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Immunotherapy can enhance primary tumor efficacy, restrict distant growth, and combat lung metastasis. Unfortunately, it remains challenging to effectively activate the immune response. Here, tertiary butyl, methoxy, and triphenylamine (TPA) were utilized as electron donors to develop multifunctional photosensitizers (PSs). CNTPA-TPA, featuring TPA as the donor (D) and cyano as the acceptor (A), excelled in reactive oxygen species (ROS) generation due to its smaller singlet-triplet energy gap (ΔES-T) and larger spin-orbit coupling constant (SOC). Additionally, cyano groups reacted with glutamate (Glu) and glutathione (GSH), reducing intracellular GSH levels. This not only enhanced PDT efficacy but also triggered redox dyshomeostasis-mediated ferroptosis. The positive effects of photodynamic therapy (PDT) and ferroptosis promoted immunogenic cell death (ICD) and immune activation. By further combining anti-programmed cell death protein ligand-1 (anti-PD-L1) antibody, the powerful treatments of ferroptosis-assisted photodynamic immunotherapy significantly eradicated the primary tumors, inhibited the growth of distant tumors, and suppressed lung metastasis. In this study, a three-pronged approach was realized by single-component CNTPA-TPA, which simultaneously served as metal-free ferroptosis inducers, type-I photosensitizers, and immunologic adjuvants for near-infrared fluorescence imaging (NIR FLI)-guided multimodal phototheranostics of tumor. STATEMENT OF SIGNIFICANCE: (1) CNTPA-TPA shared the smallest singlet-triplet energy gap and the largest spin-orbit coupling constant, which boosted intersystem crossing for efficient type-I photodynamic therapy (PDT); (2) Special reactions between cyano groups with glutamate and glutathione in mild conditions restricted the biosynthesis of intracellular GSH. GSH-depletion efficiently induced glutathione peroxidase 4 inactivation and lipid peroxide, resulting in ferroptosis of tumor cells; (3) The combination treatments of ferroptosis-assisted photodynamic immunotherapy induced by single-component CNTPA-TPA with the participation of anti-PD-L1 antibody resulted in increased T-cell infiltration and profound suppression of both primary and distant tumor growth, as well as lung metastasis.

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The metabolic signature identification of colorectal cancer is critical for its early diagnosis and therapeutic approaches that will significantly block cancer progression and improve patient survival. Here, we combined an untargeted metabolic analysis strategy based on internal extractive electrospray ionization mass spectrometry and the machine learning approach to analyze metabolites in 173 pairs of cancer samples and matched normal tissue samples to build robust metabolic signature models for diagnostic purposes. Screening and independent validation of metabolic signatures from colorectal cancers via machine learning methods (Logistic Regression_L1 for feature selection and eXtreme Gradient Boosting for classification) was performed to generate a panel of seven signatures with good diagnostic performance (the accuracy of 87.74%, sensitivity of 85.82%, and specificity of 89.66%). Moreover, seven signatures were evaluated according to their ability to distinguish between cancer and normal tissues, with the metabolic molecule PC (30:0) showing good diagnostic performance. In addition, genes associated with PC (30:0) were identified by multiomics analysis (combining metabolic data with transcriptomic data analysis) and our results showed that PC (30:0) could promote the proliferation of colorectal cancer cell SW480, revealing the correlation between genetic changes and metabolic dysregulation in cancer. Overall, our results reveal potential determinants affecting metabolite dysregulation, paving the way for a mechanistic understanding of altered tissue metabolites in colorectal cancer and design interventions for manipulating the levels of circulating metabolites.

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Sonodynamic therapy (SDT) offers a remarkable non-invasive ultrasound (US) treatment by activating sonosensitizer and generating reactive oxygen species (ROS) to inhibit tumor growth. The development of multifunctional, biocompatible, and highly effective sonosensitizers remains a current priority for SDT. Herein, the first report that Mn(II) ions chelated Gd-TCPP (GMT) nanosheets (NSs) are synthesized via a simple reflux method and encapsulated with pluronic F-127 to form novel sonosensitizers (GMTF). The GMTF NSs produce a high yield of ROS under US irradiation due to the decreased highest occupied molecular orbital-lowest unoccupied molecular orbital gap energy (2.7-1.28 eV). Moreover, Mn(II) ions endow GMTF with a fascinating Fenton-like activity to produce hydroxyl radicals in support of chemodynamic therapy (CDT). It is also effectively used in magnetic resonance imaging (MRI) with high relaxation rate (r 1: 4.401 mM-1 s-1) to track the accumulation of NSs in tumors. In vivo results indicate that the SDT and CDT in combination with programmed cell death protein 1 antibody (anti-PD-1) show effective metastasis prevention effects, and 70% of the mice in the GMTF + US + anti-PD-1 group survived for 60 days. In conclusion, this study develops a sonosensitizer with promising potential for utilizing both MRI-guided SDT and CDT strategies.

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Designing mitochondria-targeting phototheranostic agents (PTAs), which can simultaneously possess exceptional and balanced type-I photodynamic therapy (PDT) and photothermal therapy (PTT) performance, still remains challenging. Herein, benzene, furan, and thiophene were utilized as π bridges to develop multifunctional PTAs. STB with thiophene as a π bridge, in particular, benefiting from stronger donor-accepter (D-A) interactions, reduced the singlet-triplet energy gap (ΔES1-T1), allowed more free intramolecular rotation, and exhibited outstanding near-infrared (NIR) emission, effective type-I reactive oxygen species (ROS) generation, and relatively high photothermal conversion efficiency (PCE) of 51.9%. In vitro and in vivo experiments demonstrated that positive-charged STB not only can actively target the mitochondria of tumor cells but also displayed strong antitumor effects and excellent in vivo imaging ability. This work subtly established a win-win strategy by π bridge engineering, breaking the barrier of making a balance between ROS generation and photothermal conversion, boosting a dual enhancement of PDT and PTT performance, and stimulating the development of multimodal imaging-guided precise cancer phototherapy.

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Phototheranostic agents have thrived as prominent tools for tumor luminescence imaging and therapies. Herein, a series of organic photosensitizers (PSs) with donor-acceptors (D-A) are elaborately designed and synthesized. In particular, PPR-2CN exhibits stable near infrared-I (NIR-I) emission, excellent free radicals generation and phototoxicity. Experimental analysis and calculations imply that a small singlet-triplet energy gap (ΔES1-T1 ) and large spin-orbit coupling (SOC) constant boost the intersystem crossing (ISC), leading to type-I photodynamic therapy (PDT). Additionally, the specific glutamate (Glu) and glutathione (GSH) consumption abilities of PPR-2CN inhibit the intracellular biosynthesis of GSH, resulting in redox dyshomeostasis and GSH-depletion causing ferroptosis. This work first realizes that single component organic PS could be simultaneously used as a type-I photodynamic agent and metal-free ferroptosis inducer for NIR-I imaging-guided multimodal synergistic therapy.

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A C1-type d-glucose-conjugated fluorescent probe Glu-1-O-DCSN was synthesized and showed deep-red emission at 685 nm with a Stokes shift of up to 150 nm in DMSO. In in vitro live cell imaging, Glu-1-O-DCSN exhibited similar and competitive uptake behaviours to d-glucose and was selectively located in mitochondria. Furthermore, Glu-1-O-DCSN was successfully employed for in vivo hypermetabolic tumor targeting.

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To disclose the effect of architecture over fluorescence behaviors of polymers, linear and hyperbranched poly(4-(cyanomethyl)phenyl methacrylate)s (PCPMAs) were synthesized by using atom transfer radical polymerization (ATRP). Compared to linear PCPMAs with weakly AIE (AIE: aggregation-induced-emission) characteristics and small-molecule analogues of 4-(cyanomethyl)phenyl isobutyrate (CPB) with ACQ (ACQ: aggregation-caused-quenching) behaviors, hyperbranched PCPMA showed dramatically stronger fluorescence at both solution and solid states and more significant AIE characteristics, which were further enhanced by increasing the branching degree, indicating a significant hyperbranching-enhanced-emission effect (HEE). The HEE effect was attributed to the strong promotion of hyperbranched architecture over the formation of a nitrile group cluster with through-space conjugation (TSC). The HEE effect provided a promising methodology to construct efficient nontraditional fluorescent polymers without large-conjugated, rigid, and planar emitter groups.

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A facile and efficient approach for design and synthesis of organic fluorescent nanogels has been developed by using a pre-synthesized polymeric precursor. This strategy is achieved by two key steps: (i) precise synthesis of core⁻shell star-shaped block copolymers with crosslinkable AIEgen-precursor (AIEgen: aggregation induced emission luminogen) as pending groups on the inner blocks; (ii) gelation of the inner blocks by coupling the AIEgen-precursor moieties to generate AIE-active spacers, and thus, fluorescent nanogel. By using this strategy, a series of star-shaped block copolymers with benzophenone groups pending on the inner blocks were synthesized by grafting from a hexafunctional initiator through atom transfer radical copolymerization (ATRP) of 4-benzoylphenyl methacrylate (BPMA) or 2-(4-benzoylphenoxy)ethyl methacrylate (BPOEMA) with methyl methacrylate (MMA) and tert-butyldimethylsilyl-protected 2-hydroxyethyl methacrylate (ProHEMA) followed by a sequential ATRP to grow PMMA or PProHEMA. The pendent benzophenone groups were coupled by McMurry reaction to generate tetraphenylethylene (TPE) groups which served as AIE-active spacers, affording a fluorescent nanogel. The nanogel showed strong emission not only at aggregated state but also in dilute solution due to the strongly restricted inter- and intramolecular movement of TPE moiety in the crosslinked polymeric network. The nanogel has been used as a fluorescent macromolecular additive to fabricate fluorescent film.