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Abstract Prostate cancer (PCa) is a frustrating immunogenic “cold” tumor and generally receives unsatisfied immunotherapy outcomes in the clinic. Pyroptosis is an excellent immunogenic cell death form that can effectively activate the antitumor immune response, promote cytotoxic T‐lymphocyte infiltration, and convert tumors from “cold” to “hot.” However, the in vivo application of pyroptosis drugs is seriously limited, and the upregulation of tumor PD‐L1 caused by photo‐immunotherapy further promotes immune escape. Herein, a new nano‐photosensitizer (YBS‐BMS NPs‐RKC) with pH‐response integrating immunogenic pyroptosis induction and immune checkpoint blockade is developed. The pH‐responsive polymer equipped with the cell membrane anchoring peptide RKC is used as the carrier and further encapsulated with the near‐infrared‐activated semiconductor polymer photosensitizer YBS and a PD‐1/PD‐L1 complex small molecule inhibitor BMS‐202. The pH‐driven membrane‐anchoring and pyroptosis activation of YBS‐BMS NPs‐RKC is clearly demonstrated. In vitro and in vivo studies have shown that this dual‐pronged therapy stimulates a powerful antitumor immune response to suppress primary tumor progression and evokes long‐term immune memory to inhibit tumor relapse and metastasis. This work provides an effective self‐synergistic platform for PCa immunotherapy and a new idea for developing more biocompatible photo‐controlled pyroptosis inducers.

A simple, sensitive, and fluorescent immunoassay for the detection of prostate-specific antigen (PSA) based on horseradish peroxidase and silicon dioxide nanospheres as a signal amplification strategy has been described. In the design, the primary antibody (Ab1) of PSA was first immobilized on the 96-well plates via physical adsorption between polystyrene and hydrophobic groups of the antibody molecule. The silicon dioxide nanospheres (SiO2 NSs), with large surface area and good biocompatibility, were loaded with horseradish peroxidase (HRP) and horseradish peroxidase-labeled secondary antibodies (HRP-Ab2) as signal amplification systems. In the presence of PSA, a sandwich-type immunocomplex composed of Ab1-Ag-HRP-Ab2 had been formed. Fluorescence technology was employed to obtain the response signal of the immunoassay in the L-tyrosine and H2O2 systems. Experiment results showed that a strong and stable fluorescent signal at 416 nm (excitation wavelength: 325 nm) was observed, and the changes in fluorescent intensity were related to the levels of PSA. Under the optimal conditions, the relative fluorescence intensity was linear with the logarithm of PSA concentration from 0.03 to 100 ng·mL−1, with a detection limit of 0.01 ng·mL−1 (at a signal/noise ratio of 3). In contrast to other fluorescent immunoassays, the sandwich-type immunoreaction based on the high binding ELISA plates has the advantages of being simple, stable, and easy to operate, high selectivity, small sample quantity, etc., which can be widely used in the selective detection of a variety of targets, from DNA to proteins and small molecules. Such fluorescent immunoassays should be feasible for the fields of molecular diagnosis and other life science fields in the future.