A Dual‐Mode Imaging Nanoparticle Probe Targeting PD‐L1 for Triple‐Negative Breast Cancer

Abstract

Chemotherapy has remained the mainstay of treatment of triple-negative breast cancer; however, it is significantly limited by the associated side effects. PD-1/PD-L1 immune checkpoint inhibition therapy (ICI) has been a breakthrough for this patient population in recent years. PD-L1 expression is crucial in immunotherapy since it is a major predictor of PD-1/PD-L1 antibody response, emphasizing the significance of monitoring PD-L1 expression. Nonetheless, it is hard to assess the expression of PD-L1 before surgery, which has highlighted the urgency for a precise and noninvasive approach. Herein, we prepared a dual-mode imaging nanoparticle probe to detect PD-L1. The particle size, zeta potential, biocompatibility, and imaging ability of NPs were characterized. The synthesized NPs showed slight cytotoxicity and good T2 relaxivity. The targeted NPs accumulated more in 4T1 cells than nontargeted NPs in vitro. The in vivo experiment further demonstrated the distribution of targeted NPs in tumor tissues, with changes in NIRF and MR signals observed. Our study indicated that SPIO-aPD-L1-Cy5.5 NPs can be used to monitor PD-L1 expression in breast cancer as NIRF/MR contrast agents.

Development of an Immuno-SPECT/Fluorescent Bimodal Tracer Targeting Human or Murine PD-L1 on Preclinical Models

“…In recent years, growing interest in PD-L1 biomarkers has spurred the development of various biomarkers, mainly using immunoagents − or nanoparticles. − At the same time, the exploration of new hybrid imaging agents to make the most of existing imaging methods has grown considerably. − Despite these advances, the field of bimodal imaging of PD-L1 is still in its infancy. Studies on this field have largely revolved around nanoparticles with ferromagnetic properties for MRI imaging. − It is worth noticing that a few studies have focused on the use of small organic probes for bimodal imaging but with the need for repeated injection of probes for each modality. , At present, the development of bimodal organic probes enabling dual imaging in a single injection for PD-L1 imaging remains relatively limited. , …”