Engineered Nanoprobes for Immune Activation Monitoring

Self-delivery nanodrug to manipulate tumor microenvironment for boosting photodynamic cancer immunotherapy

Immunotherapy has captured attention for its high clinical efficacy. However, its efficacy is limited by inadequate immune activation. Therefore, a platform to activate the immune system and amplify the host's immune response against tumors is urgently needed. Herein, a self-delivery photodynamic nanodrug (VAC@HSA) is reported as inducing immunogenic cell death (ICD), promoting the recruitment of dendritic cells (DCs), and normalizing tumor blood vessels. Firstly, verteporfin with laser assistance releases tumor-associated antigen to induce ICD, while celecoxib downregulates prostaglandin E2 and releases CCL5 to activate DC recruitment. Moreover, vasculature is normalized through axitinib, which contributes to reducing tumor hypoxia and reversing the immunosuppressive effects of vascular endothelial growth factor. This joint action promotes the infiltration of immune effector cells into the tumor. Therefore, the amplified photodynamic nanodrug with excellent biocompatibility effectively inhibits tumor growth and lung metastasis and produces a cascade of immune responses. Our study demonstrates a practically innovative strategy for activating cancer immunotherapy, which can alter the "cold" properties of tumors.

Semiconducting polymer dots for multifunctional integrated nanomedicine carriers

The expansion applications of semiconducting polymer dots (Pdots) among optical nanomaterial field have long posed a challenge for researchers, promoting their intelligent application in multifunctional nano-imaging systems and integrated nanomedicine carriers for diagnosis and treatment. Despite notable progress, several inadequacies still persist in the field of Pdots, including the development of simplified near-infrared (NIR) optical nanoprobes, elucidation of their inherent biological behavior, and integration of information processing and nanotechnology into biomedical applications. This review aims to comprehensively elucidate the current status of Pdots as a classical nanophotonic material by discussing its advantages and limitations in terms of biocompatibility, adaptability to microenvironments in vivo, etc. Multifunctional integration and surface chemistry play crucial roles in realizing the intelligent application of Pdots. Information visualization based on their optical and physicochemical properties is pivotal for achieving detection, sensing, and labeling probes. Therefore, we have refined the underlying mechanisms and constructed multiple comprehensive original mechanism summaries to establish a benchmark. Additionally, we have explored the cross-linking interactions between Pdots and nanomedicine, potential yet complete biological metabolic pathways, future research directions, and innovative solutions for integrating diagnosis and treatment strategies. This review presents the possible expectations and valuable insights for advancing Pdots, specifically from chemical, medical, and photophysical practitioners' standpoints.

Tumor Microenvironment-Responsive Nanoparticles Amplifying STING Signaling Pathway for Cancer Immunotherapy

Insufficient activation of the stimulator of interferon genes (STING) signaling pathway and profoundly immunosuppressive microenvironment largely limits the effect of cancer immunotherapy. Herein, tumor microenvironment (TME)-responsive nanoparticles (PMM NPs) are exploited that simultaneously harness STING and Toll-like receptor 4 (TLR4) to augment STING activation via TLR4-mediated nuclear factor-kappa B signaling pathway stimulation, leading to the increased secretion of type I interferons (i.e., 4.0-fold enhancement of IFN-β) and pro-inflammatory cytokines to promote a specific T cell immune response. Moreover, PMM NPs relieve the immunosuppression of the TME by decreasing the percentage of regulatory T cells, and polarizing M2 macrophages to the M1 type, thus creating an immune-supportive TME to unleash a cascade adaptive immune response. Combined with an anti-PD-1 antibody, synergistic efficacy is achieved in both inflamed colorectal cancer and noninflamed metastatic breast tumor models. Moreover, rechallenging tumor-free animals with homotypic cells induced complete tumor rejection, indicating the generation of systemic antitumor memory. These TME-responsive nanoparticles may open a new avenue to achieve the spatiotemporal orchestration of STING activation, providing a promising clinical candidate for next-generation cancer immunotherapy.

Photoactivatable Aptamer-CRISPR Nanodevice Enables Precise Profiling of Interferon-Gamma Release in Humanized Mice

Real-time dynamic imaging of immunoactivation-related cytokines is crucial for evaluating the efficacy of immune checkpoint blockade therapy and optimizing the treatment regimen. We introduce herein a spatiotemporally controlled nanodevice that allows in situ photoactivated imaging of interferon-gamma (IFN-γ) secretion from T cells in vitro and in vivo. The nanodevice is constructed by rational engineering of an aptamer-embedded, UV-cleavable PC-DNA probe and further integration with upconversion nanoparticles- and CRISPR-Cas12a-enhanced fluorescence systems. Using human peripheral blood mononuclear cells (PBMC)-engrafted mouse models, this nanodevice allows for the quantitative imaging of endogenous IFN-γ and its intratumoral dynamics responding to antiprogrammed cell death receptor 1 (anti-PD-1) therapy. This study thus provides a toolbox for boosting the sensitivity and precision of cytokine imaging during immune checkpoint blockade therapy, enlightening research toward imaging-guided tumor therapy.

Manganese-Enriched Zinc Peroxide Functional Nanoparticles for Potentiating Cancer Immunotherapy

Immunotherapies have shown high clinical success, however, the therapeutical efficacy is largely restrained by insufficient immune activation and an immunosuppressive microenvironment. Herein, we report tumor microenvironment (TME)-responsive manganese-enriched zinc peroxide nanoparticles (MONPs) for synergistic cancer immunotherapy by inducing the immunogenic death (ICD) of cancer cells and activating the stimulator of the interferon gene (STING) pathway. MONPs especially disassociate upon exposure to acidic tumor tissue and in situ generate •OH for the ICD effect. Moreover, Mn2+ activated the STING and synergistically induced the secretion of type I interferon and inflammatory cytokines for specific T cell responses. Meanwhile, MONPs relieved the immunosuppression of TME through decreasing Tregs and polarizing M2 macrophages to the M1 type to unleash a cascade adaptive immune response. In combination with the anti-PD-1 antibody, MONPs showed superior efficacy in inhibiting tumor growth and preventing lung metastasis. Our study demonstrates the feasibility of functional nanoparticles to amplify STING innate stimulation, showing a prominent strategy for cancer immunotherapy.

Monitoring the Cascade of Tumor-specific Immune Response in vivo via Chemoenzymatic Proximity Labeling

Monitoring the highly dynamic and complex immune response remains a great challenge owing to the lack of reliable and specific approaches. Here, we develop a strategy to monitor the cascade of tumor immune response through the cooperation of pore-forming alginate gel with chemoenzymatic proximity-labeling. A macroporous gel containing tumor-associated antigens, adjuvants, and pro-inflammatory cytokines is utilized to recruit endogenous DCs and enhance their maturation in vivo. The mature DCs are then modified with GDP-fucose-fucosyltransferase (GDP-Fuc-Fuct) via the self-catalysis of fucosyltransferase (Fuct). Following the migration of the obtained Fuct-DCs to the draining lymph nodes (dLNs), the molecular recognition mediated interaction of DCs and T cells leads to the successful decoration of T cells with GDP-Fuc-azide through the Fuct catalyzed proximity-labeling. Therefore, the activated tumor-specific T cells in dLNs and tumors can be identified through bioorthogonal labeling, opening up a new avenue for studying the immune mechanism of tumors in situ.