanomaterials with a higher response depth is still hindered and rarely reported in the literature. To overcome these problems, we fabricated a nanoplatform with heterostructures that generate reactive oxygen species (ROS) and ferrite nanoparticles under a high concentration of zinc doping (ZnxFe3-xO4 NPs), which can achieve oxidative damage of tumor cells under near-infrared (NIR) illumination. The recombination of photoelectrons and holes has been markedly inhibited due to the formation of heterostructures in the interfaces, thus greatly enhancing the capability for ROS and oxygen production by modulating the single-component doping content. The efficiency of PDT was verified by in vivo and in vitro assays under NIR light. Our results revealed that NIR-II (1208 nm) light irradiation of ZnxFe3-xO4 NPs exerted a remarkable antitumor activity, superior to NIR-I light (808 nm). More importantly, the reported ZnxFe3-xO4 NPs strategy provides an opportunity for the success of comparison with light in the first and second near-infrared regions.

Exosome-Inhibiting Polymeric Sonosensitizer for Tumor-Specific Sonodynamic Immunotherapy

Combination cancer immunotherapy based on electromagnetic energy and immunotherapy shows potent anti-cancer efficacy. However, as a factor that mediates tumor metastasis and immune suppression, the impact of tumor exosomes on therapy under electromagnetic energy stimulation remains unclear. Herein, findings indicate that sonodynamic therapy (SDT) increases serum exosome levels by inducing apoptotic exosomes and loosening the tumor extracellular matrix, promoting lung metastasis. To address this problem, an exosome-inhibiting polymeric sonosensitizer (EIPS) selectively inhibiting tumor exosome generation in response to the tumor biomarker is synthesized. EIPS consists of a semiconducting polymer backbone capable of inducing SDT and a poly(ethylene glycol) layer conjugated with a tumor-specific enzyme-responsive exosome inhibitor prodrug. After being cleaved by tumor Cathepsin B, EIPS releases active exosome inhibitors, preventing tumor exosome-mediated immune suppression and lung metastasis. As a result, EIPS elicits robust antitumor effects through the synergistic effect of SDT and tumor exosome inhibition, completely preventing lung metastasis and establishing a long-term immune memory effect. This is the first example showing that combining SDT with tumor-specific exosome inhibition can elicit a potent immune response without the help of typical immune agonists.

Mild magnetic hyperthermia-activated immuno-responses for primary bladder cancer therapy

Surgical intervention followed by chemotherapy is the principal treatment strategy for bladder cancer, which is hindered by significant surgical risks, toxicity from chemotherapy, and high rates of recurrence after surgery. In this context, a novel approach using mild magnetic hyperthermia therapy (MHT) for bladder cancer treatment through the intra-bladder delivery of magnetic nanoparticles is presented for the first time. This method overcomes the limitations of low magnetic thermal efficiency, inadequate tumor targeting, and reduced therapeutic effectiveness associated with the traditional intravenous administration of magnetic nanoparticles. Core-shell Zn-CoFe2O4@Zn-MnFe2O4 (MNP) nanoparticles were developed and further modified with hyaluronic acid (HA) to enhance their targeting ability toward tumor cells. The application of controlled mild MHT using MNP-HA at temperatures of 43-44 °C successfully suppressed the proliferation of bladder tumor cells and tumor growth, while also decreasing the expression levels of heat shock protein 70 (HSP70). Crucially, this therapeutic approach also activated the body's innate immune response involving macrophages, as well as the adaptive immune responses of dendritic cells (DCs) and T cells, thereby reversing the immunosuppressive environment of the bladder tumor and effectively reducing tumor recurrence. This study uncovers the potential immune-activating mechanism of mild MHT in the treatment of bladder cancer and confirms the effectiveness and safety of this strategy, indicating its promising potential for the clinical management of bladder cancer with a high tendency for relapse.

Magnetic nanoparticles: An emerging nanomedicine for cancer immunotherapy

Cancer immunotherapy is a revolutionised strategy that strikingly improves cancer treatment in recent years. However, like other therapeutic modalities, immunotherapy faces several challenges and limitations. Many methods have been developed to overcome those limitations; thus, nanomedicine is one of the emerging fields with a highly promising application. Magnetite nanoparticles (MNPs) have long been used for medical applications, for example, as a contrast medium, and are being investigated as a tool for boosting and synergizing the effects of immunotherapy. With known physicochemical properties and the interaction with the surroundings in biological systems, MNPs are used to improve the efficacy of immunotherapy in both cell-based and antibody-based treatment. This chapter reviews and discusses state-of-the-art MNPs as a tool to advance cancer immunotherapy as well as its limitations that need further investigation for a better therapeutic outcome in preclinical and clinical settings.

NIR and magnetism dual-response multi-core magnetic vortex nanoflowers for boosting magneto-photothermal cancer therapy

Due to the relatively low efficiency of magnetic hyperthermia and photothermal conversion, it is rather challenging for magneto-photothermal nanoagents to be used as an effective treatment during tumor hyperthermal therapy. The advancement of magnetic nanoparticles exhibiting a vortex-domain structure holds great promise as a viable strategy to enhance the application performance of conventional magnetic nanoparticles while retaining their inherent biocompatibility. Here, we report the development of Mn0.5Zn0.5Fe2O4 nanoflowers with ellipsoidal magnetic cores, and show them as effective nanoagents for magneto-photothermal synergistic therapy. Comparative studies were conducted on the heating performance of anisometric Mn0.5Zn0.5Fe2O4 (MZF) nanoparticles, including nanocubes (MZF-C), hollow spheres (MZF-HS), nanoflowers consisting of ellipsoidal magnetic cores (MZF-NFE), and nanoflowers consisting of needle-like magnetic cores (MZF-NFN). MZF-NFE exhibits an intrinsic loss parameter (ILP) of up to 15.3 N h m2 kg-1, which is better than that of commercial equivalents. Micromagnetic simulations reveal the magnetization configurations and reversal characteristics of the various MZF shapes. Additionally, all nanostructures displayed a considerable photothermal conversion efficiency rate of more than 18%. Our results demonstrated that by combining the dual exposure of MHT and PTT for hyperthermia treatments induced by MZF-NFE, BT549, MCF-7, and 4T1 cell viability can be significantly decreased by ∼95.7% in vitro.

Ca2+ Overload Decreased Cellular Viability in Magnetic Hyperthermia without a Macroscopic Temperature Rise

Magnetic hyperthermia is a crucial medical engineering technique for treating diseases, which usually uses alternating magnetic fields (AMF) to interplay with magnetic substances to generate heat. Recently, it has been found that in some cases, there is no detectable temperature increment after applying an AMF, which caused corresponding effects surprisingly. The mechanisms involved in this phenomenon are not yet fully understood. In this study, we aimed to explore the role of Ca2+ overload in the magnetic hyperthermia effect without a perceptible temperature rise. A cellular system expressing the fusion proteins TRPV1 and ferritin was prepared. The application of an AMF (518 kHz, 16 kA/m) could induce the fusion protein to release a large amount of iron ions, which then participates in the production of massive reactive oxygen radicals (ROS). Both ROS and its induced lipid oxidation enticed the opening of ion channels, causing intracellular Ca2+ overload, which further led to decreased cellular viability. Taken together, Ca2+ overload triggered by elevated ROS and the induced oxidation of lipids contributes to the magnetic hyperthermia effect without a perceptible temperature rise. These findings would be beneficial for expanding the application of temperature-free magnetic hyperthermia, such as in cellular and neural regulation, design of new cancer treatment methods.

Study of biopolymer encapsulated Eu doped Fe3O4 nanoparticles for magnetic hyperthermia application

An exciting prospect in the field of magnetic fluid hyperthermia (MFH) has been the integration of noble rare earth elements (Eu) with biopolymers (chitosan/dextran) that have optimum structures to tune specific effects on magnetic nanoparticles (NPs). However, the heating efficiency of MNPs is primarily influenced by their magnetization, size distribution, magnetic anisotropy, dipolar interaction, amplitude, and frequency of the applied field, the MNPs with high heating efficiency are still challenging. In this study, a comprehensive experimental analysis has been conducted on single-domain magnetic nanoparticles (SDMNPs) for evaluating effective anisotropy, assessing the impact of particle-intrinsic factors and experimental conditions on self-heating efficiency in both noninteracting and interacting systems, with a particular focus on the dipolar interaction effect. The study successfully reconciles conflicting findings on the interaction effects in the agglomeration and less agglomerated arrangements for MFH applications. The results suggest that effective control of dipolar interactions can be achieved by encapsulating Chitosan/Dextran in the synthesized MNPs. The lower dipolar interactions successfully tune the self-heating efficiency and hold promise as potential candidates for MFH applications.

Nanomedicine Remodels Tumor Microenvironment for Solid Tumor Immunotherapy

Although immunotherapy is relatively effective in treating hematological malignancies, their efficacy against solid tumors is still suboptimal or even noneffective presently. Compared to hematological cancers, solid tumors exhibit strikingly different immunosuppressive microenvironment, severely deteriorating the efficacy of immunotherapy: (1) chemical features such as hypoxia and mild acidity suppress the activity of immune cells, (2) the pro-tumorigenic domestication of immune cells in the microenvironment within the solid tumors further undermines the effectiveness of immunotherapy, and (3) the dense physical barrier of solid tumor tissues prevents the effective intratumoral infiltration and contact killing of active immune cells. Therefore, we believe that reversing the immunosuppressive microenvironment are of critical priority for the immunotherapy against solid tumors. Due to their unique morphologies, structures, and compositions, nanomedicines have become powerful tools for achieving this goal. In this Perspective, we will first briefly introduce the immunosuppressive microenvironment of solid tumors and then summarize the most recent progresses in nanomedicine-based immunotherapy for solid tumors by remodeling tumor immune-microenvironment in a comprehensive manner. It is highly expected that this Perspective will aid in advancing immunotherapy against solid tumors, and we are highly optimistic on the future development in this burgeoning field.

A novel ternary magnetic nanobiocomposite based on tragacanth-silk fibroin hydrogel for hyperthermia and biological properties

This study involves the development of a new nanocomposite material for use in biological applications. The nanocomposite was based on tragacanth hydrogel (TG), which was formed through cross-linking of Ca2+ ions with TG polymer chains. The utilization of TG hydrogel and silk fibroin as natural compounds has enhanced the biocompatibility, biodegradability, adhesion, and cell growth properties of the nanobiocomposite. This advancement makes the nanobiocomposite suitable for various biological applications, including drug delivery, wound healing, and tissue engineering. Additionally, Fe3O4 magnetic nanoparticles were synthesized in situ within the nanocomposite to enhance its hyperthermia efficiency. The presence of hydrophilic groups in all components of the nanobiocomposite allowed for good dispersion in water, which is an important factor in increasing the effectiveness of hyperthermia cancer therapy. Hemolysis and 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assays were conducted to evaluate the safety and efficacy of the nanobiocomposite for in-vivo applications. Results showed that even at high concentrations, the nanobiocomposite had minimal hemolytic effects. Finally, the hyperthermia application of the hybrid scaffold was evaluated, with a maximum SAR value of 41.2 W/g measured in the first interval.

Nonmetallic graphite for tumor magnetic hyperthermia therapy

Magnetic hyperthermia therapy (MHT) has garnered immense interest due to its exceptional spatiotemporal specificity, minimal invasiveness and remarkable tissue penetration depth. Nevertheless, the limited magnetothermal heating capability and the potential toxicity of metal ions in magnetic materials based on metallic elements significantly impede the advancement of MHT. Herein, we introduce the concept of nonmetallic materials, with graphite (Gra) as a proof of concept, as a highly efficient and biocompatible option for MHT of tumors in vivo for the first time. The Gra exhibits outstanding magnetothermal heating efficacy owing to the robust eddy thermal effect driven by its excellent electrical conductivity. Furthermore, being composed of carbon, Gra offers superior biocompatibility as carbon is an essential element for all living organisms. Additionally, the Gra boasts customizable shapes and sizes, low cost, and large-scale production capability, facilitating reproducible and straightforward manufacturing of various Gra implants. In a mouse tumor model, Gra-based MHT successfully eliminates the tumors at an extremely low magnetic field intensity, which is less than one-third of the established biosafety threshold. This study paves the way for the development of high-performance magnetocaloric materials by utilizing nonmetallic materials in place of metallic ones burdened with inherent limitations.

Magnetic Particle Imaging: From Tracer Design to Biomedical Applications in Vasculature Abnormality

Magnetic particle imaging (MPI) is an emerging non-invasive tomographic technique based on the response of magnetic nanoparticles (MNPs) to oscillating drive fields at the center of a static magnetic gradient. In contrast to magnetic resonance imaging (MRI), which is driven by uniform magnetic fields and projects the anatomic information of the subjects, MPI directly tracks and quantifies MNPs in vivo without background signals. Moreover, it does not require radioactive tracers and has no limitations on imaging depth. This article first introduces the basic principles of MPI and important features of MNPs for imaging sensitivity, spatial resolution, and targeted biodistribution. The latest research aiming to optimize the performance of MPI tracers is reviewed based on their material composition, physical properties, and surface modifications. While the unique advantages of MPI have led to a series of promising biomedical applications, recent development of MPI in investigating vascular abnormalities in cardiovascular and cerebrovascular systems, and cancer are also discussed. Finally, recent progress and challenges in the clinical translation of MPI are discussed to provide possible directions for future research and development.

Nanomedicines for reversing immunosuppressive microenvironment of hepatocellular carcinoma

Although immunotherapeutic strategies such as immune checkpoint inhibitors (ICIs) have gained promising advances, their limited efficacy and significant toxicity remain great challenges for hepatocellular carcinoma (HCC) immunotherapy. The tumor immunosuppressive microenvironment (TIME) with insufficient T-cell infiltration and low immunogenicity accounts for most HCC patients' poor response to ICIs. Worse still, the current immunotherapeutics without precise delivery may elicit enormous autoimmune side effects and systemic toxicity in the clinic. With a better understanding of the TIME in HCC, nanomedicines have emerged as an efficient strategy to achieve remodeling of the TIME and superadditive antitumor effects via targeted delivery of immunotherapeutics or multimodal synergistic therapy. Based on the typical characteristics of the TIME in HCC, this review summarizes the recent advancements in nanomedicine-based strategies for TIME-reversing HCC treatment. Additionally, perspectives on the awaiting challenges and opportunities of nanomedicines in modulating the TIME of HCC are presented. Acquisition of knowledge of nanomedicine-mediated TIME reversal will provide researchers with a better opportunity for clinical translation of HCC immunotherapy.

Application of Nanoparticles for Magnetic Hyperthermia for Cancer Treatment-The Current State of Knowledge

Hyperthermia (HT) is an anti-cancer therapy commonly used with radio and chemotherapies based on applying heat (39-45 °C) to inhibit tumor growth. However, controlling heat towards tumors and not normal tissues is challenging. Therefore, nanoparticles (NPs) are used in HT to apply heat only to tumor tissues to induce DNA damage and the expression of heat shock proteins, which eventually result in apoptosis. The aim of this review article is to summarize recent advancements in HT with the use of magnetic NPs to locally increase temperature and promote cell death. In addition, the recent development of nanocarriers as NP-based drug delivery systems is discussed. Finally, the efficacy of HT combined with chemotherapy, radiotherapy, gene therapy, photothermal therapy, and immunotherapy is explored.

Intracellular Magnetic Hyperthermia Enables Concurrent Down-Regulation of CD47 and SIRPα To Potentiate Antitumor Immunity

Harnessing the potential of tumor-associated macrophages (TAMs) to engulf tumor cells offers promising avenues for cancer therapy. Targeting phagocytosis checkpoints, particularly the CD47-signal regulatory protein α (SIRPα) axis, is crucial for modulating TAM activity. However, single checkpoint inhibition has shown a limited efficacy. In this study, we demonstrate that ferrimagnetic vortex-domain iron oxide (FVIO) nanoring-mediated magnetic hyperthermia effectively suppresses the expression of CD47 protein on Hepa1-6 tumor cells and SIRPα receptor on macrophages, which disrupts CD47-SIRPα interaction. FVIO-mediated magnetic hyperthermia also induces immunogenic cell death and polarizes TAMs toward M1 phenotype. These changes collectively bolster the phagocytic ability of macrophages to eliminate tumor cells. Furthermore, FVIO-mediated magnetic hyperthermia concurrently escalates cytotoxic T lymphocyte levels and diminishes regulatory T cell levels. Our findings reveal that magnetic hyperthermia offers a novel approach for dual down-regulation of CD47 and SIRPα, reshaping the tumor microenvironment to stimulate immune responses, culminating in significant antitumor activity.