Activation and Monitoring of mtDNA Damage in Cancer Cells via the "Proton-Triggered" Decomposition of an Ultrathin Nanosheet

Application of capsaicin and calcium phosphate-loaded MOF system for tumor therapy involving calcium overload

Calcium overload therapy refers to the condition of intracellular Ca2+ overload, which causes mitochondrial damage and leads to the uncontrolled release of apoptotic factors into the cytoplasm through the open mitochondrial permeability pore. Based on this, it is playing an increasingly important role in the field of oncology due to its good efficacy and small side effects. However, the regulation of calcium homeostasis by cancer cells themselves, insufficient calcium ions (Ca2+) in tumor sites and low efficiency of calcium entering tumor have limited its efficacy, resulting in unsatisfactory therapeutic effect. Therefore, a novel CAP/BSA@TCP-ZIF-8 nanoparticle drug carrier system was constructed that can provide Ca2+ from exogenous sources for pH-controlled degradation and drug release at the same time. Both in vivo and in vitro experiments have proved that the nanomaterial can activate TRPV1 channels and provide exogenous Ca2+ to cause Ca2+ overload and apoptosis, thus achieving anti-tumor effects.

Aspect ratio-dependent dual-regulation of the tumor immune microenvironment against osteosarcoma by hydroxyapatite nanoparticles

Accumulating studies demonstrated that hydroxyapatite nanoparticles (HANPs) showed a selective anti-tumor effect, making them a good candidate for osteosarcoma (OS) treatment. However, the capacity of HANPs with different aspect ratios to regulate tumor immune microenvironment (TIM) was scarcely reported before. To explore it, the three HANPs with aspect ratios from 1.86 to 6.25 were prepared by wet chemical method. After a 24 or 72 h-exposure of OS UMR106 cells or macrophages to the nanoparticles, the tumor cells exhibited immunogenic cell death (ICD) indicated by the increased production of calreticulin (CRT), adenosine triphosphate (ATP) and high mobility group box 1 (HMGB1), and macrophages were activated with the release of pro-inflammatory cytokines. Next, the beneficial crosstalk between tumor cells and macrophages generated in the presence of HANPs for improved anti-tumor immunity activation. In the OS-bearing cognate rat model, HANPs inhibited OS growth, which was positively correlated with CRT and HMGB1 expression, and macrophage polarization in the tumor tissues. Additionally, HANPs promoted CD8+ T cell infiltration into the tumor and systemic dendritic cell maturation. Particularly, HANPs bearing the highest aspect ratio exhibited the strongest immunomodulatory and anti-tumor function. This study suggested the potential of HANPs to be a safe and effective drug-free nanomaterial to control the TIM for OS therapy. STATEMENT OF SIGNIFICANCE: Emerging studies demonstrated that hydroxyapatite nanoparticles (HANPs) inhibited tumor cell proliferation and tumor growth. However, the underlying anti-tumor mechanism still remains unclear, and the capacity of HANPs without any other additive to regulate tumor immune microenvironment (TIM) was scarcely reported before. Herein, we demonstrated that HANPs, in an aspect ratio-dependent manner, showed the potential to delay the growth of osteosarcoma (OS) and to regulate TIM by promoting the invasion of CD8+ T cells and F4/80+ macrophages, and inducing immunogenic cell death (ICD) in tumors. This work revealed the new molecular mechanism for HANPs against OS, and suggested HANPs might be a novel ICD inducer for OS treatment.

Photoinduced electron transfer (PeT) based fluorescent probes for cellular imaging and disease therapy

Typical PeT-based fluorescent probes are multi-component systems where a fluorophore is connected to a recognition/activating group by an unconjugated linker. PeT-based fluorescent probes are powerful tools for cell imaging and disease diagnosis due to their low fluorescence background and significant fluorescence enhancement towards the target. This review provides research progress towards PeT-based fluorescent probes that target cell polarity, pH and biological species (reactive oxygen species, biothiols, biomacromolecules, etc.) over the last five years. In particular, we emphasise the molecular design strategies, mechanisms, and application of these probes. As such, this review aims to provide guidance and to enable researchers to develop new and improved PeT-based fluorescent probes, as well as promoting the use of PeT-based systems for sensing, imaging, and disease therapy.

Engineering Chemotherapeutic-Augmented Calcium Phosphate Nanoparticles for Treatment of Intraperitoneal Disseminated Ovarian Cancer

Ovarian cancer is a common gynecologic malignancy with a high fatality rate. Intraperitoneal chemotherapy has been proved as an efficient clinical treatment for disseminated ovarian cancer. However, there are limitations for conventional small molecule drugs to achieve an ideal therapeutic effect. Herein, a synergistic treatment for intraperitoneally disseminated ovarian cancer was achieved by Arg-Gly-Asp (RGD)-modified amorphous calcium phosphate loading with doxorubicin (designated as RGD-CaPO/DOX). The engineered calcium-involved nanomedicine augmented the therapeutic effect of DOX by aggravating endoplasmic reticulum stress, calcium overload, and mitochondrial dysfunction, ultimately triggering mitochondrial apoptosis in the SKOV3 (human ovarian cancer) cell line. In an intraperitoneally disseminated tumor model, RGD modification and the weak negative surface potential of the NPs were beneficial for intraperitoneal retention and tumor targeting. Moreover, intraperitoneal injection of RGD-CaPO/DOX NPs resulted in a favorable antitumor effect. The mean survival time of SKOV3-bearing mice was significantly extended from 29 to 59 days with negligible toxicity. Therefore, this study has been designed to provide an effective chemotherapeutic-augmented treatment for intraperitoneally disseminated ovarian cancer.

Nanoplatform-mediated calcium overload for cancer therapy

Mitochondria, as the "the plant of power" of cells, have been extensively highlighted with biological functions of offering energy and participating in signaling pathways. In parallel, calcium (Ca2+) plays a...