H2O2 Self-Supply and Glutathione Depletion Engineering Nanoassemblies for NIR-II Photoacoustic Imaging of Tumor Tissues and Photothermal-Enhanced Gas Starvation-Primed Chemodynamic Therapy

The development of tumor microenvironment (TME)-activated nanoassemblies which can produce a photoacoustic (PA) signal and enhance the H2O2 level is critical to achieve accurate diagnosis and highly efficient chemodynamic therapy (CDT). In this study, we developed nanoassemblies consisting of oxygen vacancy titanium dioxide (TiO2-x) surface-constructed copper, sulfur-doped mesoporous organosilica and glucose oxidase (TiO2-x@Cu,S-MONs@GOx, hereafter TMG). We found that highly abundant glutathione (GSH) in the TME nanoassemblies can reduce tetrasulfide bonds and Cu2+ to sulfur ions and Cu+ in the TMG nanoassemblies, respectively, causing the breakage of the tetrasulfide bond and the mesoporous structure collapse, releasing Cu+ ions and TiO2-x nanoparticles, and producing hydrogen sulfide gas, thereby achieving synergistic multimodal tumor treatment through TME-activated NIR-II PA imaging and photothermal-enhanced gas starvation-primed CDT. Therefore, the TMG nanoassemblies form a smart nanoplatform that can serve as an excellent tumor diagnosis-treatment agent by playing an important role in imaging-guided precision diagnosis of cancer and efficient targeting treatment.

A multi-responsive targeting drug delivery system for combination photothermal/chemotherapy of tumor

To achieve efficient delivery and precise release of chemotherapy drugs at tumor sites, an active targeting multi-responsive drug delivery platform was developed. Here, doxorubicin hydrochloride (DOX) was loaded onto polydopamine (PDA), which were coated by the cystamine-modified hyaluronic acid (HA-Cys), designated as DOX@PDA-HA (PDH). The combination of PDA and HA-Cys endowed the nanoplatform photothermal conversion, tumor-targeting, and pH/redox/NIR sensitive drug release capacity. Moreover, HA could be degraded by the excess hyaluronidase (HAase) in the tumor microenvironment (TME), promoting DOX release, and further enhancing the effect of chemotherapy. Experimental results demonstrated PDH good biocompatibility, high loading rate, targeted drug delivery, and efficient tumor cell killing ability. This ingenious strategy based on PDH showed huge potential in photothermal/chemotherapy combination treatment of cancer.

Glutamine coated titanium for synergistic sonodynamic and photothermal on tumor therapy upon targeted delivery

Introduction: The application of titanium dioxide nanoparticles (TiO₂ NPs) for cancer therapy has been studied for decades; however, the targeted delivery of TiO₂ NPs to tumor tissues is challenging, and its efficiency needs to be improved. Method: In this study, we designed an oxygen-deficient TiO_2-x coated with glutamine layer for targeted delivery, as well as the enhanced separation of electrons (e-) and holes (h+) following the joint application of sonodynamic therapy (SDT) and photothermal therapy (PTT). Results: This oxygen-deficient TiO_2-x possesses relatively high photothermal and sonodynamic efficiency at the 1064 nm NIR-II bio-window. The GL-dependent design eased the penetration of the TiO_2-x into the tumor tissues (approximately three-fold). The in vitro and in vivo tests showed that the SDT/PTT-based synergistic treatment achieved more optimized therapeutic effects than the sole use of either SDT or PTT. Conclusion: Our study provided a safety targeted delivery strategy, and enhanced the therapeutic efficiency of SDT/PTT synergistic treatment.

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.

Amplifying Dendritic Cell Activation by Bioinspired Nanometal Organic Frameworks for Synergistic Sonoimmunotherapy

Despite recent advancements of sonodynamic therapy (SDT) in cancer immunotherapy, challenges have yet to be surmounted to further boost its immunotherapeutic efficacy due to the low-level tumor antigens presentation of dendritic cells (DCs). Cell membrane camouflaged-nanoparticles can integrate the neoantigens of the cancer cell membrane with the multifunctionalities of synthetic nanocores. Herein, sono-responsive nanoparticles coated with DC-targeted antibody chimeric cancer cell membrane are investigated for multimodal therapy. The nanometal organic frameworks (MOFs) that respond to ultrasound are loaded successfully inside the vesicles displaying an anti-DEC205 antibody. The anti-DEC205 chimeric vesicles can directly target and activate DCs, promote tumor antigens cross-presentation, and then produce a cascade amplified T-cell immune response. Upon deep tissue-penetrating sonication, AMR-MOF@AuPt generates large amounts of reactive oxygen species that directly kill cancer cells, further initiating an anti-cancer T cell immune response. Such synergistic sono-immunotherapies effectually inhibit tumor growth and induce strong systemic and long-term immune memory against cancer recurrence and distant metastasis. The authors findings provide DCs and tumor cells of a dual active-targeting cell membrane-coated sono-immunotherapeutic nanoplatform for cancer therapy.

TiSe2-mediated sonodynamic and checkpoint blockade combined immunotherapy in hypoxic pancreatic cancer

Background

Pancreatic cancer remains among the most prevalent and aggressive forms of cancer. While immunotherapeutic treatment strategies have shown some promise in affected patients, the benefits of these interventions have been limited by insufficient tumor infiltration by activated T cells.

Results

Here, Titanium diselenide (TiSe₂) nanosheets were synthesized with good stability. When exposed to ultrasound (US), the TiSe₂ nanosheets served as a reliable nano-sensitizer capable of inducing large amounts of reactive oxygen species (ROS) mediating sonodynamic therapy (SDT) under hypoxic and normoxic conditions. The tumor-released TAAs induced by TiSe₂ nanosheet-mediated SDT promoted immunogenic cell death (ICD) conducive to the maturation of dendritic cells (DCs), and cytokine secretion and the subsequent activation and infiltration of T cells into the tumor. Combining TiSe₂-mediated SDT with anti-PD-1 immune checkpoint blockade treatment led to the efficient suppression of the growth of both primary tumor and distant tumor, while simultaneously preventing lung metastasis. These improved immunotherapeutic and anti-metastatic outcomes were associated with activated systematic antitumor immune responses, including the higher levels of DC maturation and cytokine secretion, the increased levels of CD8⁺ T cells and the decreased levels of T_reg cells infiltrated in tumors.

Conclusion

TiSe₂ can be used as a sonosensitizer with good efficacy and high safety to mediate efficient SDT. The combination treatment strategy comprised of TiSe₂-mediated SDT and PD-1 blockade activate anti-tumor immune responses effectively thorough inducing ICD, resulting in the inhibition the growth and metastasis of tumor. The combination therapy holds promise as a novel immunotherapy-based intervention strategy for pancreatic cancer patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01659-4.

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.

Advanced biotechnology-assisted precise sonodynamic therapy

Despite significant advances, the therapeutic impact of photodynamic therapy is still substantially hampered by the restricted penetration depth of light and the reactive oxygen species (ROS)-mediated toxicity, which is impeded by the shorter effective half-life and radius of ROS produced during treatment. Sonodynamic therapy (SDT), on the other hand, provides unrivalled benefits in deep-seated tumour ablation due to its deep penetration depth and not totally ROS-dependent toxicity, exhibiting enormous preclinical and clinical potential. In this tutorial review, we highlight imaging-guided precise SDT, which allows choosing the best treatment option and monitoring the therapy response in real-time, as well as recent clinical trials based on SDT. Aside from that, the subtle design strategies of sonosensitizers based on tumour environment shaping and rational structure modification, as well as SDT combination treatment (chemotherapy, chemodynamic therapy, photodynamic therapy, photothermal therapy, gas therapy and immunotherapy), aimed at a more effective treatment outcome, are summarized. Finally, we discussed the future of SDT for personalized cancer and other disease treatments.