image: (A) Schematic diagram of MPP@IKE-aPD-1/diABZI preparation. (B) Particle size of nanomedicine. (C) TEM images of MPP@IKE-aPD-1/diABZI nanomedicine incubated in different environments. Scale bar, 50 nm. (D) Cumulative release of diABZI-C2-NH2 comes from pH 7.4 and pH 6.5. (E) Accumulated release of aPD-1 in pH 7.4, pH 6.5, and pH 6.5 + 10 mM GSH environments.
Credit: Hang Huang, Wenzhou Medical University.
Metastatic urothelial carcinoma has a poor prognosis: ~50% of muscle-invasive bladder cancer progresses to metastasis, and the 5-year survival for advanced/metastatic disease is <10%. Platinum-based chemotherapy was historically first-line, but its benefit is limited by renal insufficiency/poor tolerance and the lack of effective options after resistance. Immune checkpoint inhibitors have improved outcomes in a subset of patients and are supported by high tumor mutational burden and PD-L1 expression in bladder cancer; however, response rates remain only ~20%–30% and robust predictive biomarkers are lacking. “Against this backdrop—where efficacy depends not only on combination strategies but also on effective delivery.” said the author Hang Huang, a researcher at Wenzhou Medical University, “we developped a mannose-modified, pH/GSH dual-responsive nano-delivery system (MPP@IKE-aPD-1/diABZI) to enable tumor-microenvironment–specific release and lymph-node–targeted delivery for metastatic bladder cancer therapy.”
The nano-delivery system was prepared via a three-step workflow. First, Mannose-PEG-ss-PCL and the pH-sensitive CDM-PEG-PCL were dissolved in acetone and slowly added into PBS (pH 7.4) under stirring to drive self-assembly into MPP nanoparticles, followed by solvent evaporation and centrifugation to collect the particles. Second, diABZI and IKE were pre-dissolved in DMSO, mixed with the MPP dispersion, and stirred at room temperature to achieve co-loading; free drugs were removed by dialysis to yield MPP@diABZI/IKE. Third, aPD-1 was thiolated using Traut’s reagent and purified, then reacted with maleimide-functionalized drug-loaded nanoparticles in PBS to conjugate the antibody; unconjugated antibodies were removed by size-exclusion chromatography, producing the final formulation MPP@IKE-aPD-1/diABZI.
The nano-system (MPP@IKE-aPD-1/diABZI) exhibited a well-controlled size distribution and structural integrity during stepwise assembly: blank MPP was ~73.6 nm (PDI=0.12), increased to ~82.4 nm after IKE loading, and reached ~94.2 nm in the final formulation (PDI=0.18). The zeta potential shifted from −15.3 mV at pH 7.4 to −3.2 mV at pH 6.5, indicating an acidity-triggered charge reversal that can facilitate cellular uptake. TEM confirmed spherical morphology under physiological conditions, swelling under acidic pH, and disintegration in simulated TME (pH 6.5 + 10 mM GSH) due to disulfide cleavage—supporting low leakage in circulation and on-site release in tumors. Consistently, 24-h cumulative release reached ~73.3% for diABZI at pH 6.5 (vs <20% at pH 7.4), and ~83.4% for aPD-1 at pH 6.5+GSH (vs ~8.4% under neutral conditions). In uptake assays, exposure to pH 6.5 + 10 mM GSH yielded ~94.52% cellular uptake at 4 h, markedly higher than pH 7.4 + 0 mM GSH (~24.22%).
In vivo, the combination formulation produced robust tumor control with a reported tumor inhibition rate of 94.5%. Survival benefit was substantial (median survival 35 d vs 18 d in PBS; 80% survival at 60 d vs 0% in PBS). Mechanistically, treatment remodeled the immune microenvironment: mature DCs (CD80+CD86+) increased to 42.4% (vs 6.2% in PBS), CD8+ T-cell infiltration rose to 156 cells/mm2 (vs 12 cells/mm2), and effector readouts (GZMB, IFN-γ) were elevated. In a resection–rechallenge setting, durable immune memory was evidenced by elevated Tcm (~38.7%) and Tem (~51.2%). Importantly, in a spontaneous metastasis model, lung metastatic nodules were reduced by 92% (2.3 vs 28.5), accompanied by dense CD8+ T-cell infiltration and DC–CD8 spatial coordination within metastatic lesions.
In summary, this work not only provides a theoretical basis for overcoming immunotherapy resistance but also establishes a technical foundation for developing combination immunotherapies based on microenvironment regulation. The mannose-modified nanodelivery system is significantly superior to single ICI or ferroptosis inducer therapy through precise targeting, multimodal therapy, and TME remodeling to achieve stronger inhibition of tumor growth and metastasis. However, this study also has some limitations. Systemic toxicity and long-term effects warrant systematic evaluation; oxidative stress–sensitive nanoparticles may engage complement bypass pathways; and in perfusion settings, potential entry into the bloodstream via bladder mucosa raises concerns about systemic exposure. “In our future work, we will further validate the targeting mechanisms at the cellular/tissue level (such as MR expression detection, fluorescence co-localization, lymph node section confocal imaging, etc.) and evaluate long-term efficacy and safety in models closer to clinical practice, to support the feasibility demonstration for clinical translation.” said Hang Huang.
Authors of the paper include Hang Huang, Fangdie Ye, Tianyue Liu, Junkai Hong, Haoran Jiang, Zijian Chen, Qimeng Li, and Wei Chen.
This work was supported by “Pioneer” and “Leading Goose” R&D Program of Zhejiang (2025C02072), Zhejiang Province Medical and Health Science and Technology Project (2024KY141), East Clinical Center of Oncology (no. ECCO-KY-24003-2), Beijing Life Oasis Public Service Center (BH004506), Wenzhou Science and Technology Project (Y20220186), Discipline Cluster of Oncology Wenzhou Medical University China (no. z1-2023003), Clinical and Basic Research Project of Beijing Kangmeng Charity Foundation Medical Research and Development Fund (CB23005), and Zhejiang Provincial Traditional Chinese Medicine Scientific Research Fund (2022ZB215).
The paper, “Nano-Immunotherapy Synergizing Ferroptosis and STING Activation in Metastatic Bladder Cancer” was published in the journal Cyborg and Bionic Systems on Jan. 9, 2026, at DOI: 10.34133/cbsystems.0458.
Journal
Cyborg and Bionic Systems