Acidic extracellular pH (pHe), a hallmark of the solid tumor microenvironment, is closely associated with increased tumor malignancy and therapy resistance. However, the real-time, noninvasive visualization of dynamic pHe changes in vivo remains a formidable technical challenge. In this study, we developed a novel small-molecule ratiometric near-infrared fluorescent probe PSMA-ratio-pH targeting the prostate-specific membrane antigen (PSMA), designed to enable rapid and precise imaging of prostate cancer acidity in living mice. This probe exhibits a pKa of 6.4, a value well-suitable for tumor acidity detection, along with dual near-infrared emission, high sensitivity (1250-fold activation), good reversibility, concentration-independent response, robust photostability, and high selectivity. Cellular experiments confirmed its specific anchoring to PSMA on the cell membrane and reliable sensing of pHe. In mouse models of prostate cancer, the probe achieved rapid tumor targeting and ratiometric acidity imaging within 15 min post intravenous injection owing to favorable pharmacokinetics and high PSMA affinity, and was capable of monitoring dynamic pH changes in tumor acidosis. This research provides a powerful molecular tool for the real-time and precise visualization of tumor microenvironment acidity, holding broad application prospects in cancer diagnosis and treatment evaluation.

Rationale:Prostate cancer remains a leading cause of cancer-related mortality in men. Although PSMA-directed theranostics have achieved clinical success, heterogeneous expression and therapy-induced downregulation limit their broad applicability. B7-H3 (CD276), which is highly and stably expressed in prostate cancer, represents a promising alternative theranostic target. Methods:A B7-H3 targeted antibody-drug conjugate (ADC) was radiolabeled with [89Zr]Zr- for immunoPET imaging and [177Lu]Lu for radionuclide therapy. In vitro binding specificity, in vivo tumor targeting, biodistribution, therapeutic efficacy, dosimetry, and safety were systematically assessed in prostate cancer xenograft models, with comparisons to radiolabeled antibody, ADC monotherapy, sequential therapy, and vehicle controls. Results:Histological analysis in prostate cancer patients suggested B7-H3 was consistently and highly expressed in primary and metastatic lesions and remained stable under therapeutic intervention. [89Zr]Zr-B7-H3 ADC immunoPET imaging demonstrated high and specific tumor uptake (33.2 ± 1.0 %ID/g at 144 h) and favorable tumor-to-background ratios. Therapeutic studies revealed that [177Lu]Lu-B7-H3 ADC achieved marked tumor growth inhibition and survival benefit, with comparable efficacy even if reduced the dose of ADC in the treatment system. Integrated [177Lu]Lu-ADC therapy outperformed radiolabeled antibody, ADC monotherapy, and sequential treatment strategies. No additional organ toxicity was observed compared with ADC alone, and transient hematological changes following [177Lu]Lu administration were reversible. Conclusions:The [89Zr]Zr-/[177Lu]Lu-B7-H3 ADC theranostic platform enables accurate imaging, precise tumor targeting, and enhanced antitumor efficacy at reduced ADC doses without increasing systemic toxicity, supporting its translational potential for prostate cancer.

BACKGROUND:B cell maturation antigen (BCMA) is a key therapeutic target in multiple myeloma (MM), yet its whole-body in vivo distribution and role in disease assessment remain incompletely defined. We aimed to evaluate the safety, diagnostic performance, and clinical utility of a novel BCMA-targeted PET tracer, 68Ga-PFBC01, in patients with plasma cell disorders. METHODS:We conducted a single-center, prospective, single-arm phase I trial (ClinicalTrials.gov NCT06717113). Fifty patients underwent 68Ga-PFBC01 PET/CT, including 40 with paired 18F-FDG PET/CT for head-to-head comparison. Primary outcomes included diagnostic performance (sensitivity, specificity, PPV, NPV, and inter-reader agreement). Secondary outcomes included correlations with clinical biomarkers, treatment response assessment, impact on clinical decision-making, and safety. RESULTS:68Ga-PFBC01 PET/CT demonstrated superior diagnostic performance compared with 18F-FDG PET/CT (sensitivity 96.9% vs 84.6%; specificity 71.4% vs 60.0%). Quantitative PET-derived tumor burden correlated with M protein (R = 0.325, P = 0.026), free light chains (R = 0.340-0.437, P ≤ 0.015), soluble BCMA (R = 0.433, P = 0.050), and bone marrow plasma cells (R = 0.682, P < 0.001). Imaging findings altered clinical management in multiple cases, enabling both therapy escalation and de-escalation. Blood-pool uptake strongly correlated with soluble BCMA (R = 0.899, P < 0.001) and overall disease burden (R = 0.736, P < 0.001). No serious tracer-related adverse events were observed; two patients (4%) experienced mild events. CONCLUSION:68Ga-PFBC01 PET/CT provides biologically specific, whole-body assessment of MM, outperforming 18F-FDG and enabling integrated evaluation of tumor burden and systemic disease activity, with direct implications for clinical decision-making. TRIAL REGISTRATION: CLINICALTRIALS:gov NCT06717113. FUNDING:National Natural Science Foundation of China (82472018, 82402320) to Prof. Lei Kang, 82402320 to Dr. Tianyao Wang); Beijing Nova Program (20240484725) to Prof. Lei Kang; National High Level Hospital Clinical Research Funding (Interdisciplinary Research Project of Peking University First Hospital, 2024IR07, Scientific and Technological Achievements Transformation Incubation Guidance Fund Project of Peking University First Hospital, 2025CX38, 2024CX18) to Prof. Lei Kang.

Magnetic resonance imaging (MRI) and nuclear medicine imaging are widely used for cancer detection due to their high soft tissue resolution and sensitivity. Each modality has inherent limitations; therefore, integrated techniques such as positron emission tomography/magnetic resonance (PET/MR) have been developed. However, achieving simultaneous signal enhancement for both PET and MRI in clinical settings remains challenging. In this study, we employed gallium-68 (68Ga)-labelled NaGdF4@RGD nanoprobes as a model system to establish a synchronous PET/MR imaging strategy for tumor diagnosis. These nanoprobes exhibited suitable radiochemical half-life, and effective tumor-associated targeting, enabling successful PET/MR imaging across multiple tumor models, including hepatoma, renal cancer, and breast cancer in vivo. Notably, this imaging strategy allowed time-resolved visualization of nanoprobe distribution and prolonged retention behavior in orthotopic liver tumors during delayed imaging periods, providing imaging-based insights into nanomedicine pharmacodynamics.

Abstract Objective This study aims to investigate the expression profiling characteristics of N6-methyladenosine (m6A) RNA modification regulators in sepsis, their associations with glycolytic metabolic reprogramming, and their preliminary prognostic value. Methods We integrated multiple sepsis transcriptomic cohorts (GSE65682, GSE95233, GSE54514) from the GEO database to systematically analyze the differential expression of 15 m6A regulators. Gene Set Variation Analysis (GSVA) scores, weighted gene co-expression network analysis (WGCNA) networks, and Spearman correlation analyses were utilized to assess the associations between m6A regulators and glycolytic activity. The regulation of glycolytic genes by m6A modifications was confirmed using ALKBH5 knockout models (GSE198316, GSE224650) and MeRIP-seq data (GSE225143). A prognostic model was developed by integrating CIBERSORT immune cell infiltration analysis, single-cell RNA sequencing data (GSE147363), and LASSO-Cox regression. Results Most m6A regulators are significantly downregulated in patients with sepsis, while IGF2BP2 and IGF2BP3 are upregulated. ALKBH5 clusters with IGF2BP2 within the same WGCNA module and exhibits a positive correlation with glycolytic activity (rho=0.592, P =1.0 × 10⁻ 29 ). The differentially expressed genes (DEGs) resulting from ALKBH5 knockout significantly overlap with sepsis-associated DEGs ( n =124; OR=2.48, P =5.10 × 10⁻ 11 ), which are enriched in the HIF-1 signaling pathway and glycolytic processes. Independent validation confirmed a directional consistency of 89.6%. MeRIP-seq data indicated m6A-mediated associations with glycolytic genes, including ENO1, GAPDH, HK2, and LDHA. Single-cell analysis demonstrated a positive correlation between ALKBH5 and most glycolytic genes in CD14+ monocytes. A prognostic model based on four m6A genes (HNRNPC, YTHDF1, YTHDF2, VIRMA) achieved a C-index of 0.750 in the training set and 0.709–0.718 in external validation sets. Conclusion These integrated analyses suggest that ALKBH5-associated m6A modification is correlated with sepsis-associated glycolytic reprogramming and support a biologically plausible, hypothesis-generating ALKBH5-associated glycolytic program that requires prospective and experimental validation. The m6A-based four-gene model showed preliminary prognostic potential for 28-day mortality, but its external reproducibility was incomplete and requires validation in larger, prospectively collected and clinically harmonized cohorts.

ABSTRACT Fast click reactions that operate efficiently in aqueous buffers are highly desirable across many areas of chemistry, yet remain scarce. Herein, we report an u ltrafast 4‐ a zido p yridinium‐based S taudinger (UApS) ligation that proceeds with large bimolecular reaction rate constants (10 3 –10 4 M −1 s −1 ) under catalyst‐free, physiologically relevant conditions. We introduced a new class of substituted 4‐azido‐1‐alkylpyridinium reagents that are both water‐stable and exceptionally reactive toward triarylphosphines, yielding phosphazide adducts that release nitrogen gas and convert into iminophosphoranes. These products were structurally validated by single‐crystal x‐ray diffraction studies and possess good aqueous stability. Mechanistic and computational investigations elucidated the UApS ligation pathway and its fast kinetics arising from the substituted 4‐azidopyridinium scaffolds. We demonstrate that the UApS ligation enables efficient protein labeling and cell‐surface imaging at low reagent concentrations. In combination with the established tetrazine ligation, we demonstrate that the UApS ligation facilitates dual labeling of distinct cellular compartments in living cells. Moreover, the UApS ligation is suitable for live‐cell stimulated emission depletion (STED) super‐resolution imaging of filopodia. Overall, the UApS ligation should extend fast click chemical space, providing a new addition to the bioconjugation toolkit.

Alkali burns pose a significant risk of corneal injury, leading to potential blindness. During the progression of alkali burns, heightened oxidation levels can induce corneal damage, resulting in diminished clarity and vision loss. In this study, we chose metallic iron in conjunction with a small molecule, curcumin, to synthesize a curcumin-iron coordinated nanocomposite aimed at enhancing the bioaccessibility and targeting capabilities of curcumin. It could be found that Fe-curcumin coordination polymer nanodots (Fe-Cur CPNs) were comparably effective in suppressing corneal neovascularization, and they exhibited notable advantages in promoting corneal epithelial repair with minimal adverse effects. Additionally, Fe-Cur CPNs inhibited the activation of the nuclear factor-κ-gene binding (NF-κB) signaling pathway by scavenging reactive oxygen species (ROS), thus mitigating corneal neovascularization, which might represent a potential mechanism underlying the therapeutic effect of the Fe-Cur CPNs in alkali burn treatment. Moreover, treatment with the Fe-Cur CPNs did not result in any signs of cytotoxicity, hematological toxicity, or internal organ damage, further confirming the safety profile of this therapeutic agent. In conclusion, Fe-Cur CPNs present a novel, safe, and efficacious approach for addressing corneal alkali burns.

The Trop2-targeting antibody-drug conjugate (ADC) sacituzumab govitecan (Trodelvy) has demonstrated remarkable efficacy in patients with metastatic triple-negative breast cancer (TNBC). ImmunoPET imaging offers a noninvasive method to visualize the expression and distribution of target antigens in vivo. In this study, we developed F(ab’)2 fragments of Trodelvy for immunoPET imaging to detect Trop2 expression in TNBC models, aiming to achieve a shorter imaging window. Trodelvy-F(ab’)2 was prepared using the IdeS protease kit and purified with Magne Protein A beads and MagneHis™ Ni Particles. The products were characterized by non-reducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis and high-performance liquid chromatography. Trodelvy-F(ab’)2 was subsequently conjugated with p-SCN-Bn-NOTA (NOTA) for radiolabeling with 64Cu. ImmunoPET imaging using [64Cu]Cu-NOTA-Trodelvy-F(ab’)2 was conducted at multiple time points to assess its in vivo targeting capability. Immunohistochemical and immunofluorescence analyses were performed on tumor tissues obtained from tumor-bearing mice. The radiochemical yield of [64Cu]Cu-NOTA-Trodelvy-F(ab’)2 exceeded 90

Gastrointestinal (GI) malignancies remain to be one of the most prevalent malignancies that are often characterized by a dismal prognosis. Nanoplatforms present a groundbreaking avenue for enhancing targeting strategies and multifunctionality in cancer treatment. The emergence of nanotechnology, particularly the innovation of smart responsive nanomaterials, has revolutionized cancer diagnosis and therapy. This review begins by exploring the design principles of smart responsive nanomaterials, focusing on the various exogenous and endogenous stimuli that drive their functionality. Furthermore, we provide a comprehensive summary of the applications of smart responsive nanomaterials in the treatment of GI malignancies over the past five years. Our aim is to contribute to the growing body of knowledge on smart responsive nanomaterials in GI malignancies, spark innovative ideas, and encourage further advancements in this field. Finally, we discuss the prospects and challenges associated with the use of smart responsive nanomaterials in GI malignancies.

Triple-negative breast cancer (TNBC) and non-small cell lung cancer (NSCLC) are aggressive solid tumors with limited treatment options. Nectin cell adhesion molecule 4 (Nectin4) is a tumor-associated antigen frequently overexpressed in these cancers, making it a promising therapeutic and imaging target. Here, we report the development and evaluation of [89Zr]Zr-desferrioxamine (DFO)-Padcev, a radiolabeled antibody-drug conjugate targeting Nectin4, for immuno-positron emission tomography (ImmunoPET) imaging. [89Zr]Zr-DFO-Padcev is synthesized with a radiochemical yield of 88.87% ± 2.59% and a radiochemical purity above 99%. ImmunoPET imaging successfully visualizes Nectin4-positive tumors in TNBC (MDA-MB-468) and NSCLC (H1975) models as early as 6 h post-injection, with uptake progressively increasing and peaking at 48 h (14.57 ± 1.94 and 9.50 ± 0.76 %ID/g, respectively). Minimal tumor uptake is observed in blocking and Nectin4-negative controls, confirming specificity. Complementary fluorescence imaging further reveals the in vivo distribution of Padcev, providing valuable insights into optimal therapeutic time windows.

Purpose:ImmunoPET imaging of PD-L1 has emerged as a promising strategy for patient stratification and treatment response monitoring in immunotherapy. This study aimed to evaluate [89Zr]Zr-DFO-Durvalumab in noninvasive imaging of PD-L1 expression in non-small cell lung cancer (NSCLC) and bladder cancer. Materials and methods:Durvalumab was conjugated with p-SCN-Bn-DFO and labeled with [89Zr]Zr-oxalate, achieving high radiochemical purity (> 99 %) and stability. PD-L1 expression in human NSCLC (H1975, A549) and bladder cancer (HT1376, T24) cell lines was characterized via flow cytometry and immunofluorescence. In vitro binding and uptake studies were conducted to assess specificity. ImmunoPET imaging and biodistribution analyses were performed in mouse xenograft models. Additionally, fluorescence-guided imaging using IRDye 800CW-labeled Durvalumab was evaluated. Results:H1975 and HT1376 cells exhibited strong PD-L1 expression and high tracer uptake, while A549 and T24 cells were low in PD-L1 expression. In vivo PET imaging revealed significantly higher uptake in PD-L1-positive tumors. At 48 h p.i., the accumulation in H1975 tumor was 10.73 ± 1.89 %ID/g, compared to 4.47 ± 0.55 %ID/g in A549 tumor (P = 0.0219) and 4.60 ± 0.46 %ID/g in blocking control (P = 0.0228). HT1376 tumor reached 10.63 ± 1.35 %ID/g, significantly higher than T24 (4.10 ± 0.89 %ID/g, P = 0.0037), blocking (4.10 ± 0.92 %ID/g, P = 0.0036), and [89Zr]Zr-DFO-IgG control (5.67 ± 0.90 %ID/g, P = 0.0089). Tumor-to-muscle ratios at 48 h for H1975 and HT1376 tumors were 14.30 ± 2.02 and 15.00 ± 1.62, respectively, indicating excellent contrast. Fluorescence imaging with IRDye 800CW-Durvalumab further confirmed the uptake in PD-L1-specific tumors. No significant histological abnormalities were observed in major organs. The estimated human effective dose was 0.0522 mSv/MBq. Conclusion:[89Zr]Zr-DFO-Durvalumab enables specific, high-contrast ImmunoPET and fluorescence imaging of PD-L1-expressing NSCLC and bladder cancers. This dual-modality imaging platform holds potential for noninvasive assessment of PD-L1 status and personalized immunotherapy planning.

Pancreatic ductal adenocarcinoma (PDAC) is the most prevalent form of pancreatic cancer, with high malignancy and poor prognosis. The cellular mesenchymal-epithelial transition factor (c-Met) is overexpressed in 84

Nectin4 is a tumor-associated antigen that is highly expressed in various solid tumors and is associated with tumor progression and poor prognosis. We performed an ImmunoPET imaging study to assess Nectin4 expression in gastric and bladder cancer models utilizing [64Cu]Cu-NOTA-Padcev. ImmunoPET imaging confirmed significant tumor uptake at 48 h in NCI-N87 (13.83 ± 1.80% ID/g) and HT-1376 (22.97 ± 2.67% ID/g) models, which was significantly higher than in HGC-27 (5.93 ± 0.15% ID/g, P = 0.0163) and UM-UC-3 (5.40 ± 0.69% ID/g, P = 0.0051) models. Co-injection of [64Cu]Cu-NOTA-Padcev with 2 mg of unlabeled Padcev significantly decreased tumor uptake in NCI-N87 (5.53 ± 0.59% ID/g, P = 0.0097) and HT-1376 (4.97 ± 0.68% ID/g, P = 0.0049), indicating receptor-specific binding. Fluorescence imaging consistently showed significantly greater tumor accumulation in the IRDye 800CW-Padcev group than in the blocking group for both the NCI-N87 model (64.05 ± 8.97 × 107 vs 10.12 ± 1.83 × 107 at 168 h for the NCI-N87 model, P = 0.0072) and the HT-1376 model (99.48 ± 13.61 × 107 vs 10.12 ± 1.83 × 107 at 168 h for the HT-1376 model, P = 0.0068). [64Cu]Cu-NOTA-Padcev ImmunoPET imaging demonstrated specific, rapid, and prolonged accumulation in Nectin4-high tumors in both gastric and bladder cancer models.

Trop2 exhibits significantly elevated expression in numerous solid malignancies, playing a crucial role in tumor advancement, whereas its presence in healthy tissues is minimal. In this study, we investigated Trop2 expression in bladder cancer models using [64Cu]Cu-NOTA-Trodelvy for immunoPET imaging. In HT-1376 models, [64Cu]Cu-NOTA-Trodelvy effectively visualized tumor as early as 12 h p.i. (10.30 ± 1.45% ID/g), with tumor uptake increasing and peaking at 48 h p.i. (13.73 ± 1.16% ID/g), highlighting its potential for tumor imaging. Control groups also demonstrated low tumor uptake (5.27 ± 1.14% ID/g at 48 h in the blocking group; 6.33 ± 0.74% ID/g at 48 h in UM-UC-3; 4.50 ± 0.30% ID/g at 48 h in the [64Cu]Cu-NOTA-IgG group). Long-term fluorescence imaging further confirmed the tumor uptake rate in the IRDye 800CW-Trodelvy group was significantly higher than in the IRDye 800CW-Trodelvy blockade group (P < 0.001). Our findings demonstrated that [64Cu]Cu-NOTA-Trodelvy enables specific and prolonged tumor accumulation in bladder cancer models, providing precise and noninvasive monitoring of Trop2 expression.

PURPOSE:The Trop2-targeting antibody-drug conjugate (ADC), sacituzumab govitecan (TrodelvyTM), demonstrates significant therapeutic efficacy in targeting Trop2-expressing tumors. In this study, we utilized immunoPET imaging to assess Trop2 expression in bladder cancer models using [89Zr]Zr-DFO-Trodelvy. MATERIALS AND METHODS:Trop2 expression levels in bladder cancer cell lines were measured using flow cytometry and immunofluorescence staining. Radiolabeling of DFO-Trodelvy with 89Zr was carried out in Na2CO3 buffer at pH 7 (37°C, 1.5 h). ImmunoPET imaging with [89Zr]Zr-DFO-Trodelvy was performed at multiple time points to evaluate in vivo targeting. Additionally, tumor tissues from tumor-bearing mice were analyzed by immunofluorescence. RESULTS:The radiochemical yield of [89Zr]Zr-DFO-Trodelvy was >90%, with radiochemical purity exceeding 99%. Trop2 expression was high in HT1376 cells and low in T24 cells. ImmunoPET imaging demonstrated effective visualization of tumors in HT1376 models as early as 6 h post-injection, with tumor uptake reaching peak at 48 h (16.33 ± 0.90 %ID/g), followed by a gradual decline. In contrast, T24 tumors showed significantly lower uptake (6.20 ± 0.99 %ID/g, P = 0.0005). Co-injection with 2 mg of unlabeled Trodelvy significantly reduced tumor uptake in HT1376 models (4.50 ± 0.51 %ID/g, P = 0.0004), confirming target specificity. At 48 h, a high tumor-to-background ratio was observed, indicating selective accumulation in tumor tissue. CONCLUSIONS:[89Zr]Zr-DFO-Trodelvy enables precise immunoPET imaging of bladder cancer models with high Trop2 expression, demonstrating specific and sustained tumor accumulation. These findings highlight the potential of this imaging approach for the noninvasive assessment of Trop2 expression.

This study aimed to develop and evaluate [64Cu]Cu-NOTA-EV-F(ab’)2 as a rapid and specific immunoPET imaging probe targeting Nectin-4 in gastric cancer (GC) and non-small cell lung cancer (NSCLC). F(ab’)2 fragments were generated from enfortumab vedotin (EV) using IdeS protease and conjugated with p-SCN-Bn-NOTA for radiolabeling with 64CuCl2. The radiochemical yield was 85.40 ± 2.43

Nectin cell adhesion molecule 4 (Nectin4), a Ca 2+ ‐independent immunoglobulin‐like cell adhesion molecule, plays a role in both physiological and pathological processes. Nectin4 is physiologically expressed at minimal levels in most normal adult tissues; however, it is significantly upregulated in various solid tumors. It can drive cell proliferation, metastasis, angiogenesis, adhesion, recurrence, and DNA mismatch repair in tumors, leading to poor prognosis. Notably, the United States Food and Drug Administration has approved enfutumab vedotin, a novel antibody–drug conjugate targeting Nectin4, for the therapy of urothelial carcinoma, highlighting the significance of Nectin4 in targeted therapy. However, accurate diagnosis and evaluation of patients is also important. Visualization of Nectin4 expression levels can be achieved with molecular imaging, including positron‐emission tomography, single‐photon emission computed tomography, and near‐infrared fluorescence imaging. Incorporating Nectin4‐targeted molecular imaging into clinical practice is vital for the diagnosis, differentiation, treatment decision, efficacy evaluation, and prognosis prediction of a broad spectrum of solid tumors. We reviewed research advances in Nectin4‐targeted molecular imaging, focusing on theranostic applications in different tumor types, including breast, urothelial, gastric, pancreatic, ovarian, colorectal, and other cancers. We also evaluated the present situation by investigating research progress, diagnostic performance, and limitations. Finally, we discuss the challenges associated with clinical implementation and present our views on advancing this area to guide future research.