Nanobiotechnology-enabled energy utilization elevation for augmenting minimally-invasive and noninvasive oncology thermal ablation

Nanomedicine-unlocked radiofrequency dynamic therapy dampens incomplete radiofrequency ablation-arised immunosuppression to suppress cancer relapse

Incomplete radiofrequency ablation (iRFA) not only leaves residual tumor, but also render the residual tumor highly self-adaptable and immunosuppressive, consequently expediting residual tumor progression including relapse. To address it, radiofrequency dynamic therapy (RFDT) with identical trigger (namely radiofrequency) has been established and enabled by polyethylene glycol (PEG)-modified Fe-based single atom nanozyme (P@Fe SAZ). P@Fe SAZ can respond to radiofrequency field to produce reactive oxygen species (ROS), attaining the nanomedicine-unlocked low-temperature RFDT. Systematic experiments reveal that ROS further remodels iRFA-potentiated immunosuppressive microenvironment, e.g., expediting tumor-associated macrophages (TAMs) polarization into TAMs-M1, rejecting the intratumoral infiltrations of myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs). Coincidently, they have been demonstrated to stimulate dendritic cells (DCs) maturation and encourage the proliferations and infiltrations of effector T cells, consequently boosting anti-tumor immune responses and attenuating iRFA-enhanced plasticity, treatment resistance and self-adaptation of residual hepatocellular carcinoma (HCC) after iRFA. Thanks to them, such a nanomedicine-unlocked low-temperature RFDT exerts powerful actions on residual HCC model after iRFA with rapid expansion inhibition, relapse repression, survival prolongation, apoptosis promotion, etc. This low-temperature RFDT opens a window to address the iRFA-enhanced immunosuppression.

Tissue Ablation: Applications and Perspectives

Tissue ablation techniques have emerged as a critical component of modern medical practice and biomedical research, offering versatile solutions for treating various diseases and disorders. Percutaneous ablation is minimally invasive and offers numerous advantages over traditional surgery, such as shorter recovery times, reduced hospital stays, and decreased healthcare costs. Intra-procedural imaging during ablation also allows precise visualization of the treated tissue while minimizing injury to the surrounding normal tissues, reducing the risk of complications. Here, the mechanisms of tissue ablation and innovative energy delivery systems are explored, highlighting recent advancements that have reshaped the landscape of clinical practice. Current clinical challenges related to tissue ablation are also discussed, underlining unmet clinical needs for more advanced material-based approaches to improve the delivery of energy and pharmacology-based therapeutics.

Metal-organic frameworks as candidates for tumor sonodynamic therapy: Designable structures for targeted multifunctional transformation

Sonodynamic therapy (SDT), utilizing ultrasound (US) as the trigger, has gained popularity recently as a therapeutic approach with significant potential for treating various diseases. Metal-organic frameworks (MOFs), characterized by structural flexibility, are prominently emerging in the SDT realm as an innovative type of sonosensitizer, offering functional tunability and biocompatibility. However, due to the inherent limitations of MOFs, such as low reactivity to reactive oxygen species and challenges posed by the complex tumor microenvironment, MOF-based sonosensitizers with singular functions are unable to demonstrate the desired therapeutic efficacy and may pose risks of toxicity, limiting their biological applications to superficial tissues. MOFs generally possess distinctive crystalline structures and properties, and their controlled coordination environments provide a flexible platform for exploring structure-effect relationships and guiding the design and development of MOF-based nanomaterials to unlock their broader potential in biological fields. The primary focus of this paper is to summarize cases involving the modification of different MOF materials and the innovative strategies developed for various complex conditions. The paper outlines the diverse application areas of functionalized MOF-based sonosensitizers in tumor synergistic therapies, highlighting the extensive prospects of SDT. Additionally, challenges confronting SDT are briefly summarized to stimulate increased scientific interest in the practical application of MOFs and the successful clinical translation of SDT. Through these discussions, we strive to foster advancements that lead to early-stage clinical benefits for patients. STATEMENT OF SIGNIFICANCE: 1. An overview for the progresses in SDT explored from a novel and fundamental perspective. 2. Different modification strategies to improve the MOFs-mediated SDT efficacy are provided. 3. Guidelines for the design of multifunctional MOFs-based sonosensitizers are offered. 4. Powerful tumor ablation potential is reflected in SDT-led synergistic therapies. 5. Future challenges in the field of MOFs-based SDT in clinical translation are suggested.

A Distinctive Insight into Inorganic Sonosensitizers: Design Principles and Application Domains

Sonodynamic therapy (SDT) as a promising non-invasive anti-tumor means features the preferable penetration depth, which nevertheless, usually can't work without sonosensitizers. Sonosensitizers produce reactive oxygen species (ROS) in the presence of ultrasound to directly kill tumor cells, and concurrently activate anti-tumor immunity especially after integration with tumor microenvironment (TME)-engineered nanobiotechnologies and combined therapy. Current sonosensitizers are classified into organic and inorganic ones, and current most reviews only cover organic sonosensitizers and highlighted their anti-tumor applications. However, there have few specific reviews that focus on inorganic sonosensitizers including their design principles, microenvironment regulation, etc. In this review, inorganic sonosensitizers are first classified according to their design rationales rather than composition, and the action rationales and underlying chemistry features are highlighted. Afterward, what and how TME is regulated based on the inorganic sonosensitizers-based SDT nanoplatform with an emphasis on the TME targets-engineered nanobiotechnologies are elucidated. Additionally, the combined therapy and their applications in non-cancer diseases are also outlined. Finally, the setbacks and challenges, and proposed the potential solutions and future directions is pointed out. This review provides a comprehensive and detailed horizon on inorganic sonosensitizers, and will arouse more attentions on SDT.

Achieving Complete Tumor Clearance: A Minimalist Manganese Hydrogel for Magnetic Resonance Imaging-Guided Synergetic Microwave Ablation and Chemodynamic Therapy

The combination of microwave ablation (MWA) and chemodynamic therapy (CDT) presents a promising strategy for complete eradication of residual tumor after MWA. However, it remains challenging and urgent to develop a facile, biocompatible, and imaging-guided platform for the achievement of this goal. Herein, a minimalist manganese hydrogel (ALG-Mn hydrogel) is proposed for synergistic MWA and CDT to completely eradicate tumor in vivo. The ALG-Mn hydrogel is prepared using a simple mixing method and exhibits excellent syringeability, remarkable microwave sensitivity, and potent Fenton-like activity. By assisting in MWA procedures, the ALG-Mn hydrogel enables both elimination of primary tumor mass through enhanced MWA efficacy and eradication of potential residual tumor tissues via robust CDT. This approach achieves complete tumor clearance without additional drug loading. Furthermore, the paramagnetic Mn2+ component allows real-time dynamic visualization of the ALG-Mn hydrogel at the tumor site via magnetic resonance imaging. To the best of knowledge, the proposed ALG-Mn hydrogel represents the minimalist biocompatible platform for imaging-guided synergistic MWA and CDT toward achieving complete tumor clearance.

Recent Progress in Phage-Based Nanoplatforms for Tumor Therapy

Nanodrug delivery systems have demonstrated a great potential for tumor therapy with the development of nanotechnology. Nonetheless, traditional drug delivery systems are faced with issues such as complex synthetic procedures, low reproducibility, nonspecific distribution, impenetrability of biological barrier, systemic toxicity, etc. In recent years, phage-based nanoplatforms have attracted increasing attention in tumor treatment for their regular structure, fantastic carrying property, high transduction efficiency and biosafety. Notably, therapeutic or targeting peptides can be expressed on the surface of the phages through phage display technology, enabling the phage vectors to possess multifunctions. As a result, the drug delivery efficiency on tumor will be vastly improved, thereby enhancing the therapeutic efficacy while reducing the side effects on normal tissues. Moreover, phages can overcome the hindrance of biofilm barrier to elicit antitumor effects, which exhibit great advantages compared with traditional synthetic drug delivery systems. Herein, this review not only summarizes the structure and biology of the phages, but also presents their potential as prominent nanoplatforms against tumor in different pathways to inspire the development of effective nanomedicine.

Magnetic Bimetallic Heterointerface Nanomissiles with Enhanced Microwave Absorption for Microwave Thermal/Dynamics Therapy of Breast Cancer

Microwave thermotherapy (MWT) has shown great potential in cancer treatment due to its deep tissue penetration and minimally invasive nature. However, the poor microwave absorption (MA) properties of the microwave thermal sensitizer in the medical frequency band significantly limit the thermal effect of MWT and then weaken the therapeutic efficacy. In this paper, a Ni-based multilayer heterointerface nanomissile of MOFs-Ni-Ru@COFs (MNRC) with improved MA performance in the desired frequency band via introducing magnetic loss and dielectric loss is developed for MWT-based treatment. The loading of the Ni nanoparticle in MNRC mediates the magnetic loss, introducing the MA in the medical frequency band. The heterointerface formed in the MNRC by nanoengineering induces significant interfacial polarization, increasing the dielectric loss and then enhancing the generated MA performance. Moreover, MNRC with the strong MA performance in the desired frequency range not only enhances the MW thermal effect of MWT but also facilitates the electron and energy transfer, generating reactive oxygen species (ROS) at tumor sites to mediate microwave dynamic therapy (MDT). The strategy of strengthening the MA performance of the sensitizer in the medical frequency band to improve MWT-MDT provides a direction for expanding the clinical application of MWT in tumor treatment.

Macrophage-inherited exosome excise tumor immunosuppression to expedite immune-activated ferroptosis

BACKGROUND

Immunosuppressive tumor microenvironment (ITM) remains an obstacle that jeopardizes clinical immunotherapy.

METHODS

To address this concern, we have engineered an exosome inherited from M1-pheototype macrophages, which thereby retain functions and ingredients of the parent M1-phenotype macrophages. The delivered RSL3 that serves as a common ferroptosis inducer can reduce the levels of ferroptosis hallmarkers (eg, glutathione and glutathione peroxidase 4), break the redox homeostasis to magnify oxidative stress accumulation, promote the expression of ferroptosis-related proteins, and induce robust ferroptosis of tumor cells, accompanied with which systematic immune response activation can bbe realized. M1 macrophage-derived exosomes can inherit more functions and genetic substances than nanovesicles since nanovesicles inevitably suffer from substance and function loss caused by extrusion-arised structural damage.

RESULTS

Inspired by it, spontaneous homing to tumor and M2-like macrophage polarization into M1-like ones are attained, which not only significantly magnify oxidative stress but also mitigate ITM including M2-like macrophage polarization and regulatory T cell decrease, and regulate death pathways.

CONCLUSIONS

All these actions accomplish a synergistic antitumor enhancement against tumor progression, thus paving a general route to mitigate ITM, activate immune responses, and magnify ferroptosis.

Extracellular Matrix Viscosity Reprogramming by In Situ Au Bioreactor-Boosted Microwavegenetics Disables Tumor Escape in CAR-T Immunotherapy

Incomplete microwave ablation (iMWA) caused by uncontrollable heat diffusion enhances the immunosuppressive tumor microenvironment (ITM), consequently disabling the prevalent immune checkpoint blockade-combined immunotherapy against tumor recurrence. Herein, we successfully constructed an intratumorally synthesized Au bioreactor to disperse heat in thermally sensitive hydrogel-filled tumors and improve the energy utilization efficiency, which magnified the effective ablation zone (EAZ), counteracted iMWA, and simultaneously established and enhanced multiple biological process-regulated microwavegenetics. More significantly, we identified the extracellular matrix (ECM) viscosity as a general immune escape "target". After remodeling ECM, including ECM ingredients and cell adhesion molecules, this physical target was blocked by viscosity reprogramming, furnishing an effective tool to regulate the viscosity target. Thereby, such in situ Au bioreactor-enlarged EAZ and enhanced microwavegenetics reversed the immune-desert tumor microenvironment, mitigated ITM, secreted immune cell-attracting chemokines, recruited and polarized various immune cells, and activated or reactivated them like dendritic cells, natural killing cells, M1-type macrophages, and effector CD8+ or CAR-T cells. Contributed by these multiple actions, the in situ oncolytic Au bioreactors evoked CAR-T immunotherapy to acquire a considerably increased inhibition effect against tumor progression and recurrence after iMWA, thus providing a general method to enhance iMWA and CAR-T immunotherapy.

Rational Design of Biomaterials to Potentiate Cancer Thermal Therapy

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

Recent progress in cancer cell membrane-based nanoparticles for biomedical applications

Immune clearance and insufficient targeting have limited the efficacy of existing therapeutic strategies for cancer. Toxic side effects and individual differences in response to treatment have further limited the benefits of clinical treatment for patients. Biomimetic cancer cell membrane-based nanotechnology has provided a new approach for biomedicine to overcome these obstacles. Biomimetic nanoparticles exhibit various effects (e.g., homotypic targeting, prolonging drug circulation, regulating the immune system, and penetrating biological barriers) after encapsulation by cancer cell membranes. The sensitivity and specificity of diagnostic methods will also be improved by utilizing the properties of cancer cell membranes. In this review, different properties and functions of cancer cell membranes are presented. Utilizing these advantages, nanoparticles can exhibit unique therapeutic capabilities in various types of diseases, such as solid tumors, hematological malignancies, immune system diseases, and cardiovascular diseases. Furthermore, cancer cell membrane-encapsulated nanoparticles show improved effectiveness and efficiency in combination with current diagnostic and therapeutic methods, which will contribute to the development of individualized treatments. This strategy has promising clinical translation prospects, and the associated challenges are discussed.

Emerging nanosonosensitizers augment sonodynamic-mediated antimicrobial therapies

With the widespread prevalence of drug-resistant pathogens, traditional antibiotics have limited effectiveness and do not yield the desired outcomes. Recently, alternative antibacterial therapies based on ultrasound (US) have been explored to overcome the crisis of bacterial pathogens. Antimicrobial sonodynamic therapy (aSDT) offers an excellent solution that relies on US irradiation to produce reactive oxygen species (ROS) and achieve antibiotic-free mediated antimicrobial effects. In addition, aSDT possesses the advantage of superior tissue penetrability of US compared to light irradiation, demonstrating great feasibility in treating deep infections. Although existing conventional sonosensitizers can produce ROS for antimicrobial activity, some limitations, such as low penetration rate, nonspecific distribution and poor ROS production under hypoxic conditions, result in suboptimal sterilization in aSDT. Recently, emerging nanosonosensitizers have enormous advantages as high-performance agents in aSDT, which overcome the deficiencies of conventional sonosensitizers as described above. Thus, nanosonosensitizer-mediated aSDT has a bright future for the management of bacterial infections. This review classifies the current available nanosonosensitizers and provides an overview of the mechanisms, biomedical applications, recent advances and perspectives of aSDT.

Application of nanomaterials in combined thermal ablation and immunotherapy for liver tumors

Thermal ablation is one of the important treatments for liver tumors, but the postoperative recurrence rate is high. Thermal ablation has been reported to trigger the release of tumor-associated antigens, which in turn initiates antitumor immune response. However, this anti-tumor immune effect cannot effectively suppress tumor recurrence due to the obstacles of antigen presentation, the formation of tumor-suppressive immune microenvironment, and the hypoxic and hypovascular tumor microenvironment. Therefore, using immunotherapy to enhance the antitumor immune effect after thermal ablation is a potential strategy to improve the prognosis of tumor patients. However, free immune drugs have the disadvantages of poor targeting and short half-life. Nanomaterials have the advantages of strong modifiability, controllable drug ratio, and excellent targeting. Based on the characteristics of the tumor immune microenvironment after thermal ablation, scholars have designed nano-immunopharmaceuticals that can increase the tumor permeability of immune drugs, stimulate antigen presentation, and reshape the tumor immune microenvironment. This review focuses on the role of nanomaterials in tumor ablation combined with immunotherapy for liver tumors.

Oncolytic Impediment/Promotion Balance Disruption by Sonosensitizer-Free Nanoplatforms Unfreezes Autophagy-Induced Resistance to Sonocatalytic Therapy

Autophagy as a double-edged sword features an oncolytic impediment/promotion balance, which manipulates tumor progression. From this perspective, a sonosensitizer-free targeting oncolytic nanoplatform (SFTON) consisting of chloroquine (CQ) and porphyrin-structured metal centers (PMCS) was engineered to break this balance for enhancing antitumor activity. Porphyrin structure retention in a ZIF-8-derived hydrophobic carbon skeleton retained high stability and high sonocatalytic activity, and the hydrophobic carbon skeleton capable of adsorbing air provided cavitation nuclei for further elevating sonocatalytic activity. More significantly, the encapsulated CQ as the autophagy inhibitor reprogrammed autophagy, terminated the autophagy-induced self-protection or self-detoxification, and unfroze the resistances to reactive oxygen species (ROS) therapy associated with ROS accumulation and ROS activity. Systematic experiments reveal the action principles and validate that the induced apoptosis and blockaded autophagosome escalation into the autolysosome were two activated pathways to magnify the antitumor sonocatalytic therapy. Contributed by these actions, the SFTON-unlocked oncolytic impediment/promotion balance disruption strategy acquired considerable antitumor outcomes in vivo and in vitro against liver tumor progression, especially after combining with AS1411-mediated active targeting. This impediment/promotion balance disruption enabled by the SFTON can serve as a general method to elevate ROS-based antitumor activity.

Physical & Chemical Microwave Ablation (MWA) Enabled by Nonionic MWA Nanosensitizers Repress Incomplete MWA-Arised Liver Tumor Recurrence

Ionic liquid (IL)-loaded or metal ions-enriched nanoparticles have been witnessed to assist microwave ablation (MWA) and heighten heat utilization for tumor treatment, which, however, inevitably brings about cell dys-homeostasis and severely endangers normal cells or tissues. In this report, a nonionic MWA sensitizer that encapsulates ethyl formate (EF) and doxorubicin (DOX) in liposomes (EF-DOX-Lips) was constructed to reinforce MWA and combined therapy against incomplete MWA-induced tumor recurrence. EF in EF-DOX-Lips as the nonionic liquid can perform like IL to accelerate energy transformation from electromagnetic energy to heat for strengthening MWA. More significantly, EF metabolite, that is, ethanol, also enables chemical ablation, which further enhances MWA. As well, the EF gasification-enhanced lipid rupture and cavitation can promote DOX delivery into a liver tumor for magnifying MWA & chemotherapy combined therapy. By virtue of these contributions, this nonionic MWA nanosensitizer exerts robust antitumor effects to inhibit tumor proliferation and angiogenesis for repressing tumor growth and recurrence or metastasis via downregulating the Epha2 gene and unconventional PI3K/Akt & MAPK signal pathways that the incomplete MWA activated, which provides an avenue to elevate an MWA-based antitumor outcome.

Recent Advances in Transition-Metal Based Nanomaterials for Noninvasive Oncology Thermal Ablation and Imaging Diagnosis

With the developments of nanobiotechnology and nanomedicine, non-invasive thermal ablation with fewer side effects than traditional tumor treatment methods has received extensive attention in tumor treatment. Non-invasive thermal ablation has the advantages of non-invasiveness and fewer side effects compared with traditional treatment methods. However, the clinical efficiency and biological safety are low, which limits their clinical application. Transition-metal based nanomaterials as contrast agents have aroused increasing interest due to its unique optical properties, low toxicity, and high potentials in tumor diagnosis. Transition-metal based nanomaterials have high conversion efficiency of converting light energy into heat energy, good near-infrared absorption characteristics, which also can targetedly deliver those loaded drugs to tumor tissue, thereby improving the therapeutic effect and reducing the damage to the surrounding normal tissues and organs. This article mainly reviews the synthesis of transition-metal based nanomaterials in recent years, and discussed their applications in tumor thermal ablation and diagnosis, hopefully guiding the development of new transition metal-based nanomaterials in enhancing thermal ablation.

Biomimetic radiosensitizers unlock radiogenetics for local interstitial radiotherapy to activate systematic immune responses and resist tumor metastasis

Background

Similar to other local therapeutic methods, local interstitial radiotherapy (IRT) also suffers from insufficient systematic immune activation, resulting in tumor metastasis.

Results

Mn-based IRT radiosensitizers consisting of ¹³¹I, MnO₂ and bovine serum albumin (BSA) (¹³¹I-MnO₂-BSA) were engineered. Such Mn-based IRT radiosensitizers successfully unlocked radiogenetics to magnify systematic immune responses of local IRT via remodeling hypoxic and immunosuppressive microenvironments and resist tumor metastasis. The MnO₂ in ¹³¹I-MnO₂-BSA caused decomposition of H₂O₂ enriched in tumors to generate O₂ for alleviating hypoxic microenvironment and removing tumor resistances to IRT. Concurrently, hypoxia mitigation by such radiosensitizers-unlocked radiogenetics can effectively remodel immunosuppressive microenvironment associated with regulatory T (Treg) cells and tumor-associated macrophages (TAMs) infiltration inhibition to induce immunogenic cell death (ICD), which, along with hypoxia mitigation, activates systematic immune responses. More intriguingly, ¹³¹I-MnO₂-BSA-enabled radiogenetics can upregulate PD-L1 expression, which allows anti-PD-L1-combined therapy to exert a robust antitumor effect on primary tumors and elicit memory effects to suppress metastatic tumors in both tumor models (4T1 and CT26).

Conclusions

IRT radiosensitizer-unlocked radiogenetics and the corresponding design principle provide a general pathway to address the insufficient systematic immune responses of local IRT.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01324-w.