Tumor-microenvironmental-response Bi-functional molecules for efficient imaging and anti-tumor activity therapy

All-in-one nanotheranostic platform based on tumor microenvironment: new strategies in multimodal imaging and therapeutic protocol

Conventional tumor diagnosis and treatment approaches have significant limitations in clinical application, whereas personalized theranostistic nanoplatforms can ensure advanced diagnosis, precise treatment, and even a good prognosis in cancer. Tumor microenvironment (TME)-targeted therapeutic strategies offer absolute advantages in all aspects compared to tumor cell-targeted therapeutic strategies. It is essential to create a TME-responsive all-in-one nanotheranostic platform to facilitate individualized tumor treatment. Based on the TME-responsive multifunctional nanotheranostic platform, we focus on the combined use of multimodal imaging and therapeutic protocols and summary and outlooks on the latest advanced nanomaterials and structures for creating the integrated nanotheranostic system based on material science, which provide insights and reflections on the development of innovative TME-targeting tools for cancer theranostics.

Dual-Functional AIE Fluorescent Probe for Visualization of Lipid Droplets and Photodynamic Therapy of Cancer

Abnormal lipid droplets (LDs) are known to be intimately bound with the occurrence and development of cancer, allowing LDs to be critical biomarkers for cancers. Aggregation-induced emission luminogens (AIEgens), with efficient reactive oxygen species (ROS) production performance, are prime photosensitizers (PSs) for photodynamic therapy (PDT) with imaging. Therefore, the development of dual-functional fluorescent probes with aggregation-induced emission (AIE) characteristics that enable both simultaneous LD monitoring and imaging-guided PDT is essential for concurrent cancer diagnosis and treatment. Herein, we reported the development of a novel LD-targeting fluorescent probe (TDTI) with AIE performance, which was expected to realize the integration of cancer diagnosis through LD visualization and cancer treatment via PDT. We demonstrated that TDTI, with typical AIE characteristics and excellent photostability, could target LDs with high specificity, which enables the dynamic tracking of LDs in living cells, specific imaging of LDs in zebrafish, and the differentiation of cancer cells from normal cells for cancer diagnosis. Meanwhile, TDTI exhibited fast ROS generation ability (achieving equilibrium within 60 s) under white light irradiation (10 mW/cm2). The cell apoptosis assay revealed that TDTI effectively induced growth inhibition and apoptosis of HeLa cells. Further, the results of PDT in vivo indicated that TDTI had a good antitumor effect on the tumor-bearing mice model. Collectively, these results highlight the potential utility of the dual-functional fluorescent probe TDTI in the integrated diagnosis and treatment of cancer.

A bifunctional agent for efficient imaging of PD-L1 and antimelanoma activity

Immune checkpoint inhibitors targeting PD-L1 lead to challenging patterns of efficacy and toxicity. Herein, by focusing on tracing the molecular biomarker of response to efficacy, we formulated a central hypothesis for the construction of theranostic functional monoclonal antibody incorporation with tracing ability based on fluorescence turn-on and controllable release strategies. Functional atezolizumab was constructed by in situ assembly of both biorthogonal group and controllable release group. The theranostic monoclonal antibodies achieved quantitative monitoring of PD-L1 on cells with different expression levels through biorthogonal light-up fluorescence, followed by the release of atezolizumab in combination with high tumor reduction conditions to promote immune activation. The combination of bio-orthogonal reaction-driven fluorescence turn-on and tumor microenvironment-responsive controllable release afforded theranostic bifunctional monoclonal antibodies for the detection of PD-L1 and combination therapy. Remarkably, these novel theranostics might be used as probes for fluorescent imaging and simultaneously achieving potent antitumor efficacy.

Discovery of Imaging and Therapeutic Integration Bifunctional Molecules Based on Bio-Orthogonal Reaction and Releasable Disulfide Bond

The application of conventional fluorescent probes in living cells has been limited by excess fluorescence interference, reduced selectivity, and poor permeability. Herein, we describe a convenient solution for overcoming the above limitations based on bio-orthogonal reactions and releasable linkers that provide bifunctional molecules for imaging and therapeutic integration. To reduce the interference of excess fluorescent moieties, a bio-orthogonal reaction was applied to activate the fluorescence of the active parent drugs without fluorophores. Moreover, disulfide bonds were incorporated as releasable linkers. After imaging the target protein, the newly yielded fluorophore could be released from the active drugs based on the highly reducing conditions of the tumor. Thus, these bifunctional molecules are comparable in therapeutic activity to the parent drug. These novel imaging and therapeutic integration molecules could be used to realize imaging-aided diagnosis and perform efficient real-time monitoring of cancer cells. Our findings are expected to enable efficient and specific imaging and real-time in vivo prognostic monitoring in the clinic.