Nanozyme Hydrogels for Self-Augmented Sonodynamic/Photothermal Combination Therapy

Nanotechnology-enabled sonodynamic therapy against malignant tumors

Sonodynamic therapy (SDT) is an emerging approach for malignant tumor treatment, offering high precision, deep tissue penetration, and minimal side effects. The rapid advancements in nanotechnology, particularly in cancer treatment, have enhanced the efficacy and targeting specificity of SDT. Combining sonodynamic therapy with nanotechnology offers a promising direction for future cancer treatments. In this review, we first systematically discussed the anti-tumor mechanism of SDT and then summarized the common nanotechnology-related sonosensitizers and their recent applications. Subsequently, nanotechnology-related therapies derived using the SDT mechanism were elaborated. Finally, the role of nanomaterials in SDT combined therapy was also introduced.

Neuromodulation by nanozymes and ultrasound during Alzheimer's disease management

Alzheimer's disease (AD) is a neurodegenerative disorder with complex pathogenesis and effective clinical treatment strategies for this disease remain elusive. Interestingly, nanomedicines are under extensive investigation for AD management. Currently, existing redox molecules show highly bioactive property but suffer from instability and high production costs, limiting clinical application for neurological diseases. Compared with natural enzymes, artificial enzymes show high stability, long-lasting catalytic activity, and versatile enzyme-like properties. Further, the selectivity and performance of artificial enzymes can be modulated for neuroinflammation treatments through external stimuli. In this review, we focus on the latest developments of metal, metal oxide, carbon-based and polymer based nanozymes and their catalytic mechanisms. Recent developments in nanozymes for diagnosing and treating AD are emphasized, especially focusing on their potential to regulate pathogenic factors and target sites. Various applications of nanozymes with different stimuli-responsive features were discussed, particularly focusing on nanozymes for treating oxidative stress-related neurological diseases. Noninvasiveness and focused application to deep body regions makes ultrasound (US) an attractive trigger mechanism for nanomedicine. Since a complete cure for AD remains distant, this review outlines the potential of US responsive nanozymes to develop future therapeutic approaches for this chronic neurodegenerative disease and its emergence in AD management.

Magnetically actuated sonodynamic nanorobot collectives for potentiated ovarian cancer therapy

Ovarian cancer presents a substantial challenge due to its high mortality and recurrence rates among gynecological tumors. Existing clinical chemotherapy treatments are notably limited by drug resistance and systemic toxic side effects caused by off target drugs. Sonodynamic therapy (SDT) has emerged as a promising approach in cancer treatment, motivating researchers to explore synergistic combinations with other therapies for enhanced efficacy. In this study, we developed magnetic sonodynamic nanorobot (Fe3O4@SiO2-Ce6, FSC) by applying a SiO2 coating onto Fe3O4 nanoparticle, followed by coupling with the sonosensitizer Ce6. The magnetic FSC nanorobot collectives could gather at fixed point and actively move to target site regulated by magnetic field. In vitro experiments revealed that the magnetic FSC nanorobot collectives enabled directional navigation to the tumor cell area under guidance. Furthermore, under low-intensity ultrasonic stimulation, FSC nanorobot collectives mediated sonodynamic therapy exhibited remarkable anti-tumor performance. These findings suggest that magnetically actuated sonodynamic nanorobot collectives hold promising potential for application in target cancer therapy.

Nanozyme: a rising star for cancer therapy

In recent years, nanozymes have attracted enormous attention due to their effectiveness in promoting various catalytic reactions. To date, thousands of nanozymes have been discovered, including oxidase-like nanozymes, peroxidase-like nanozymes, and catalase-like nanozymes, covering noble metal, transition metal, and carbon nanomaterials. These nanozymes have been widely applied in various fields, including environmental protection, biosensing and nanomedicine. There are many reviews about this rising star being used in analytical chemistry. However, few works about nanozymes were related to cancer therapy. In this study, we comprehensively summarize the latest research advances on the strategies for cancer therapy based on different nanozymes. With traditional cancer treatment (including chemotherapy, radiotherapy, phototherapy), nanozyme catalytic therapy exhibited a synergistic effect for limiting the growth of tumors. Opportunities and trends for nanozymes in future cancer therapy are also discussed.

Cu-doped polypyrrole hydrogel with tumor catalyst activity for NIR-II thermo-radiotherapy

Introduction: Radiotherapy (RT) is one of the key methods for treating breast cancer. However, the effect of single RT is often poor because of insufficient deposition of X-rays in tumor sites and radiation resistance induced by the abnormal tumor microenvironment (overexpression of glutathione (GSH)). The development of multifunctional RT sensitizers and synergetic therapeutic strategies is, therefore, a promising area for enhancing the anticancer effect of RT. Methods: In this study, a multifunctional nanozyme hydrogel based on Cu-doped polypyrrole (CuP) was designed to work concertedly with a second near-infrared thermal RT. The CuP-based hydrogel (CH) reached the tumor site when injected in-situ and achieved long-term storage. Results: Once stimulated with 1064-nm laser irradiation, the heated and softened hydrogel system released CuP nanozyme to provide photothermal therapy, thereby inhibiting the repair of DNA damage caused by RT. In addition, CuP with dual nanozyme activity depleted the intracellular GSH to reduce the antioxidant capacity of the tumor. Moreover, CuP converted H₂O₂ to produce ·OH to directly kill the tumor cells, thus enhancing the capability of low-dose RT to inhibit tumor growth. In vivo experiments showed that the CH system used in combination with a low-power 1064-nm laser and low-dose RT (4 Gy) exhibited good synergistic anticancer effects and biological safety. Discussion: As a new light-responsive hydrogel system, CH holds immense potential for radio-sensitization.

The multifunctional Prussian blue/graphitic carbon nitride nanocomposites for fluorescence imaging-guided photothermal and photodynamic combination therapy

Cancer has been regarded as one of the most intractable diseases worldwide and threatens human health and life. Photothermal/Photodynamic therapy (PTT and PDT) have emerged as reliable and effective strategies in cancer treatment with the superiorities of non-invasiveness, slight side effects, and high treatment efficiency. Herein, a nanocomposite (PBCN) was fabricated via electrostatic interaction between Prussian blue nanoparticles (PBNPs) and graphitic carbon nitride (g-C₃N₄), and the resulting PBCN possessed good photothermal properties and excellent photodynamic effects with 808 nm irradiation. Furthermore, it exhibits excellent fluorescence imaging ability in cells, highlighting its potential as a powerful imaging agent in the biomedical field. Combination with a photothermal material, photosensitizer, and fluorescence imaging agent would thus allow PBCN to realize fluorescence imaging-guided PTT/PDT, showing an outstanding theranostic effect on cancer cells.

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.