In vivo visualization of tumor-associated macrophages re-education by photoacoustic/fluorescence dual-modal imaging with a metal-organic frames-based caspase-1 nanoreporter.

Tumor-associated macrophages (TAMs) are vital in the tumor microenvironment, contributing to immunosuppression and therapy tolerance. Despite their importance, the precise re-education of TAMs in vivo continues to present a formidable challenge. Moreover, the lack of real-time and efficient methods to comprehend the spatiotemporal kinetics of TAMs repolarization remains a significant hurdle, severely hampering the accurate assessment of treatment efficacy and prognosis. Herein, we designed a metal-organic frameworks (MOFs) based Caspase-1 nanoreporter (MCNR) that can deliver a TLR7/8 agonist to the TAMs and track time-sensitive Caspase-1 activity as a direct method to monitor the initiation of immune reprogramming. This nanosystem exhibits excellent TAMs targeting ability, enhanced tumor accumulation, and stimuli-responsive behavior. By inducing the reprogramming of TAMs, they were able to enhance T-cell infiltration in tumor tissue, resulting in inhibited tumor growth and improved survival in mice model. Moreover, MCNR also serves as an activatable photoacoustic and fluorescent dual-mode imaging agent through Caspase-1-mediated specific enzyme digestion. This feature enables non-invasive and real-time antitumor immune activation monitoring. Overall, our findings indicate that MCNR has the potential to be a valuable tool for tumor immune microenvironment remodeling and noninvasive quantitative detection and real-time monitoring of TAMs repolarization to immunotherapy in the early stage.

Tumor Microenvironment Activated Photoacoustic-Fluorescence Bimodal Nanoprobe for Precise Chemo-immunotherapy and Immune Response Tracing of Glioblastoma.

Synergistic therapy strategy and prognostic monitoring of glioblastoma's immune response to treatment are crucial to optimize patient care and advance clinical outcomes. However, current systemic temozolomide (TMZ) chemotherapy and imaging methods for in vivo tracing of immune responses are inadequate. Herein, we report an all-in-one theranostic nanoprobe (PEG/αCD25-Cy7/TMZ) for precise chemotherapy and real-time immune response tracing of glioblastoma by photoacoustic-fluorescence imaging. The nanoprobe was loaded with TMZ and targeted regulatory T lymphocyte optical dye αCD25-Cy7 encapsulated by glutathione-responsive DSPE-SS-PEG2000. The results showed that the targeted efficiency of the nanoprobe to regulatory T lymphocytes is up to 92.3%. The activation of PEG/αCD25-Cy7/TMZ by glutathione enhanced the precise delivery of TMZ to the tumor microenvironment for local chemotherapy and monitored glioblastoma's boundary by photoacoustic-fluorescence imaging. Immunotherapy with indoleamine 2,3-dioxygenase inhibitors after chemotherapy could promote immunological responses and reduce regulatory T lymphocyte infiltration, which could improve the survival rate. Photoacoustic imaging has in real-time and noninvasively depicted the dynamic process of immune response on a micrometer scale, showing that the infiltration of regulatory T lymphocytes after chemotherapy was up-regulated and would down-regulate after IDO inhibitor treatment. This all-in-one theranostic strategy is a promising method for precisely delivering TMZ and long-term dynamically tracing regulatory T lymphocytes to evaluate the immune response in situ for accurate tumor chemo-immunotherapy.

Mild photothermal/radiation therapy potentiates ferroptosis effect for ablation of breast cancer via MRI/PA imaging guided all-in-one strategy.

BACKGROUND: Nanotheranostics advances anticancer management by providing therapeutic and diagnostic functions, that combine programmed cell death (PCD) initiation and imaging-guided treatment, thus increasing the efficacy of tumor ablation and efficiently fighting against cancer. However, mild photothermal/radiation therapy with imaging-guided precise mediating PCD in solid tumors, involving processes related to apoptosis and ferroptosis, enhanced the effect of breast cancer inhibition is not fully understood. RESULTS: Herein, targeted peptide conjugated gold nano cages, iRGD-PEG/AuNCs@FePt NPs ternary metallic nanoparticles (Au@FePt NPs) were designed to achieve photoacoustic imaging (PAI)/Magnetic resonance imaging (MRI) guided synergistic therapy. Tumor-targeting Au@FePt forms reactive oxygen species (ROS), initiated by X-ray-induced dynamic therapy (XDT) in collaboration with photothermal therapy (PTT), inducing ferroptosis-augmented apoptosis to realize effective antitumor therapeutics. The relatively high photothermal conversion ability of Au@FePt increases the temperature in the tumor region and hastens Fenton-like processes to achieve enhanced synergistic therapy. Especially, RNA sequencing found Au@FePt inducting the apoptosis pathway in the transcriptome profile. CONCLUSION: Au@FePt combined XDT/PTT therapy activate apoptosis and ferroptosis related proteins in tumors to achieve breast cancer ablation in vitro and in vivo. PAI/MRI images demonstrated Au@FePt has real-time guidance for monitoring synergistic anti-cancer therapy effect. Therefore, we have provided a multifunctional nanotheranostics modality for tumor inhibition and cancer management with high efficacy and limited side effects.

Tumor-Homing and Immune-Reprogramming Cellular Nanovesicles for Photoacoustic Imaging-Guided Phototriggered Precise Chemoimmunotherapy.

Many studies have focused on developing effective therapeutic strategies to selectively destroy primary tumors, eliminate metastatic lesions, and prevent tumor recurrence with minimal side effects on normal tissues. In this work, we synthesized engineered cellular nanovesicles (ECNVs) with tumor-homing and immune-reprogramming functions for photoacoustic (PA) imaging-guided precision chemoimmunotherapy. M1-macrophage-derived cellular nanovesicles (CNVs) were loaded with gold nanorods (GNRs), gemcitabine (GEM), CpG ODN, and PD-L1 aptamer. The good histocompatibility and tumor-homing effect of CNVs improved drug retention in the bloodstream and led to their enrichment in tumor tissues. Furthermore, the photothermal ability of GNRs enabled PA imaging-guided drug release. GEM induced tumor immunogenic cell death (ICD), and CpG ODN promoted an immune response to the antigens released by ICD, leading to long-term specific antitumor immunity. In addition, the PD-L1 aptamer relieved the inhibitory effect of the PD1/PD-L1 checkpoint on CD8+ T-cells and augmented the immunotherapeutic effect. The synergistic innate and adaptive immune responses enhanced the antitumor effect of ECNVs. In summary, this nanoplatform integrates local targeted photothermal therapy with extensive progressive chemotherapy and uses ICD to reshape the immune microenvironment for tumor ablation.

Undifferentiated destruction of mitochondria by photoacoustic shockwave to overcome chemoresistance and radiation resistance in cancer therapy.

Resistance to either radiation or chemotherapy remains a complex and stubborn obstacle in cancer therapy and is responsible for a significant portion of the treatment failure. While the underlying mechanisms of the resistance are often associated with multiple factors, direct destruction of mitochondria is likely to ensure the ultimate death of the cell. Herein, a strategy of precise mitochondrial destruction using a photoacoustic (PA) shockwave was proposed to overcome chemoresistance and radiation resistance in cancer therapy. A nanoparticle featuring mitochondria-targeting and high near-infrared absorbance is constructed. The nanoparticle was found to indiscriminately localize in the mitochondria of both parental and its corresponding resistant tumor cells due to the mitochondrial transmembrane potential. By absorbing a controllable amount of energy from a pulsed laser, the nanoparticle could generate a mechanical PA shockwave that physically damages the mitochondria leading to the opening of apoptotic pathways and thus yielding a precision antitumor effect. The cell-killing efficiency was validated in vitro and in vivo. The results demonstrate that a PA shockwave can result in undifferentiated killing of the resistant tumor cells via destruction of mitochondria. Given the critical importance of resistant tumor cells, although at its preliminary stage, the proposed modality may open a new window in cancer therapy.

Photoacoustic-immune therapy with a multi-purpose black phosphorus-based nanoparticle.

Effective therapeutic strategies to precisely eradicate primary tumors with minimal side effects on normal tissue, inhibit metastases, and prevent tumor relapses, are the ultimate goals in the battle against cancer. We report a novel therapeutic strategy that combines adjuvant black phosphorus nanoparticle-based photoacoustic (PA) therapy with checkpoint-blockade immunotherapy. With the mitochondria targeting nanoparticle, PA therapy can achieve localized mechanical damage of mitochondria via PA cavitation and thus achieve precise eradication of the primary tumor. More importantly, PA therapy can generate tumor-associated antigens via the presence of the R848-containing nanoparticles as an adjuvant to promote strong antitumor immune responses. When combined with the checkpoint-blockade using anti-cytotoxic T-lymphocyte antigen-4, the generated immunological responses will further promote the infiltrating CD8 and CD4 T-cells to increase the CD8/Foxp3 T-cell ratio to inhibit the growth of distant tumors beyond the direct impact range of the PA therapy. Furthermore, the number of memory T cells detected in the spleen is increased, and these cells inhibit tumor recurrence. This proposed strategy offers precise eradication of the primary tumor and can induce long-term tumor-specific immunity. Electronic Supplementary Material: Supplementary material is available for this article at 10.1007/s12274-020-3028-x and is accessible for authorized users.

A stimulated liquid-gas phase transition nanoprobe dedicated to enhance the microwave thermoacoustic imaging contrast of breast tumors.

Microwave-induced thermoacoustic imaging (MTAI), combining the advantages of the high contrast of microwave imaging and the high resolution of ultrasonic imaging, is a potential candidate for breast tumor detection. MTAI probes have been used to extend thermoacoustic imaging to molecular imaging. However, due to the high content of water molecules in tissues, the thermoelastic expansion-based probes used in conventional MTAI are not capable of adequate enhancement. Herein, an MTAI nanoprobe for amplification of thermoacoustic (TA) signals by the stimulated liquid-gas phase transition mechanism has been developed, providing significantly higher signal amplitude than that from the conventional mechanism of thermoelastic expansion. The nanoprobe consists of liquid perfluorohexane (PFH) and tungsten disulfide (WS2) nanoparticles rich in defect electric dipoles. When irradiated with pulsed microwaves, the defect electric dipoles in WS2 were repeatedly polarized by gigahertz. This results in localized transient heating and an acoustic shockwave, which destroys the van der Waals forces between PFH molecules. Ultimately, liquid PFH droplets undergo a liquid-gas phase transition, generating dramatically enhanced TA signals. The practical feasibility was tested in vitro and in a breast tumor animal model. The results show that the proposed nanoprobe can greatly improve the contrast of tumor imaging. It will be a new generation probe for MTAI.