Recent Advances in Nanomaterial-Assisted Combinational Sonodynamic Cancer Therapy

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

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

Platinum-Titania Schottky Junction as Nanosonosensitizer, Glucose Scavenger, and Tumor Microenvironment-Modulator for Promoted Cancer Treatment

To date, the construction of heterogeneous interfaces between sonosensitizers and other semiconductors or noble metals has aroused increasing attention, owing to an enhanced interface charge transfer, augmented spin-flip, and attenuated activation energy of oxygen. Here, a smart therapeutic nanoplatform is constructed by surface immobilization of glucose oxidase (GOx) onto a TiO₂@Pt Schottky junction. The sonodynamic therapy (SDT) and starvation therapy (ST) mediated by TiO₂@Pt/GOx (TPG) promote systemic tumor suppression upon hypoxia alleviation in tumor microenvironment. The band gap of TiO₂@Pt is outstandingly decreased to 2.9 eV, in contrast to that of pristine TiO₂. The energy structure optimization enables a more rapid generation of singlet oxygen (¹O₂) and hydroxyl radicals (^•OH) by TiO₂@Pt under ultrasound irradiation, resulting from an enhanced separation of hole-electron pair for redox utilization. The tumorous reactive oxygen species (ROS) accumulation and GOx-mediated glucose depletion facilitate oxidative damage and energy exhaustion of cancer cells, both of which can be tremendously amplified by Pt-catalyzed oxygen self-supply. Importantly, the combinatorial therapy triggers intense immunogenetic cell death, which favors a follow-up suppression of distant tumor and metastasis by evoking antitumor immunity. Collectively, this proof-of-concept paradigm provides an insightful strategy for highly efficient SDT/ST, which possesses good clinical potential for tackling cancer.

The crosstalk between sonodynamic therapy and autophagy in cancer

As a noninvasive treatment approach for cancer and other diseases, sonodynamic therapy (SDT) has attracted extensive attention due to the deep penetration of ultrasound, good focusing, and selective irradiation sites. However, intrinsic limitations of traditional sonosensitizers hinder the widespread application of SDT. With the development of nanotechnology, nanoparticles as sonosensitizers or as a vehicle to deliver sonosensitizers have been designed and used to target tissues or tumor cells with high specificity and accuracy. Autophagy is a common metabolic alteration in both normal cells and tumor cells. When autophagy happens, a double-membrane autophagosome with sequestrated intracellular components is delivered and fused with lysosomes for degradation. Recycling these cell materials can promote survival under a variety of stress conditions. Numerous studies have revealed that both apoptosis and autophagy occur after SDT. This review summarizes recent progress in autophagy activation by SDT through multiple mechanisms in tumor therapies, drug resistance, and lipid catabolism. A promising tumor therapy, which combines SDT with autophagy inhibition using a nanoparticle delivering system, is presented and investigated.

Probiotic Engineering and Targeted Sonoimmuno-Therapy Augmented by STING Agonist

Tumor targeting and effective immunomodulation are of critical significance during tumor treatment by sonodynamic therapy (SDT). Herein, the probiotic engineering of the clinically approved sonosensitizer (hematoporphyrin monomethyl ether (HMME)) is reported onto the probiotic bacterium Bifidobacteria Longum (BiL) for sonosensitive bifidobacterium construction (HMME@BiL cells). Based on the hypoxic tropism feature of the strain, effective tumor-targeted sonodynamic therapeutics can be achieved both in vitro and in vivo. To improve the immunological responses against tumor during sonodynamics, a recently-developed stimulator of interferon genes immune agonist SR717 has been employed to improve the anti-tumor immunity with prominent activities, eradicating both primary and metastatic tumors with high efficiency and satisfied biocompatibility. The present work provides a promising paradigm of microbiotic nanomedicine in a sophisticated sonoimmunotherapeutic strategy against malignant tumors.

Specific-Tuning Band Structure in Hetero-Semiconductor Nanorods to Match with Reduction of Oxygen Molecules for Low-Intensity Yet Highly Effective Sonodynamic/Hole Therapy of Tumors

Sonosensitizers-assisted sonodynamic therapy (SDT) has been emerging as a promising treatment for cancers, and yet few specific regulations of band structure of sonosensitizers have been reported in relation to oxygen in tissues. Herein, by a gradient doping technique to modulate the band structure of hetero-semiconductor nanorods, it is found that the reduction potential of band-edge is very critical to reactive oxygen species (ROS) production under low-intensity ultrasound (US) irradiation and particularly, when aligned with the reduction of oxygen, ROS generation is found to be most significantly enhanced. Withal, US-generated oxidation holes are found to be effective in consuming overexpressed glutathione in tumor lesions, which amplifies cellular oxidative stress and finally induces tumor cell death. Moreover, the intrinsic fluorescence property of semiconductors provides imaging capability to illumine tumor area and guide the SDT process. This study demonstrates that the reduction potential state of sonosensitizers is of crucial importance in ROS generation and the proposed reduction potential-tailored hetero-semiconductor nanorods materialize low-intensity US irradiation yet highly effective SDT and synergetic hole therapy of tumors with imaging guidance and reduced radiation injury.

Recent Progress Toward Imaging Application of Multifunction Sonosensitizers in Sonodynamic Therapy

Sonodynamic therapy (SDT) is a rapidly developing non-surgical therapy that initiates sensitizers’ catalytic reaction using ultrasound, showing great potential for cancer treatment due to its high safety and non-invasive nature. In addition, recent research has found that using different diagnostic and therapeutic methods in tandem can lead to better anticancer outcomes. Therefore, as essential components of SDT, sonosensitizers have been extensively explored to optimize their functions and integrate multiple medical fields. The review is based on five years of articles evaluating the combined use of SDT and imaging in treating cancer. By developing multifunctional sonosensitive particles that combine imaging and sonodynamic therapy, we have integrated diagnosis into the treatment of precision medicine applications, improving SDT cell uptake and antitumor efficacy utilizing different tumour models. This paper describes the imaging principle and the results of cellular and animal imaging of the multifunctional sonosensitizers. Efforts are made in this paper to provide data and design references for future SDT combined imaging research and clinical application development and to provide offer suggestions.

Imaging moiety-directed co-assembly for biodegradation control with synchronous four-modal biotracking

The complexity of existing methods for biodegradation control limits the multi-functionality of biomedical materials. It is urgent to develop simple and straightforward strategies to control the biodegradation rate with precise tracking of various parameters in real-time. Here, we show an imaging moiety-directed co-assembly strategy, in which different imaging moieties bearing non-covalent interaction sites are covalently introduced into the poly (D,l-lactic acid) (PDLLA) chain as end groups, followed by alternate non-covalent interactions with polymer chains upon compression molding. This strategy takes advantage of a variety of bonding types (including CH-π, CH-F, etc.) to firmly integrate the PDLLA chains and strongly control the biodegradation rate, making the amorphous prototype degraded much slower than higher-molecular-weight counterparts, and the local inflammatory response is insignificant. On this basis, a synchronous four-modal (X-ray computed tomography + fluorescence + photoacoustics + ultrasound) imaging was achieved on the single entity in vivo, even within a millimeter-scale thick-skin tissue. These imaging signals can precisely correlate the multi parameter variation trend of material mass, volume and molecular weight, signifying that co-assembly can be utilized to develop advanced theranostic systems. SINGLE SENTENCE SUMMARY: We developed an imaging moiety-directed co-assembly strategy to control the biodegradation rate and achieve the synchronization of real-time four-modal imaging in vivo. These imaging signals can precisely correlate the multi-parameter variation trend of material mass, volume and molecular weight, which provided comprehensive biomedical information accessing both qualitatively and quantitatively.

Self-Delivering Nanodrugs Developed via Small-Molecule-Directed Assembly and Macrophage Cloaking for Sonodynamic-Augmented Immunotherapy

The self-delivery of sonosensitizers and immunomodulators to tumor areas, which is highly recommended for enhancing sonodynamic immunotherapy, remains a challenge. Herein, a self-delivering nanodrug (HB-NLG8189, drug loading: ≈100 wt%) is developed by the small-molecule self-assembly of "HB" (a new clinical photosensitizer) and NLG8189 (indoleamine-(2,3)-dioxygenase (IDO) pathway inhibitor) for sonodynamic-augmented immunotherapy; this preparation method ensures the absence of excipient-related toxicity and immunogenicity. To evade immune recognition and prolong the circulation time, the HB-NLG8189 nanodrugs are camouflaged using macrophage cell membranes (MPCMs). The constructed HB-NLG8189@MPCM nanodrugs show an ability to preferentially accumulate within tumors. Upon ultrasound triggering, the HB-NLG8189@MPCM is able to generate reactive oxygen species efficiently for robust sonodynamic therapy; it induces immunogenic cell death, initiates an antitumor immune response to activate tumor-specific effector T cells, and promotes the secretion of inflammatory cytokines. The concomitant delivery of NLG8189 reverses the immunosuppressive tumor microenvironment by restraining IDO-1 activation and the intratumoral infiltration of regulatory T cells. Sonodynamic-augmented immunotherapy with HB-NLG8189@MPCM significantly inhibits the growth of both primary and distant tumors with little systemic toxicity. The biomimetic self-delivery nanodrug provides a promising paradigm for improving sonodynamic immunotherapy.

Metalated covalent organic frameworks: from synthetic strategies to diverse applications

Covalent organic frameworks (COFs) are a class of organic crystalline porous materials discovered in the early 21st century that have become an attractive class of emerging materials due to their high crystallinity, intrinsic porosity, structural regularity, diverse functionality, design flexibility, and outstanding stability. However, many chemical and physical properties strongly depend on the presence of metal ions in materials for advanced applications, but metal-free COFs do not have these properties and are therefore excluded from such applications. Metalated COFs formed by combining COFs with metal ions, while retaining the advantages of COFs, have additional intriguing properties and applications, and have attracted considerable attention over the past decade. This review presents all aspects of metalated COFs, from synthetic strategies to various applications, in the hope of promoting the continued development of this young field.

Flexible CuS-embedded human serum albumin hollow nanocapsules with peroxidase-like activity for synergistic sonodynamic and photothermal cancer therapy

Nanoparticle flexibility is an important parameter in determining cell uptake and tumor accumulation, thus modulating therapeutic efficiency in cancer treatment. Herein, we successfully prepared CuS-embedded human serum albumin hollow nanocapsules (denoted CuS/HSA) by a hard-core-assisted layer-by-layer coating approach. This approach afforded CuS/HSA hollow nanocapsules with controllable shell thickness, tunable flexibility, uniform size (272.9 nm), a large hollow cavity, peroxidase-like activity, excellent photothermal conversion ability, and a high tetra-(4-aminophenyl) porphyrin (TAPP) loading capacity (27.3 wt%). The peroxidase-like activity of the CuS nanoparticles enabled them to overcome tumor hypoxia and augment the sonodynamic therapeutic (SDT) effects and photothermal conversion ability for photothermal therapy (PTT). In vitro experiments showed that the CuS/HSA-TAPP hollow nanocapsules efficiently induced cancer cell apoptosis under US irradiation and cancer cell ablation under laser irradiation, thus facilitating synergistic SDT and PTT. Importantly, the flexibility of the CuS/HSA hollow nanocapsules resulted in significantly enhanced cellular internalization and a longer mean residence time (131.3 h) than their solid counterparts (21.0 h). In a breast tumor model, the flexible CuS/HSA hollow nanocapsules exhibited high tumor accumulation of up to 27.1%. In vivo experiments demonstrated that the flexible CuS/HSA-TAPP hollow nanocapsules effectively eliminated breast tumors via the synergistic effect of SDT and PTT.

Copper-based nanomaterials for cancer theranostics

Copper-based nanomaterials (Cu-based NMs) with favorable biocompatibility and unique properties have attracted the attention of many biomedical researchers. Cu-based NMs are one of the most widely studied materials in cancer treatment. In recent years, great progress has been made in the field of biomedicine, especially in the treatment and diagnosis of tumors. This review begins with the classification of Cu-based NMs and the recent synthetic strategies of Cu-based NMs. Then, according to the abundant and special properties of Cu-based NMs, their application in biomedicine is summarized in detail. For biomedical imaging, such as photoacoustic imaging, positron emission tomography imaging, and multimodal imaging based on Cu-based NMs are summarized, as well as strategies to improve the diagnostic effectiveness. Moreover, a series of unique structures and functions as well as the underlying property activity relationship of Cu-based NMs were shown to highlight their promising therapeutic performance. Cu-based NMs have been widely used in monotherapies, such as photothermal therapy (PTT) and chemodynamic therapy (CDT). Moreover, the sophisticated design in composition, structure, and surface fabrication of Cu-based NMs can endow these NMs with more modalities in cancer diagnosis and therapy. To further improve the efficiency of cancer treatment, combined therapy based on Cu-based NMs was introduced in detail. Finally, the challenges, critical factors, and future prospects for the clinical translation of Cu-based NMs as multifunctional theranostic agents were also considered and discussed. The aim of this review is to provide a better understanding and key consideration for the rational design of this increasingly important new paradigm of Cu-based NMs as theranostic agents. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Diagnostic Tools > In Vivo Nanodiagnostics and Imaging.

Atomically Precise Water-Soluble Graphene Quantum Dot for Cancer Sonodynamic Therapy

Although water-soluble graphene quantum dots (GQDs) have shown various promising bio-applications due to their intriguing optical and chemical properties, the large heterogeneity in compositions, sizes, and shapes of these GQDs hampers the better understanding of their structure-properties correlation and further uses in terms of large-scale manufacturing practices and safety concerns. It is shown here that a water-soluble atomically-precise GQD (WAGQD-C96 ) is synthesized and exhibits a deep-red emission and excellent sonodynamic sensitization. By decorating sterically hindered water-soluble functional groups, WAGQD-C96 can be monodispersed in water without further aggregation. The deep-red emission of WAGQD-C96 facilitates the tracking of its bio-process, showing a good cell-uptake and long-time retention in tumor tissue. Compared to traditional molecular sonosensitizers, WAGQD-C96 generates superior reactive oxygen species and demonstrates excellent tumor inhibition potency as an anti-cancer sonosensitizer in in vivo studies. A good biosafety of WAGQD-C96 is validated in both in vitro and in vivo assays.

A Two-In-One Nanoprodrug for Photoacoustic Imaging-Guided Enhanced Sonodynamic Therapy

Sonodynamic therapy (SDT) is garnering considerable attention in cancer treatment due to its non-invasive nature and the potential of spatiotemporal control. However, the high level of glutathione (GSH) in cancer cells can alleviate the SDT-mediated ROS-damages, resulting in a reduced SDT effect. Here, a two-in-one nano-prodrug for photoacoustic imaging-guided enhanced SDT against skin cancers is synthesized. A dual-prodrug molecule (DOA) of sulfide dioxide (SO₂ ) and 5-aminolevulinic acid (ALA) is first synthesized and then co-assembled with methoxyl poly(ethylene glycol)-b-poly(l-lysine) (mPEG-b-PLL) to generate the two-in-one prodrug nanoparticles (P-DOA NPs). The P-DOA NPs simultaneously released ALA and SO₂ in response to the overexpressed GSH in tumor cells. The released ALA is metabolically converted into protoporphyrin IX (PpIX) in tumor cells for SDT and photoacoustic imaging. Meanwhile, the released SO₂ , together with the consumption of GSH based on the reaction of DOA in P-DOA NPs with intracellular GSH, can significantly increase the intracellular ROS content, leading to enhanced SDT. As a result, the P-DOA NPs significantly inhibited the growth of melanoma and squamous cell carcinoma xenografts in mouse models under the guidance of real-time photoacoustic imaging. Therefore, this novel two-in-one nano-prodrug is promising for effective SDT against skin cancers.

Ultrasound-triggered reactive oxygen species effector nanoamplifier for enhanced combination therapy of mutant p53 tumors

Reactive oxygen species (ROS) damage is a crucial method with which to inhibit tumor cell proliferation; however, tumor cells can reduce ROS damage by modulating multiple repair mechanisms, thus, reducing the efficacy of ROS damage in tumor therapy. In this study, we built an ultrasound-triggered ROS damage nanoamplifier using a synergistic strategy consisting of ROS damage and decreased tumor self-protection capability to enhance the treatment efficacy of mutant p53 tumors. A ROS damage nanoamplifier (PT@PTGA) was fabricated using amphiphilic polyglutamic acid (PTGA) to load with a sonosensitizer (protoporphyrin IX, PpIX) and an MTH1 inhibitor (TH287). Under ultrasonic excitation, PpIX catalyzes oxygen to produce singlet oxygen and release TH287 to inhibit MTH1 activity, thereby causing the accumulation of 8-oxo-dGTP, which enhances DNA damage and further induces cell apoptosis. In addition, TH287 allies with ROS to eliminate the mutated p53 protein in tumor cells, thus reducing the self-protective capacity of tumor cells. As a result, the "internal and external" aspects were combined to enhance sensitization for mutant p53 tumor therapy. The construction of a ROS nanoamplifier not only provides an effective strategy for the treatment of mutant p53 tumors but also supplies an integrated platform for tumor diagnosis and therapy.

Glucose Metabolism Intervention-Facilitated Nanomedicine Therapy

Ordinarily, cancer cells possess features of abnormally increased nutrient intake and metabolic pathways. The disorder of glucose metabolism is the most important among them. Therefore, starvation therapy targeting glucose metabolism specifically, which results in metabolic disorders, restricted synthesis, and inhibition of tumor growth, has been developed for cancer therapy. However, issues such as inadequate targeting effectiveness and drug tolerance impede their clinical transformation. In recent years, nanomaterial-assisted starvation treatment has made significant progress in addressing these challenges, whether as a monotherapy or in combination with other medications. Herein, representative researches on the construction of nanosystems conducting starvation therapy are introduced. Elaborate designs and interactions between different treatment mechanisms are meticulously mentioned. Not only are traditional treatments based on glucose oxidase involved, but also newly sprung small molecule agents targeting glucose metabolism. The obstacles and potential for advancing these anticancer therapies were also highlighted in this review.

Nanosensitizers for sonodynamic therapy for glioblastoma multiforme: current progress and future perspectives

Glioblastoma multiforme (GBM) is the most common primary malignant brain tumor, and it is associated with poor prognosis. Its characteristics of being highly invasive and undergoing heterogeneous genetic mutation, as well as the presence of the blood-brain barrier (BBB), have reduced the efficacy of GBM treatment. The emergence of a novel therapeutic method, namely, sonodynamic therapy (SDT), provides a promising strategy for eradicating tumors via activated sonosensitizers coupled with low-intensity ultrasound. SDT can provide tumor killing effects for deep-seated tumors, such as brain tumors. However, conventional sonosensitizers cannot effectively reach the tumor region and kill additional tumor cells, especially brain tumor cells. Efforts should be made to develop a method to help therapeutic agents pass through the BBB and accumulate in brain tumors. With the development of novel multifunctional nanosensitizers and newly emerging combination strategies, the killing ability and selectivity of SDT have greatly improved and are accompanied with fewer side effects. In this review, we systematically summarize the findings of previous studies on SDT for GBM, with a focus on recent developments and promising directions for future research.

Tumor Microenvironment Triggered the In Situ Synthesis of an Excellent Sonosensitizer in Tumor for Sonodynamic Therapy

An ultrasound-triggered sonodynamic therapy has shown great promise for cancer therapy. However, its clinical applications are very limited because the traditional sonosensitizers tend to suffer from very poor efficiency combined with low retention in cancer cells and low tumor selectivity. Therefore, sonosensitizers with higher effectivity, higher tumor cell retention, and higher tumor cell specificity are highly required. Herein, we constructed a Ti2C(OH)X nanosheet, which was a poor sonosensitizer but had a long circulation in the blood system. However, it was very interesting to find that the tumor microenvironment could in situ turn Ti2C(OH)X nanosheet into a novel and excellent sonosensitizer with a nanofiber structure in tumors, exhibiting excellent ability to generate reactive oxygen species (ROS) under ultrasound. Moreover, the nanofiber structure made it very difficult to get out of cancer cells, highly enhancing the retention of the sonosensitizer in the tumor, thereby enabling it to effectively and selectively kill cancer cells in vivo. Our findings demonstrate that the strategy of the tumor microenvironment triggering the in situ synthesis of an effective sonosensitizer in tumor provided a promising means to simultaneously increase the efficiency, sonosensitizer retention in cancer cells, and cancer selectivity, thereby effectively killing cancer cells but causing little damage to healthy tissues via the sonodynamic therapy.

Biodegradable Bismuth-Based Nano-Heterojunction for Enhanced Sonodynamic Oncotherapy through Charge Separation Engineering

Sonodynamic therapy is a noninvasive treatment method that generates reactive oxygen species (ROS) triggered by ultrasound, to achieve oxidative damage to tumors. However, methods are required to improve the efficiency of ROS generation and achieve continuous oxidative damage. A ternary heterojunction sonosensitizer composed of Bi@BiO_{2- x} @Bi₂ S₃ -PEG (BOS) to achieve thermal injury-assisted continuous sonodynamic therapy for tumors is prepared. The oxygen vacancy in BOS can capture hot electrons and promotes the separation of hot carriers on the bismuth surface. The local electric field induced by localized surface plasmon resonance also contributes to the rapid transfer of electrons. Therefore, BOS not only possesses the functions of each component but also exhibits higher catalytic activity to generate ROS. Meanwhile, BOS continuously consumes glutathione, which is conducive to its biodegradation and achieves continuous oxidative stress injury. In addition, the photothermal conversion of BOS under near-infrared irradiation helps to achieve thermal tumor damage and further relieves tumor hypoxia, thus amplifying the sonodynamic therapeutic efficacy. This process not only provides a strategy for thermal damage to amplify the efficacy of sonodynamic therapy, but also expands the application of bismuth-based heterojunction nanomaterials as sonosensitizers in sonodynamic therapy.

Ultrathin-FeOOH-Coated MnO2 Sonosensitizers with Boosted Reactive Oxygen Species Yield and Remodeled Tumor Microenvironment for Efficient Cancer Therapy

Sonodynamic therapy (SDT) typically suffers from compromised anticancer efficacy owing to the low reactive oxygen species (ROS) yield and complicated tumor microenvironment (TME) which can consume ROS and support the occurrence and development of tumors. Herein, ultrathin-FeOOH-coated MnO2 nanospheres (denoted as MO@FHO) as sonosensitizers which can not only facilitate ultrasound (US)-triggered ROS but also tune the TME by hypoxia alleviation, H2 O2 consumption as well as glutathione (GSH) depletion are designed. The FeOOH coating will boost the production yield of singlet oxygen (1 O2 ) and hydroxyl radicals (• OH) by inhibiting the recombination of US-initiated electron-hole pairs and Fenton-like reaction, respectively. Additionally, the catalase-like and GSH peroxidase-like activities of MO@FHO nanospheres enable them to break the TME equilibrium via hypoxia alleviation and GSH depletion. The combination of high ROS yield and fundamental destruction of TME equilibrium results in satisfactory antitumor outcomes, as demonstrated by the high tumor suppression efficacy of MO@FHO on MDA-MB-231-tumor-bearing mice. No obvious toxicity is detected to normal tissues at therapeutic doses in vivo. The capability to modulate the ROS production and TME simultaneously can afford new probability for the development of advanced sonosensitizers for synergistic comprehensive cancer therapy.

Self-Assembly of Intelligent Nanoplatform for Endogenous H2S-Triggered Multimodal Cascade Therapy of Colon Cancer

The specific in situ generation and activation of therapeutic agents with high spatiotemporal precision is expected to revolutionize cancer treatment. Here, we develop an intelligent nanoplatform (termed as NP-Cu), which is constructed by assembling photosensitizer chlorin e6 (Ce6), hypoxia-responsive prodrug banoxantrone (AQ4N) with clickable dibenzocyclooctyne (DIBO) functionalized lysine (D-K), and cyclen-Cu²⁺ complex, for improving combination anticancer therapy. Cyclen-Cu²⁺ complex-induced photodynamic therapy (PDT) quenching in NP-Cu can be effectively and selectively activated by tumor-overproduced hydrogen sulfide (H₂S). More importantly, the reaction of endogenous H₂S with Cu²⁺ can generate photothermal agent copper sulfide (CuS) for photothermal therapy (PTT). Furthermore, with the activation of PTT and PDT, intracellular hypoxic stress is amplified to trigger AQ4N-associated chemodynamic therapy (CDT), leading to light-enhanced cascade therapy of PDT, PTT and CDT. Therefore, we present a simple and practical strategy for developing pathological stimuli responsive combination therapy, which has the potential of advancing precision cancer medicine.

Theranostic of orthotopic gliomas by core-shell structured nanoplatforms

Smart designed core-shell nanostructures formed by a YVO₄: Nd³⁺ nanoparticle as the core, the sonosensitizer hematoporphyrinmonomethyl ether as the carrier, and MnO₂ nanosheets as the shell demonstrate bimodal imaging and highly efficient sonodynamic therapy of orthotopic gliomas.

Magnetoelectric dissociation of Alzheimer's β-amyloid aggregates

The abnormal self-assembly of β-amyloid (Aβ) peptides and their deposition in the brain is a major pathological feature of Alzheimer's disease (AD), the most prevalent chronic neurodegenerative disease affecting nearly 50 million people worldwide. Here, we report a newly discovered function of magnetoelectric nanomaterials for the dissociation of highly stable Aβ aggregates under low-frequency magnetic field. We synthesized magnetoelectric BiFeO₃-coated CoFe₂O₄ (BCFO) nanoparticles, which emit excited charge carriers in response to low-frequency magnetic field without generating heat. We demonstrated that the magnetoelectric coupling effect of BCFO nanoparticles successfully dissociates Aβ aggregates via water and dissolved oxygen molecules. Our cytotoxicity evaluation confirmed the alleviating effect of magnetoelectrically excited BCFO nanoparticles on Aβ-associated toxicity. We found high efficacy of BCFO nanoparticles for the clearance of microsized Aβ plaques in ex vivo brain tissues of an AD mouse model. This study shows the potential of magnetoelectric materials for future AD treatment using magnetic field.

Two-Dimensional Nanomaterial-based catalytic Medicine: Theories, advanced catalyst and system design

Two-dimensional nanomaterial-based catalytic medicines that associate the superiorities of novel catalytic mechanisms with nanotechnology have emerged as absorbing therapeutic strategies for cancer therapy. Catalytic medicines featuring high efficiency and selectivity have been widely used as effective anticancer strategies without applying traditional nonselective and highly toxic chemodrugs. Moreover, two-dimensional nanomaterials are characterized by distinctive physicochemical properties, such as a sizeable bandgap, good conductivity, fast electron transfer and photoelectrochemical activity. The introduction of two-dimensional nanomaterials into catalytic medicine provides a more effective, controllable, and precise antitumor strategy. In this review, different types of two-dimensional nanomaterial-based catalytic nanomedicines are generalized, and their catalytic theories, advanced catalytic pathways and catalytic nanosystem design are also discussed in detail. Notably, future challenges and obstacles in the design and further clinical transformation of two-dimensional nanomaterial-based catalytic nanomedicine are prospected.

Biomimetic Nanomedicine-Triggered in Situ Vaccination for Innate and Adaptive Immunity Activations for Bacterial Osteomyelitis Treatment

The development of bacterial vaccines for inducing an immunoresponse against infectious diseases such as osteomyelitis is of great significance and importance. However, the responsiveness of bacterial immunotherapy remains far from being satisfactory, largely due to the erratic antigen epitopes of bacteria. Herein, we report an in situ vaccination strategy for the immunotherapy of bacterial infection based on an osteomyelitis model using a biomimetic nanomedicine named as HMMP, which was constructed by engineering PpIX-encapsulated hollow MnO_x with a hybrid membrane exfoliated from both macrophage and tumor cell lines. The as-established HMMP features a burst bacterial antigen release as the in situ vaccine by the augmented sonodynamic treatment and the resultant priming of antigen-presenting cells for the following activations of both cellular and humoral adaptive immunities against bacterial infections. This treatment regimen not only triggers initial bacterial regression in the established osteomyelitis model but also simultaneously generates robust systemic antibacterial immunity against poorly immunogenic secondary osteomyelitis in the contralateral knee and additionally confers long-lasting bacteria-specific immune memory responses to prevent infection relapse. Thus, our study provides a proof of concept of in situ vaccination for the activation of both innate and adaptive antibacterial immune responses, providing an individual-independent bacterial immunotherapy.

2D Molybdenum Sulfide-Based Materials for Photo-Excited Antibacterial Application

Bacterial infections have seriously threatened human health and the abuse of natural or artificial antibiotics leads to bacterial resistance, so development of a new generation of antibacterial agents and treatment methods is urgent. 2D molybdenum sulfide (MoS₂ ) has good biocompatibility, high specific surface area to facilitate surface modification and drug loading, adjustable energy bandgap, and high near-infrared photothermal conversion efficiency (PCE), so it is often used for antibacterial application through its photothermal or photodynamic effects. This review comprehensively summarizes and discusses the fabrication processes, structural characteristics, antibacterial performance, and the corresponding mechanisms of MoS₂ -based materials as well as their representative antibacterial applications. In addition, the outlooks on the remaining challenges that should be addressed in the field of MoS₂ are also proposed.

Open-Shell Nanosensitizers for Glutathione Responsive Cancer Sonodynamic Therapy

Deleterious effects to normal tissues and short biological half-life of sonosensitizers limit the applications of sonodynamic therapy (SDT). Herein, a new sonosensitizer (Cu(II)NS) is synthesized that consists of porphyrins, chelated Cu2+ , and poly(ethylene glycol) (PEG) to overcome the challenges of SDT. As Cu2+ contains 27 electrons, Cu(II)NS has an unpaired electron (open shell), resulting in a doublet ground state and little sonosensitivity. Overexpressed glutathione in the tumor can reduce Cu2+ to generate Cu(I)NS, leading to a singlet ground state and recuperative sonosensitivity. Additionally, PEG endows Cu(II)NS with increased blood biological half-life and enhanced tumor accumulation, further increasing the effect of SDT. Through regulating the valence state of Cu, cancer SDT with enhanced therapeutic index is achieved.

Hollow Mesoporous Manganese Oxides: Application in Cancer Diagnosis and Therapy

The precision, minimal invasiveness, and integration of diagnosis and treatment are critical factors for tumor treatment at the present. Although nanomedicine has shown the potential in tumor precision treatment, nanocarriers with high efficiency, excellent targeting, controlled release, and good biocompatibility still need to be further explored. Hollow mesoporous manganese oxides nanomaterials (HM-MONs), as an efficient drug delivery carrier, have attracted substantial attention in applications of tumor diagnosis and therapy due to their unique properties, such as tumor microenvironment stimuli-responsiveness, prominent catalytic activity, excellent biodegradation, and outstanding magnetic resonance imaging ability. The HM-MONs can not only enhance the therapeutic efficiency but also realize multimodal diagnosis of tumors. Consequently, it is necessary to introduce applications based on HM-MONs in cancer diagnosis and therapy. In this review, the representative progress of HM-MONs in synthesis is discussed. Then, several promising applications in drug delivery, bio-imaging, and bio-detection are highlighted. Finally, the challenges and perspectives of the anticancer applications are summarized, which is expected to provide meaningful guidance on further research.

Ultrasound-activated nanomaterials for sonodynamic cancer theranostics

Despite intensive efforts to develop diagnostic and therapeutic tools, the successful treatment of cancer is still hampered by the obscure boundary between cancerous cells and normal cells, recurrence of the cancer, and the development of drug resistance during chemotherapy. In recent years, sonodynamic therapy (SDT), employing therapeutic ultrasound with sonosensitizers, has attracted attention as a potentially promising approach for cancer therapy. This review describes the current understanding of the mechanisms and the preclinical and clinical efficacy of SDT-based applications in tumors, providing an insight into the therapeutic potential offered by SDT. The limitations and future directions of this emerging treatment are also discussed.

Biomimetic Activator of Sonodynamic Ferroptosis Amplifies Inherent Peroxidation for Improving the Treatment of Breast Cancer

Ferroptosis is a type of nonapoptotic cell death and is gradually emerging as an important anticancer treatment. However, its therapeutic efficacy is impaired by low intracellular levels of reactive oxygen species (ROS) and long-chain polyunsaturated fatty acids, significantly limiting its therapeutic potential. Herein, a multimodal strategy to improve ferroptosis is presented, in which a state-of-art engineered erythrocyte, termed as sonodynamic amplified ferroptosis erythrocyte (SAFE), is developed for simultaneously activating ferroptosis and oxygen-riched sonodynamic therapy (SDT). SAFE is composed of internalizing RGD peptide and red blood cell membrane hybrid camouflaged nanocomplex of hemoglobin, perfluorocarbon, ferroptosis activator (dihomo-γ-linolenic acid, DGLA), and sonosensitizer verteporfin. It is identified that SAFE, under ultrasound stimulation, can not only substantially supply oxygen to overcome tumor hypoxia associated therapeutic resistance, but effectively activate ferroptosis through the coeffect of SDT triggered ROS production and DGLA mediated lipid peroxidation. In vivo studies reveal that SAFE selectively accumulates in tumor tissues and induces desirable anticancer effects under mild ultrasound stimulation. Importantly, SAFE can effectively inhibit tumor growth with minimal invasiveness, resulting in a prolonged survival period of mice. Therefore, a multimodal ferroptosis therapy driven by oxygen-riched sonodynamic peroxidation of lipids, significantly advancing synergistic cancer treatment, is presented.

Oxygen-Deficient BiOCl Combined with L-Buthionine-Sulfoximine Synergistically Suppresses Tumor Growth through Enhanced Singlet Oxygen Generation under Ultrasound Irradiation

Excess generation of reactive oxygen species (ROS) based on sensitizers under ultrasound (US) excitation can cause the death of tumor cells via oxidative damage, but sonosensitizers are largely unexplored. Herein, oxygen-deficient black BiOCl (B-BiOCl) nanoplates (NPs) are reported, with post-treatment on conventional BiOCl by simple UV excitation, showing stronger singlet oxygen (¹ O₂ ) generation than commercial TiO₂ nanoparticles and their derivatives under US irradiation. Moreover, L-buthionine-sulfoximine (BSO), a GSH biosynthesis inhibitor, is incorporated into B-BiOCl NPs. The authors find that BSO can be released owing to the degradation of B-BiOCl NPs in the presence of acid and GSH, which are overexpressed in tumors. The results show that BSO/B-BiOCl-PEG NPs have a multifunctional synergistic effect on improving ROS production. In particular, BiOCl has remarkable near-infrared light absorption after UV treatment and is good for photoacoustic imaging that can guide subsequent sonodynamic therapy. This work shows that just with a simple oxygen deficiency treatment, strong ¹ O₂ generation can be provided to a conventional material under US irradiation and, interestingly, this effect can be amplified by using a small inhibitor BSO, and this is clearly demonstrated in cell and mice experiments.

Emerging Single-Atom Catalysts/Nanozymes for Catalytic Biomedical Applications

Single-atom catalysts (SACs) are a type of atomically dispersed nanozymes with the highest atom utilization, which employ low-coordinated single atoms as the catalytically active sites. SACs not only inherit the merits of traditional nanozymes, but also hold high catalytic activity and superb catalytic selectivity, which ensure their tremendous application potential in environmental remediation, energy storage and conversion, chemical industry, nanomedicine, etc. Nevertheless, undesired aggregation effect of single atoms during preactivation and reaction processes is significantly enhanced owing to the high surface free energy of single atoms. In this case, appropriate substrates are requisite to prevent the aggregation event through the powerful interactions between the single atoms and the substrates, thereby stabilizing the high catalytic activity of the catalysts. In this review, the synthetic methods and characterization approaches of SACs are first described. Then the application cases of SACs in nanomedicine are summarized. Finally, the current challenges and future opportunities of the SACs in nanomedicine are outlined. It is hoped that this review may have implications for furthering the development of new SACs with improved biophysicochemical properties and broadened biomedical applications.

Recent Advance of Nanomaterial-Mediated Tumor Therapies in the Past Five Years

Cancer has posed a major threat to human life and health with a rapidly increasing number of patients. The complexity and refractory of tumors have brought great challenges to tumor treatment. In recent years, nanomaterials and nanotechnology have attracted more attention and greatly improved the efficiency of tumor therapies and significantly prolonged the survival period, whether for traditional tumor treatment methods such as radiotherapy, or emerging methods, such as phototherapy and immunotherapy, sonodynamic therapy, chemodynamic therapy and RNA interference therapeutics. Various monotherapies have obtained positive results, while combination therapies are further proposed to prevent incomplete eradication and recurrence of tumors, strengthen tumor killing efficacy with minimal side effects. In view of the complementary promotion effects between different therapies, it is vital to utilize nanomaterials as the link between monotherapies to achieve synergistic performance. Further development of nanomaterials with efficient tumor-killing effect and better biosafety is more in line with the needs of clinical treatment. In a word, the development of nanomaterials provides a promising way for tumor treatment, and here we will review the emerging nanomaterials towards radiotherapy, phototherapy and immunotherapy, and summarized the developed nanocarriers applied for the tumor combination therapies in the past 5 years, besides, the advances of some other novel therapies such as sonodynamic therapy, chemodynamic therapy, and RNA interference therapeutics have also been mentioned.

Tumor microenvironment-responsive fenton nanocatalysts for intensified anticancer treatment

Chemodynamic therapy (CDT) based on Fenton or Fenton-like reactions is an emerging cancer treatment that can both effectively fight cancer and reduce side effects on normal cells and tissues, and it has made important progress in cancer treatment. The catalytic efficiency of Fenton nanocatalysts(F-NCs) directly determines the anticancer effect of CDT. To learn more about this new type of therapy, this review summarizes the recent development of F-NCs that are responsive to tumor microenvironment (TME), and detailedly introduces their material design and action mechanism. Based on the deficiencies of them, some effective strategies to significantly improve the anticancer efficacy of F-NCs are highlighted, which mainly includes increasing the temperature and hydrogen peroxide concentration, reducing the pH, glutathione (GSH) content, and the dependence of F-NCs on acidic environment in the TME. It also discusses the differences between the effect of multi-mode therapy with external energy (light and ultrasound) and the single-mode therapy of CDT. Finally, the challenges encountered in the treatment process, the future development direction of F-NCs, and some suggestions are analyzed to promote CDT to enter the clinical stage in the near future.

Guiding Transition Metal-Doped Hollow Cerium Tandem Nanozymes with Elaborately Regulated Multi-Enzymatic Activities for Intensive Chemodynamic Therapy

Clinical applications of nanozyme-initiated chemodynamic therapy (NCDT) have been severely limited by the poor catalytic efficiency of nanozymes, insufficient endogenous hydrogen peroxide (H₂ O₂ ) content, and its off-target consumption. Herein, the authors developed a hollow mesoporous Mn/Zr-co-doped CeO₂ tandem nanozyme (PHMZCO-AT) with regulated multi-enzymatic activities, that is, the enhancement of superoxide dismutase (SOD)-like and peroxidase (POD)-like activities and inhibition of catalase (CAT)-like activity. PHMZCO-AT as a H₂ O₂ homeostasis disruptor promotes H₂ O₂ evolution and restrains off-target elimination of H₂ O₂ to achieve intensive NCDT. PHMZCO-AT with SOD-like activity catalyzes endogenous superoxide anion (O₂ ^•- ) into H₂ O₂ in the tumor region. The suppression of CAT activity and depletion of glutathione by PHMZCO-AT largely weaken the off-target decomposition of H₂ O₂ to H₂ O. Elevated H₂ O₂ is then catalyzed by the downstream POD-like activity of PHMZCO-AT to generate toxic hydroxyl radicals, further inducing tumor apoptosis and death. T₁ -weighted magnetic resonance imaging and X-ray computed tomography imaging are also achieved using PHMZCO-AT due to the existence of paramagnetic Mn²⁺ and the high X-ray attenuation ability of elemental Zr, permitting in vivo tracking of the therapeutic process. This work presents a typical paradigm to achieve intensive NCDT efficacy by regulating multi-enzymatic activities of nanozymes to perturb the H₂ O₂ homeostasis.

Platinum Crosslinked Carbon Dot@TiO2-x p-n Junctions for Relapse-Free Sonodynamic Tumor Eradication via High-Yield ROS and GSH Depletion

Sonodynamic therapy as a promising noninvasive modality is being developed for tumor therapy, but there is a lack of next-generation sonosensitizers that can generate full ROS at high yields and simultaneously deplete elevated levels of glutathione (GSH) in tumor cells. Semiconductor p-n junctions are engineered as high-efficacy sonosensitizers for sonodynamic tumor eradication using pyridine N-doped carbon dots (N-CDs) as a p-type semiconductor and oxygen-deficient TiO_2-x nanosheets as a n-type semiconductor. The rate constants of ¹ O₂ and •OH generation by ultrasound-excited N-CD@TiO_2-x p-n junctions are 4.3 and 4.5 times higher than those of TiO₂ , respectively. A Z-scheme carrier migration mechanism in the p-n junction achieving the rapid spatial separation of the ultrasound-generated electron-hole pairs for enhanced full ROS production is proposed. GSH-cleavable, Pt-crosslinked, N-doped CD fluorescent probes to detect the presence of intracellular GSH are also constructed. A GSH-responsive, p-n junction platform (Pt/N-CD@TiO_2-x ) with integrated GSH detection, GSH depletion, and enhanced sonodynamic performance is then assembled. Malignant tumors are completely eradicated without relapse via intravenous administration of low-dose Pt/N-CD@TiO_2-x under ultrasound irradiation. This work substantiates the great potential of biocompatible, GSH-responsive p-n junctions as next-generation sonosensitizers via p-n junction-enhanced ROS generation and metal ion oxidation of intracellular GSH.

Aggregation-Enhanced Sonodynamic Activity of Phthalocyanine-Artesunate Conjugates

The clinical prospect of sonodynamic therapy (SDT) has not been fully realized due to the scarcity of efficient sonosensitizers. Herein, we designed phthalocyanine-artesunate conjugates (e.g. ZnPcT4 A), which could generate up to ca. 10-fold more reactive oxygen species (ROS) than the known sonosensitizer protoporphyrin IX. Meanwhile, an interesting and significant finding of aggregation-enhanced sonodynamic activity (AESA) was observed for the first time. ZnPcT4 A showed about 60-fold higher sonodynamic ROS generation in the aggregated form than in the disaggregated form in aqueous solutions. That could be attributed to the boosted ultrasonic cavitation of nanostructures. The level of the AESA effect depended on the aggregation ability of sonosensitizer molecules and the particle size of their aggregates. Moreover, biological studies demonstrated that ZnPcT4 A had high anticancer activities and biosafety. This study thus opens up a new avenue the development of efficient organic sonosensitizers.

Ultrasound-Enhanced Reactive Oxygen Species Responsive Charge-Reversal Polymeric Nanocarriers for Efficient Pancreatic Cancer Gene Delivery

Inefficient intracellular gene release and transfection limit nonviral gene delivery applications in cancer therapy. Reactive oxygen species (ROS) responsive nonviral gene delivery is the most widely explored strategy for such applications, yet the development of fast and safe ROS responsive nanocarriers proves to be a challenge because of the intracellular chemical equilibrium of high ROS and glutathione levels. Here, we report an ultrasound-enhanced ROS responsive charge-reversal polymeric nanocarrier (BTIL) for fast and efficient pancreatic cancer gene delivery. The BTIL is composed of B-PDEAEA/DNA polyplex-based cores and IR780-loaded liposome coatings. The IR780 is able to produce an excess of ROS under low intensity ultrasound irradiation, thus disequilibrating the chemical equilibrium of ROS and glutathione, and promoting the ROS-responsive positive-to-negative charge-reversal of the B-PDEAEA polymer. This charge conversion results in fast polyplex dissociation and intracellular gene release, inducing efficient gene transfection and cancer cell apoptosis. Moreover, following the intravenous administration, BTIL maintains a stable and long circulation in the bloodstream, achieves orthotopic pancreatic ductal adenocarcinoma distribution, and exhibits potent antitumor activity with negligible side effects. Our results reveal the proposed strategy to be both promising and universal for the development of fast and safe ROS responsive nonviral gene delivery in cancer therapy.

An Urchin-Shaped Copper-Based Metalloporphyrin Nanosystem as a Sonosensitizer for Sonodynamic Therapy

Sonodynamic therapy (SDT), as a novel cancer therapy strategy, might be a promising approach due to the depth-penetration property in tissue. Sonosensitizers are the key element for efficient SDT. However, the development of sonosensitizers with strong sonosensitization efficacy is still a significant challenge. Herein, an urchin-shaped copper-based metalloporphyrin liposome nanosystem (FA-L-CuPP) is constructed and identified as an excellent sonosensitizer. Under ultrasound (US) irradiation, FA-L-CuPP can be highly excited to generate several reactive oxygen species (ROS), such as singlet oxygen (1O2) and free radicals (⋅OH). The molecular orbital distribution calculations reveal that a strong intramolecular charge transfer might occur in the CuPP complex under US irradiation, which could afford enough energy to the surrounding O2 and H2O to concert 1O2, O2- and ⋅OH. Working as "ammunitions", the largely produced ROS can kill 4T1 tumor cells, effectively inhibiting tumor growth. This work provides an urchin-shaped nanosonosensitizer based on a copper complex, which might provide an idea to design a novel sonosensitizer for noninvasive and precise SDT antitumor applications.

RNA-Seq Explores the Mechanism of Oxygen-Boosted Sonodynamic Therapy Based on All-in-One Nanobubbles to Enhance Ferroptosis for the Treatment of HCC

BACKGROUND

The combination of sonodynamic therapy and oxygenation strategy is widely used in cancer treatment. However, due to the complexity, heterogeneity and irreversible hypoxic environment produced by hepatocellular carcinoma (HCC) tissues, oxygen-enhancing sonodynamic therapy (SDT) has failed to achieve the desired results. With the emergence of ferroptosis with reactive oxygen species (ROS) cytotoxicity, this novel cell death method has attracted widespread attention.

METHODS

In this study, nanobubbles (NBs) were connected with the sonosensitizer Indocyanine green (ICG) to construct a 2-in-1 nanoplatform loaded with RAS-selective lethal (RSL3, ferroptosis promoter) (RSL3@O2-ICG NBs), combined with oxygen-enhanced SDT and potent ferroptosis. In addition, nanobubbles (NBs) combined with low-frequency ultrasound (LFUS) are called ultrasound-targeted nanobubble destruction (UTND) to ensure specific drug release and improve safety.

RESULTS

MDA/GSH and other related experimental results show that RSL3@O2-ICG NBs can enhance SDT and ferroptosis. Through RNA sequencing (RNA-seq), the differential expression of LncRNA and mRNA before and after synergistic treatment was identified, and then GO and KEGG pathways were used to enrich and analyze target genes and pathways related ferroptosis sensitivity. We found that they were significantly enriched in the ferroptosis-related pathway MAPK cascade and cell proliferation. Then, we searched for the expression of differentially expressed genes in the TCGA Hepatocellular carcinoma cohort. At the same time, we evaluated the proportion of immune cell infiltration and the identification of co-expression network modules and related prognostic analysis. We found that it was significantly related to the tumor microenvironment of hepatocellular carcinoma. The prognostic risk genes "SLC37A2" and "ITGB7" may represent new hepatocellular carcinoma ferroptosis-inducing markers and have guiding significance for treating hepatocellular carcinoma.

CONCLUSION

The therapeutic effect of the in vitro synergistic treatment has been proven to be significant, revealing the prospect of 2-in-1 nanobubbles combined with SDT and ferroptosis in treating HCC.

A hydrogen peroxide economizer for on-demand oxygen production-assisted robust sonodynamic immunotherapy

The outcome of sonodynamic immunotherapy is significantly limited by tumor hypoxia. To overcome this obstacle, one common solution is to catalyze the conversion of endogenous H₂O₂ into O₂. However, the effectiveness of this strategy is limited by the insufficient concentration of H₂O₂ in the tumor microenvironment (TME). Herein, we developed a H₂O₂ economizer for on-demand O₂ supply and sonosensitizer-mediated reactive oxygen species production during ultrasound activation, thereby alleviating hypoxia-associated limitations and augmenting the efficacy of sonodynamic immunotherapy. Methods: The H₂O₂ economizer is constructed by electrostatic adsorption and π-π interactions between the Fe-doped polydiaminopyridine (Fe-PDAP) nanozyme and chlorin e6. By employing a biomimetic engineering strategy with cancer cell membranes, we addressed the premature leakage issue and increased tumor-site accumulation of nanoparticles (membrane-coated Fe-PDAP/Ce6, MFC). Results: The prepared MFC could significantly attenuate the catalytic activity of Fe-PDAP by reducing their contact with H₂O₂. Ultrasound irradiation promoted MFC dissociation and the exposure of Fe-PDAP for a more robust O₂ supply. Moreover, the combination of MFC-enhanced sonodynamic therapy with anti-programmed cell death protein-1 antibody (aPD-1) immune checkpoint blockade induced a strong antitumor response against both primary tumors and distant tumors. Conclusion: This as-prepared H₂O₂ economizer significantly alleviates tumor hypoxia via reducing H₂O₂ expenditure and that on-demand oxygen-elevated sonodynamic immunotherapy can effectively combat tumors.

Tumor-targeting biomimetic sonosensitizer-conjugated iron oxide nanocatalysts for combinational chemodynamic-sonodynamic therapy of colorectal cancer

Nanoparticle-based tumor therapy strategies have been widely developed, while the therapeutic efficacy is often limited due to poor accumulation of nanoparticles in tumor tissues and low antitumor effect of sole...

Silver Peroxide Nanoparticles for Combined Antibacterial Sonodynamic and Photothermal Therapy

Metal peroxide nanoparticles designed to elevate the oxidative stress are considered a promising nanotherapeutics in biomedical applications, including chemotherapy, photodynamic therapy, and bacterial disinfection. However, their lack of specificity towards the therapeutic target can cause toxic side effects to healthy tissues. Here, silver peroxide nanoparticles (Ag₂ O₂ NPs) capable of controlled reactive oxygen species (ROS) release are synthesized. The release of bactericidal Ag⁺ ions and ROS is strictly regulated by external stimuli of ultrasound (US) and near-infrared (NIR) light. In vitro and in vivo investigations show that the Ag₂ O₂ NPs present enhanced antibacterial and antibiofilm capabilities with a killing efficiency >99.9999% in 10 min, significantly accelerate multi-drug resistant Staphylococcus aureus infected skin wound closure with excellent cytocompatibility and hemocompatibility. This work not only provides the first paradigm for fabricating silver peroxide nanoparticle but also introduces a highly efficient noninvasive and safe therapeutic modality for combating bacterial infectious diseases.

A Mitochondria-Localized Iridium(III)-Chlorin E6 Conjugate for Synergistic Sonodynamic and Two-Photon Photodynamic Therapy Against Melanoma

While melanoma in its early stages can be successfully treated, the prognosis strongly worsens with an increasing depth of the tumor. Capitalizing on this, there is an urgent need for...

Acidic TME-Responsive Nano-Bi2 Se3 @MnCaP as a NIR-II-Triggered Free Radical Generator for Hypoxia-Irrelevant Phototherapy with High Specificity and Immunogenicity

Here, acidic tumor microenvironment (TME)-responsive nano-Bi₂ Se₃ @MnCaP, as a near-infrared-II (NIR-II) biowindow-triggered free radical generator for hypoxia-irrelevant phototherapy, is elaborately developed by biomimetic mineralization of MnCaP onto 2, 2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride (AIPH)-loaded mesoporous nano-Bi₂ Se₃ to form Bi₂ Se₃ /AIPH@MnCaP (BAM). Surface mineral of MnCaP can be degraded under mild acidity, leading to the release of both Mn²⁺ and AIPH. The leached Mn²⁺ not only facilitates chemodynamic therapy (CDT) via hydroxyl radicals (^• OH) from Mn²⁺ -mediated Fenton-like reaction but also acts as contrast agent for magnetic resonance imaging. In another aspect, the splendid photothermal conversion capacity of BAM enables a rapid hyperthermia generation under NIR-II laser irradiation for photothermal therapy (PTT). Simultaneously, the local thermal shock can induce the disintegration of AIPH to generate alkyl radicals (^• R) for thermodynamic therapy (TDT) and accelerate Fenton-like reaction rate to augment CDT efficacy. The strong synergistic effects from cooperative CDT/PTT/TDT are applied to 4T1 tumor suppression with minimal side effects. Importantly, the combination therapy can effectively trigger immunogenetic cell death and enhance antitumor immunity for systemic tumor eradication. Collectively, this proof-of-concept study demonstrates a more efficacious and safer strategy for oxygenation-independent phototherapy, which holds a good potential for clinical translation in cancer management.