ROS-Responsive Nanoprobes for Bimodal Imaging-Guided Cancer Targeted Combinatorial Therapy

Purpose: Chemotherapy mediated by Reactive oxygen species (ROS)-responsive drug delivery systems can potentially mitigate the toxic side effects of chemotherapeutic drugs and significantly enhance their therapeutic efficacy. However, achieving precise targeted drug delivery and real-time control of ROS-responsive drug release at tumor sites remains a formidable challenge. Therefore, this study aimed to describe a ROS-responsive drug delivery system with specific tumor targeting capabilities for mitigating chemotherapy-induced toxicity while enhancing therapeutic efficacy under guidance of Fluorescence (FL) and Magnetic resonance (MR) bimodal imaging. Methods: Indocyanine green (ICG), Doxorubicin (DOX) prodrug pB-DOX and Superparamagnetic iron oxide (SPIO, Fe3O4) 3 O 4 ) were encapsulated in poly(lactic-co-glycolic acid) (PLGA) by double emulsification method to prepare ICG/ pB-DOX/ Fe3O4/ 3 O 4 / PLGA nanoparticles (IBFP NPs). The surface of IBFP NPs was functionalized with mammaglobin antibodies (mAbs) by carbodiimide method to construct the breast cancer-targeting mAbs/ IBFP NPs (MIBFP NPs). Thereafter, FL and MR bimodal imaging ability of MIBFP NPs was evaluated in vitro and in vivo. Finally, the combined photodynamic therapy (PDT) and chemotherapy efficacy evaluation based on MIBFP NPs was studied. Results: The multifunctional MIBFP NPs exhibited significant targeting efficacy for breast cancer. FL and MR bimodal imaging clearly displayed the distribution of the targeting MIBFP NPs in vivo. Upon near-infrared laser irradiation, the MIBFP NPs loaded with ICG effectively generated ROS for PDT, enabling precise tumor ablation. Simultaneously, it triggered activation of the pB-DOX by cleaving its sensitive moiety, thereby restoring DOX activity and achieving ROS-responsive targeted chemotherapy. Furthermore, the MIBFP NPs combined PDT and chemotherapy to enhance the efficiency of tumor ablation under guidance of bimodal imaging. Conclusion: MIBFP NPs constitute a novel dual-modality imaging-guided drug delivery system for targeted breast cancer therapy and offer precise and controlled combined treatment options.