Tumor microenvironment-responsive MnSiO3-Pt@BSA-Ce6 nanoplatform for synergistic catalysis-enhanced sonodynamic and chemodynamic cancer therapy

Application of Nanomaterial-Based Sonodynamic Therapy in Tumor Therapy

Sonodynamic therapy (SDT) has attracted significant attention in recent years as it is an innovative approach to tumor treatment. It involves the utilization of sound waves or ultrasound (US) to activate acoustic sensitizers, enabling targeted drug release for precise tumor treatment. This review aims to provide a comprehensive overview of SDT, encompassing its underlying principles and therapeutic mechanisms, the applications of nanomaterials, and potential synergies with combination therapies. The review begins by introducing the fundamental principle of SDT and delving into the intricate mechanisms through which it facilitates tumor treatment. A detailed analysis is presented, outlining how SDT effectively destroys tumor cells by modulating drug release mechanisms. Subsequently, this review explores the diverse range of nanomaterials utilized in SDT applications and highlights their specific contributions to enhancing treatment outcomes. Furthermore, the potential to combine SDT with other therapeutic modalities such as photothermal therapy (PTT) and chemotherapy is discussed. These combined approaches aim to synergistically improve therapeutic efficacy while mitigating side effects. In conclusion, SDT emerges as a promising frontier in tumor treatment that offers personalized and effective treatment options with the potential to revolutionize patient care. As research progresses, SDT is poised to play a pivotal role in shaping the future landscape of oncology by providing patients with a broader spectrum of efficacious and tailored treatment options.

Metal-Phenolic Nanocloaks on Cancer Cells Potentiate STING Pathway Activation for Synergistic Cancer Immunotherapy

Due to the presence of natural neoantigens, autologous tumor cells hold great promise as personalized therapeutic vaccines. Yet autologous tumor cell vaccines require multi-step production that frequently leads to the loss of immunoreactive antigens, causing insufficient immune activation and significantly hampering their clinical applications. Herein, we introduce a novel whole-cell cancer vaccine by cloaking cancer cells with lipopolysaccharide-decorated manganese(II)-phenolic networks (MnTA nanocloaks) to evoke tumor-specific immune response for highly efficacious synergistic cancer immunotherapy. The natural polyphenols coordinate with Mn2+ and immediately adhere to the surface of individual cancer cells, thereby forming a nanocloak and encapsulating tumor neoantigens. Subsequent decoration with lipopolysaccharide induces internalization by dendritic cells, where Mn2+ ions are released in the cytosol, further facilitating the activation of the stimulator of the interferon genes (STING) pathway. Highly effective tumor suppression was observed by combining the nanocloaked cancer cell treatment with anti-programmed cell death ligand 1 (anti-PD-L1) antibodies-mediated immune checkpoint blockade therapy. Our work demonstrates a universal yet simple strategy to engineer a cell-based nanobiohybrid system for enhanced cancer immunotherapy.

Optimized silicate nanozymes with atomically incorporated iron and manganese for intratumoral coordination-enhanced once-for-all catalytic therapy

Although plant-derived cancer therapeutic products possess great promise in clinical translations, they still suffer from quick degradation and low targeting rates. Herein, based on the oxygen vacancy (OV)-immobilization strategy, an OV-enriched biodegradable silicate nanoplatform with atomically dispersed Fe/Mn active species and polyethylene glycol modification was innovated for loading gallic acid (GA) (noted as FMMPG) for intratumoral coordination-enhanced multicatalytic cancer therapy. The OV-enriched FMMPG nanozymes with a narrow band gap (1.74 eV) can be excited by a 650 nm laser to generate reactive oxygen species. Benefiting from the Mn-O bond in response to the tumor microenvironment (TME), the silicate skeleton in FMMPG collapses and completely degrades after 24 h. The degraded metal M (M = Fe, Mn) ions and released GA can in situ produce a stable M-GA nanocomplex at tumor sites. Importantly, the formed M-GA with strong reductive ability can transform H2O2 into the fatal hydroxyl radical, causing serious oxidative damage to the tumor. The released Fe3+ and Mn2+ can serve as enhanced contrast agents for magnetic resonance imaging, which can track the chemodynamic and photodynamic therapy processes. The work offers a reasonable strategy for a TME-responsive degradation and intratumoral coordination-enhanced multicatalytic therapy founded on bimetallic silicate nanozymes to achieve desirable tumor theranostic outcomes.

All-in-one HN@Cu-MOF nanoparticles with enhanced reactive oxygen species generation and GSH depletion for effective tumor treatment

Non-invasive cancer therapies, especially those based on reactive oxygen species, including photodynamic therapy (PDT), have gained much interest. As emerging photodynamic nanocarriers, metal-organic frameworks (MOFs) based on porphyrin can release reactive oxygen species (ROS) to destroy cancer cells. However, due to the inefficient production of ROS by photosensitizers and the over-expression of glutathione (GSH) in the tumor microenvironment (TME), their therapeutic effect is not satisfactory. Therefore, herein, we developed a multi-functional nanoparticle, HN@Cu-MOF, to enhance the efficacy of PDT. We combined chemical dynamic therapy (CDT) and nitric oxide (NO) therapy by initiating sensitization to PDT and cell apoptosis in the treatment of tumors. The Cu2+-doped MOF reacted with GSH to form Cu+, exhibiting a strong CDT ability to generate hydroxyl radicals (˙OH). The Cu-MOF was coated with HN, which is hyaluronic acid (HA) modified by a nitric oxide donor. HN can target tumor cells over-expressing the CD44 receptor and consume GSH in the cells to release NO. Both cell experiments and in vivo experiments showed an excellent tumor inhibitory effect upon the treatment. Overall, the HN@Cu-MOF nanoparticle-integrated NO gas therapy and CDT with PDT led to a significant enhancement in GSH consumption and a remarkable elevation in ROS production.

Platinum nanoparticle-anchored metal-organic complex nanospheres by a coordination-crystallization approach for enhanced sonodynamic therapy of tumors

The combination of noble metal nanoparticles with metal-organic complexes has attracted great attention for exploring new properties in biomedical application areas. So far, the preparation of noble metal nanoparticle-loaded metal-organic complexes often requires complex processes. Here, a simple coordination-crystallization approach was developed to prepare platinum nanoparticle-anchored metal-organic complexes (Pt-MOCs) by directly mixing disulfiram (DSF), chloroplatinic acid, and a reducing agent. The DSF and Pt ions first coordinate forming metal-organic complex nanospheres and then the Pt nanoparticles crystallized on the surface taking advantage of the coordination rate of the metal ions and organic ligand being greater than the reduction rate of the metal ions. The Pt-MOCs possess uniform and adjustable diameter (240-536 nm), and their surface potentials can also be modulated easily from -22 to +14 mV by adjusting the ratio of DSF and chloroplatinic acid. Phantom experiments show that the Pt-MOC nanospheres significantly improve the efficiency of singlet oxygen production after exposure to ultrasound irradiation. In vitro experiments show that the Pt-MOCs effectively produce reactive oxygen species and exhibit superior cytotoxicity for tumor cells under ultrasound irradiation compared to metal-organic complexes (MOCs) or Pt nanoparticles. Taken together, this work reports a coordination-crystallization approach to synthesize Pt-MOCs, which show excellent sonodynamic therapy for tumors.

Mn(II)-hemoporfin-based metal-organic frameworks as a theranostic nanoplatform for MRI-guided sonodynamic therapy

Imaging-guided therapy holds great potential for enhancing therapeutic performance in a personalized way. However, it is still challenging to develop appropriate multifunctional materials to overcome the limitations of current all-in-one theranostic agents. In this study, we developed a one-for-all theranostic nanoplatform called Mn(II)-hemoporfin MOFs, designed specifically for MRI-guided sonodynamic tumor therapy. The formation of MOF structures not only improves imaging but also enhances therapeutic effects through collective actions. Furthermore, by modifying polyethylene glycol (PEG), Mn(II)-hemoporfin-PEG was able to enhance permeability and retention effects, ensuring long circulation in the blood and accumulation in the tumor. MRI enhancement provided by Mn(II)-hemoporfin-PEG remained localized at the tumor site, with Mn(II)-hemoporfin-PEG demonstrating 88.6% efficacy in sonodynamic therapy testing in vivo. Mn(II)-hemoporfin-PEG exhibits excellent longitudinal relaxation, MRI effects, and sonodynamic performance, making it a promising alternative for clinical cancer treatment.

Biomineralized RuO2 Nanozyme with Multi-Enzyme Activity for Ultrasound-Triggered Peroxynitrite-Boosted Ferroptosis

Ferroptosis, as a non-apoptotic cell death pathway, has attracted increasing attention for cancer therapy. However, the clinical application of ferroptosis-participated modalities is severely limited by the low efficiency owing to the intrinsic intracellular regulation pathways. Herein, chlorin e6 (Ce6) and N-acetyl-l-cysteine-conjugated bovine serum albumin-ruthenium dioxide is elaborately designed and constructed for ultrasound-triggered peroxynitrite-mediated ferroptosis. Upon ultrasound stimulation, the sonosensitizers of Ce6 and RuO2 exhibit highly efficient singlet oxygen (1 O2 ) generation capacity, which is sequentially amplified by superoxide dismutase and catalase-mimicking activity of RuO2 with hypoxia relief. Meanwhile, the S-nitrosothiol group in BCNR breaks off to release nitric oxide (NO) on-demand, which then reacts with 1 O2 forming highly cytotoxic peroxynitrite (ONOO- ) spontaneously. Importantly, BCNR nanozyme with glutathione peroxidase-mimicking activity can consume glutathione (GSH), along with the generated ONOO- downregulates glutathione reductase, avoiding GSH regeneration. The two-parallel approach ensures complete depletion of GSH within the tumor, resulting in the boosted ferroptosis sensitization of cancer cells. Thus, this work presents a superior paradigm for designing peroxynitrite-boosted ferroptosis sensitization cancer therapeutic.

Prodrug-loaded semiconducting polymer hydrogels for deep-tissue sono-immunotherapy of orthotopic glioblastoma

Although immunotherapy has achieved great success in the treatment of a variety of tumors, its efficacy for glioblastoma (GBM) is still limited. Both the immunosuppressive tumor microenvironment (TME) and poor penetration of immunotherapeutic agents into tumors contributed to the poor anti-glioma immunity. Herein, we develop an injectable prodrug-loaded hydrogel delivery system with sono-activatable properties for sonodynamic therapy (SDT)-triggered immunomodulation for GBM treatment. The prodrug alginate hydrogels (APN), which contain semiconducting polymer nanoparticles (SPNs) and the NLG919 prodrug linked by singlet oxygen (1O2)-cleavable linkers, are in situ formed via coordination of alginate solution with Ca2+ in the TME. SPNs serve as sonosensitizers to produce 1O2 upon ultrasound (US) irradiation for SDT. The generated 1O2 not only induce immunogenic cell death, but also break 1O2-cleavable linkers to precisely activate the NLG919 prodrug. Antitumor immunity is significantly amplified due to the reversal of immunosuppression mediated by indolamine 2,3-dioxygenase-dependent tryptophan metabolism. This smart prodrug hydrogel platform potently inhibits tumor growth in orthotopic glioma-bearing mice. Collectively, this work provides a sono-activatable hydrogel platform for precise sono-immunotherapy against GBM.

Bioparameter-directed nanoformulations as MRI CAs enable the specific visualization of hypoxic tumour

A malignant tumour has hypoxic cells of varying degrees. The more severe the hypoxic degree, the more difficult the prognosis of the tumour and the higher the recurrence rate. Therefore, tumour hypoxia imaging is crucial. Magnetic resonance imaging (MRI) shows its strength in high resolution, depth of penetration and noninvasiveness. However, it needs more excellent contrast agents (CAs) to combat the complex tumour microenvironment (TME) and increased targeting of tumours to enhance clinical safety. Many research studies have focused on developing hypoxia-responsive MRI CAs that take advantage of the unique characteristics of hypoxic tumours. The low oxygen pressure, acidic TME, and up-regulated redox molecule levels found in hypoxic tumours serve as biological stimuli for nanoformulations that can accurately image the hypoxic region. This review highlights the importance of developing bioparameter-directed nanoformulations as MRI CAs for accurate tumour diagnosis. The design strategies and mechanisms of tumour-hypoxia imaging with nanoformulations are exemplified, with a focus on pH-responsiveness, redox-responsiveness, and p(O2)-responsiveness. The promising future of bioparameter-responsive nanoformulations for accurate tumour diagnosis and personalised cancer treatment is discussed.

Ultrasound Sonosensitizers for Tumor Sonodynamic Therapy and Imaging: A New Direction with Clinical Translation

With the rapid development of sonodynamic therapy (SDT), sonosensitizers have evolved from traditional treatments to comprehensive diagnostics and therapies. Sonosensitizers play a crucial role in the integration of ultrasound imaging (USI), X-ray computed tomography (CT), and magnetic resonance imaging (MRI) diagnostics while also playing a therapeutic role. This review was based on recent articles on multifunctional sonosensitizers that were used in SDT for the treatment of cancer and have the potential for clinical USI, CT, and MRI applications. Next, some of the shortcomings of the clinical examination and the results of sonosensitizers in animal imaging were described. Finally, this paper attempted to inform the future development of sonosensitizers in the field of integrative diagnostics and therapeutics and to point out current problems and prospects for their application.

Research Progress in Oxygen Carrier Design and Application

Ischemia or hypoxia can lead to pathological changes in the metabolism and function of tissues and then lead to various diseases. Timely and effective blood resuscitation or improvement of hypoxia is very important for the treatment of diseases. However, there is a need to develop stable, nontoxic, and immunologically inert oxygen carriers due to limitations such as blood shortages, different blood types, and the risk of transmitting infections. With the development of various technologies, oxygen carriers based on hemoglobin and perfluorocarbon have been widely studied in recent years. This paper reviews the development and application of hemoglobin and perfluorocarbon oxygen carriers. The design of oxygen carriers was analyzed, and their application as blood substitutes or oxygen carriers in various hypoxic diseases was discussed. Finally, the characteristics and future research of ideal oxygen carriers were prospected to provide reference for follow-up research.

Ultrasound Triggered Tumor Metabolism Suppressor Induces Tumor Starvation for Enhanced Sonodynamic Immunotherapy of Breast Cancer

Introduction

Sonodynamic therapy (SDT) as an emerging tumor treatment gained wide attention. However, tumor vascular destruction and oxygen depletion in SDT process may lead to further hypoxia. This may lead to enhanced glycolysis, lactate accumulation, and immunosuppression.

Methods

A glycolysis inhibitor (3PO) loaded and PEG modified black phosphorus nanosheets (BO) is constructed for potent starvation therapy and efficient immune activation.

Results

Under ultrasound irradiation, the BO can produce ROS to destroy tumors and tumor blood vessels and lead to further hypoxia and nutrients block. Then, the released 3PO inhibits tumor glycolysis and prevents the hypoxia-induced glycolysis and lactate accumulation. Both SDT and 3PO can cut off the source of lactic acid, as well as achieve antitumor starvation therapy through the blockade of the adenosine triphosphate (ATP) supply. In addition, the combination of starvation treatment and SDT further facilitates dendritic cells (DC) maturation, promotes antigen presentation by DCs, and eventually propagates the antitumor immunity and inhibition of abscopal tumor growth.

Conclusion

This is the first time that combines SDT with inhibition of glycolysis, achieving admirable tumor treatment and decreasing adverse events caused by SDT process and that has caused good immune activation. Our system provides a new idea for the future design of anti-tumor nanomedicines.

Formulation and Evaluation on Synergetic Anti-Hepatoma Effect of a Chemically Stable and Release-Controlled Nanoself-Assembly with Natural Monomers

Introduction

Hepatoma is the leading cause of death among liver diseases worldwide. Modern pharmacological studies suggest that some natural monomeric compounds have a significant effect on inhibiting tumor growth. However, poor stability and solubility, and side effects are the main factors limiting the clinical application of natural monomeric compounds.

Methods

In this paper, drug-co-loaded nanoself-assemblies were selected as a delivery system to improve the chemical stability and solubility of Tanshinone II A and Glycyrrhetinic acid, and to produce a synergetic anti-hepatoma effect.

Results

The study suggested that the drug co-loaded nanoself-assemblies showed high drug loading capacity, good physical and chemical stability, and controlled release. In vitro cell experiments verified that the drug-co-loaded nanoself-assemblies could increase the cellular uptake and cell inhibitory activity. In vivo studies verified that the drug co-loaded nanoself-assemblies could prolong the MRT_0-∞, increase accumulation in tumor and liver tissues, and show strong synergistic anti-tumor effect and good bio-safety in H22 tumor-bearing mice.

Conclusion

This work indicates that natural monomeric compounds co-loaded nanoself-assemblies would be a potential strategy for the treatment of hepatoma.

A type I AIE photosensitiser-loaded biomimetic nanosystem allowing precise depletion of cancer stem cells and prevention of cancer recurrence after radiotherapy

Radioresistance of Cancer stem cell (CSC) is an important cause of tumor recurrence after radiotherapy (RT). Herein, we designed a type I aggregation-induced emission (AIE) photosensitiser-loaded biomimetic mesoporous organosilicon nanosystem (PMT) for precise depletion of CSC to prevent tumor recurrence after RT. This PMT system is composed of a type I AIE photosensitiser (TBP-2) loaded mesoporous organosilicon nanoparticles (MON) with an outer platelet membrane. The PMT system is able to specifically target CSC. Intracellular glutathione activity leads to MON degradation and the release of TBP-2. Type I photodynamic therapy is activated by exposure to white light, producing a large amount of hydroxyl radicals to promote CSC death. The results of in vivo experiments demonstrated specific removal of CSC following PMT treatment, with no tumor recurrence observed when combined with RT. However, tumor recurrence was observed in mice that received RT only. The expression of CSC markers was significantly reduced following PMT treatment. We demonstrate the development of a system for the precise removal of CSC with good biosafety and high potential for clinical translation. We believe the PMT nanosystem represents a novel idea in the prevention of tumor recurrence.

Modulating the local coordination environment of cobalt single-atomic nanozymes for enhanced catalytic therapy against bacteria

Single-atomic nanozymes (SANZs) characterized by atomically dispersed single metal atoms have recently contributed to breakthroughs in biomedicine due to their satisfactory catalytic activity and superior selectivity compared to their nanoscale counterparts. The catalytic performance of SANZs can be improved by modulating their coordination structure. Therefore, adjusting the coordination number of the metal atoms in the active center is a potential method for enhancing the catalytic therapy effect. In this study, we synthesized various atomically dispersed Co nanozymes with different nitrogen coordination numbers for peroxidase (POD)-mimicking single-atomic catalytic antibacterial therapy. Among the single-atomic Co nanozymes with nitrogen coordination numbers of 3 (SACNZs-N₃-C) and 4 (SACNZs-N₄-C), single-atomic Co nanozymes with a coordination number of 2 (SACNZs-N₂-C) had the highest POD-like catalytic activity. Kinetic assays and Density functional theory (DFT) calculations indicated that reducing the coordination number can lower the reaction energy barrier of single-atomic Co nanozymes (SACNZs-N_x-C), thereby increasing their catalytic performance. In vitro and in vivo antibacterial assays demonstrated that SACNZs-N₂-C had the best antibacterial effect. This study provides proof of concept for enhancing single-atomic catalytic therapy by regulating the coordination number for various biomedical applications, such as tumor therapy and wound disinfection. STATEMENT OF SIGNIFICANCE: The use of nanozymes that contain single-atomic catalytic sites has been shown to effectively promote the healing of bacteria-infected wounds by exhibiting peroxidase-like activity. The homogeneous coordination environment of the catalytic site has been associated with high antimicrobial activity, which provides insight into designing new active structures and understanding their mechanisms of action. In this study, we designed a series of cobalt single-atomic nanozymes (PSACNZs-N_x-C) with different coordination environments by shearing the Co-N bond and modifying polyvinylpyrrolidone (PVP). The synthesized PSACNZs-N_x-C demonstrated enhanced antibacterial activity against both Gram-positive and Gram-negative bacterial strains, and showed good biocompatibility in both in vivo and in vitro experiments.

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

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

A Light-Responsive Injectable Hydrogel with Remodeling Tumor Microenvironment for Light-Activated Chemodynamic Therapy

Chemodynamic therapy (CDT) based on Fenton-like reaction is often limited by the tumor microenvironment (TME), which has insufficient hydrogen peroxide, and single CDT treatment is often less efficacious. To overcome these limitations, a hydrogel-based system is designed to enhance the redox stress (EOH) by loading the composite nanomaterial Cu-Hemin-Au, into the agarose hydrogels. The hydrogels can reach the tumor site upon intratumoral injection, and then coagulate and stay for extended period. Once irradiated with near-infrared light, the Cu-Hemin-Au act as a photothermal agent to convert the light energy into heat, and the EOH gradually heated up and softened, releasing the Cu-Hemin-Au residing in it to achieve photothermal therapy (PTT). Benefiting from the glucose oxidase (GOx)-like activity of the Au nanoparticles, glucose in the tumor cells is largely consumed, and hydrogen peroxide (H₂ O₂ ) is generated in situ, and then Cu-Hemin-Au react with sufficient H₂ O₂ to generate a large amount of reactive oxygen species, which promote the complete inhibition of tumor growth in mice during the treatment cycle. The hydrogel system for the synergistic enhancement of oxidative stress achieves good PTT/CDT synergy, providing a novel inspiration for the next generation of hydrogels for application in antitumor therapy.

Newly developed gas-assisted sonodynamic therapy in cancer treatment

Sonodynamic therapy (SDT) is an emerging noninvasive treatment modality that utilizes low-frequency and low-intensity ultrasound (US) to trigger sensitizers to kill tumor cells with reactive oxygen species (ROS). Although SDT has attracted much attention for its properties including high tumor specificity and deep tissue penetration, its anticancer efficacy is still far from satisfactory. As a result, new strategies such as gas-assisted therapy have been proposed to further promote the effectiveness of SDT. In this review, the mechanisms of SDT and gas-assisted SDT are first summarized. Then, the applications of gas-assisted SDT for cancer therapy are introduced and categorized by gas types. Next, therapeutic systems for SDT that can realize real-time imaging are further presented. Finally, the challenges and perspectives of gas-assisted SDT for future clinical applications are discussed.

'Mito-Bomb': a novel mitochondria-targeting nanosystem for ferroptosis-boosted sonodynamic antitumor therapy

Mitochondria play an important role in regulating tumor cell death and metabolism so that they can be potential therapeutic targets. Sonodynamic therapy (SDT) represents an attractive antitumor method that induces apoptosis by producing highly toxic reactive oxygen species (ROS). Mitochondria-targeting SDT can cause oxidative damage and improve the efficiency of tumor therapy. However, due to the nonselective distribution of nanosystems and the anti-apoptotic mechanism of cancer cells, the therapeutic effect of SDT is not ideal. Therefore, we proposed a novel mitochondria-targeting nanosystem (‘Mito-Bomb’) for ferroptosis-boosted SDT. Sonosensitizer IR780 and ferroptosis activator RSL-3 were both encapsulated in biocompatible poly(lactic‐co‐glycolic acid) (PLGA) nanoparticles to form ‘Mito-Bomb’ (named IRP NPs). IR780 in this nanosystem was used to mediate mitochondria-targeting SDT. RSL-3 inhibited the activity of GPX4 in the antioxidant system to induce ferroptosis of tumor cells, which could rewire tumor metabolism and make tumor cells extremely sensitive to SDT-induced apoptosis. Notably, we also found that RSL-3 can inhibit hypoxia inducible factor-1α (HIF-1α) and induce ROS production to improve the efficacy of SDT to synergistically antitumor. RSL-3 was applied as a ‘One-Stone-Three-Birds’ agent for cooperatively enhanced SDT against triple-negative breast cancer. This study presented the first example of RSL-3 boosting mitochondria-targeting SDT as a ferroptosis activator. The ‘Mito-Bomb’ biocompatible nanosystem was expected to become an innovative tumor treatment method and clinical transformation.

Colon cancer exosome-derived biomimetic nanoplatform for curcumin-mediated sonodynamic therapy and calcium overload

Sonodynamic therapy (SDT) possesses unique properties such as being minimally invasive, exhibiting low toxicity, as well as ability to impart the treatment in the deep tissues, and hence has been extensively used. However, inherent defects such as low water-soluble sonosensitizers can limit the clinical application of SDT, and tumor microenvironment (TME) can further compromise the effect of a single SDT. To overcome these challenges, we have designed a bionic nano-system (ECaC) by coating mesoporous calcium carbonate nanoparticles (CaCO3 NPs) and sonosensitizer curcumin (Cur) into tumor-derived exosomes for developing enhanced SDT. Exosome membrane could endow CaCO3 NPs with homologous targeting abilities. In addition, compared with the bare CaCO3 NPs, ECaC showed significant accumulation in the tumor cell species. Subsequently, CaCO3 NPs upon reaching the tumor site can be degraded into Ca2+ in response to the acidic microenvironment of the tumor to destroy the cellular mitochondria. Hence, the cellular respiration could be destroyed to be a vulnerable state, causing oxidative stress, enhancing Cur-mediated chemotherapy/SDT. This synergistically dynamic therapy has demonstrated significant anti-tumor effects under in vitro and in vivo settings without exhibiting any toxic side effects. Our prepared biomimetic nano-system can effectively deliver the hydrophobic Cur to the tumor sites, which holds great promise in field of drug delivery and can broaden the application of exosomes, as this method has a certain enlightenment effect on the subsequent development of exosomes.

A novel dual MoS2/FeGA quantum dots endowed injectable hydrogel for efficient photothermal and boosting chemodynamic therapy

Due to its responsiveness to the tumour microenvironment (TME), chemodynamic therapy (CDT) based on the Fenton reaction to produce cytotoxic reactive oxygen species (ROS) to destroy tumor has drawn more interest. However, the Fenton's reaction potential for therapeutic use is constrained by its modest efficacy. Here, we develop a novel injectable hydrogel system (FMH) on the basis of FeGA/MoS2 dual quantum dots (QDs), which uses near-infrared (NIR) laser in order to trigger the synergistic catalysis and photothermal effect of FeGA/MoS2 for improving the efficiency of the Fenton reaction. Mo4+ in MoS2 QDs can accelerate the conversion of Fe3+ to Fe2+, thereby promoting the efficiency of Fenton reaction, and benefiting from the synergistically enhanced CDT/PTT, FMH combined with NIR has achieved good anti-tumour effects in vitro and in vivo experiments. Furthermore, the quantum dots are easily metabolized after treatment because of their ultrasmall size, without causing any side effects. This is the first report to study the co-catalytic effect of MoS2 and Fe3+ at the quantum dot level, as well as obtain a good PTT/CDT synergy, which have implications for future anticancer research.

Manganese-based hollow nanoplatforms for MR imaging-guided cancer therapies

Theranostic nanoplatforms integrating diagnostic and therapeutic functions have received considerable attention in the past decade. Among them, hollow manganese (Mn)-based nanoplatforms are superior since they combine the advantages of hollow structures and the intrinsic theranostic features of Mn²⁺. Specifically, the hollow cavity can encapsulate a variety of small-molecule drugs, such as chemotherapeutic agents, photosensitizers and photothermal agents, for chemotherapy, photodynamic therapy (PDT) and photothermal therapy (PTT), respectively. After degradation in the tumor microenvironment (TME), the released Mn²⁺ is able to act simultaneously as a magnetic resonance (MR) imaging contrast agent (CA) and as a Fenton-like agent for chemodynamic therapy (CDT). More importantly, synergistic treatment outcomes can be realized by reasonable and optimized design of the hollow nanosystems. This review summarizes various Mn-based hollow nanoplatforms, including hollow Mn_xO_y, hollow matrix-supported Mn_xO_y, hollow Mn-doped nanoparticles, hollow Mn complex-based nanoparticles, hollow Mn-cobalt (Co)-based nanoparticles, and hollow Mn-iron (Fe)-based nanoparticles, for MR imaging-guided cancer therapies. Finally, we discuss the potential obstacles and perspectives of these hollow Mn-based nanotheranostics for translational applications.

Nanozyme Hydrogels for Self-Augmented Sonodynamic/Photothermal Combination Therapy

Sonosensitizer-mediated sonodynamic therapy (SDT) has emerged as a promising anti-tumor strategy. However, this strategy of continuous oxygen consumption further exacerbates the hypoxic tumor microenvironment, which limits its therapeutic efficacy. In this study, we designed a multifunctional hydrogel (PB+Ce6@Hy) that simultaneously co-delivers nanozyme prussian blue (PB) and sonosensitizer chlorin e6 (Ce6) for the realization of photothermal therapy (PTT) and enhanced SDT. When the hydrogel reaches the tumor tissue through local injection, the 808 nm laser can induce the hydrogel to warm up and soften, thereby triggering the release of PB and Ce6. PB can interact with endogenous H₂O₂in situ and generate sufficient oxygen to promote the Ce6-mediated SDT effect. Besides, due to the good encapsulation ability of the hydrogel, the nanomaterials can be released in a controlled manner by changing laser parameter, irradiation time, etc. The experimental results show that the PB+Ce6@Hy system we developed can generate a large amount of reactive oxygen species (ROS), which can be combined with the photothermal effect to kill tumor cells, as a result, tumor proliferation has been adequately inhibited. This combined PTT/SDT dynamic strategy provides a new perspective for Ce6-induced cancer therapy, showing great potential for clinical application.

Enhanced Glioblastoma Selectivity of Harmine via the Albumin Carrier

Glioblastoma, the most common tumor in the brain, has witnessed very little clinical progress over the last decades. Exploring and discovering new therapeutic strategies for glioblastoma has become a critical problem. Harmine (HM), belonging to the beta-carboline alkaloid, is a natural product and isolated from the seeds of Peganum harmala L., which own notable antitumor activity in vitro. However, the poor water solubility and less selectivity of HM severely limit its clinical use. For enhancing its selective ability to tumor cells, we fabricated a kind of protein nanoparticles (BSA-HM NPs), composed of the modified bovine serum albumin (BSA) and HM. It was substantiated through in vitro and in vivo experiment that BSA-HM NPs could predominantly accumulate in tumor tissues and exhibited remarkably enhanced antitumor efficacy. This study provides a promising strategy to improve the bioavailability and avoid side effects of HM as antitumor agents by choosing BSA as carriers.