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A Dendron-Based Fluorescence Turn-On Probe for Tumor Detection
Changren Liu1, Ling'e Zhang1, Sensen Zhou1
1Department of Polymer Science & Engineering, College of Chemistry & Chemical Engineering, Nanjing University, Nanjing, 210023, P.R. China.
Abstract:
Specifically amplifying the emission signals of optical probes in tumors is an effective way to improve the tumor-imaging sensitivity and contrast. In this paper, the first case of dendron-based fluorescence turn-on probes mediated by a Förster resonance energy transfer (FRET) mechanism is reported. Dendrons up to the fourth generation with a hydrophilic oligo(ethylene glycol) scaffold are synthesized by a solid-phase synthesis strategy, and show precise and defect-free chemical structures. To construct the fluorescence turn-on probe, one Cy5.5 molecule is conjugated to the focal of a G3 dendron through a robust linkage and eight Black Hole Quencher 3 (BHQ-3) molecules are conjugated to its periphery through a PEG chain bearing a reductively cleavable disulfide linkage. By in vitro and in vivo experiments, it is demonstrated that the fluorescence of the dendron-based probe can be activated effectively and rapidly in the reductive environments of tumor cells and tissues, and the probe thus exhibits amplified tumor signals and weak normal tissue signals. Compared with the reported nanoscale turn-on probes, the dendron-based probe has several significant advantages, such as well-defined chemical structure, precisely controllable fluorophore/quencher conjugation sites and ratio, desirable chemical stability, and reproducible pharmacokinetic and pharmacological profiles, and is very promising in tumor detection.
Insights
This study introduces novel dendron-based probes that enhance tumor imaging sensitivity. These probes utilize a fluorescence turn-on mechanism activated in tumor environments, improving cancer detection.
Area of Science:
- Biomedical Engineering
- Nanotechnology
- Organic Chemistry
Background:
- Optical probes are crucial for sensitive tumor imaging.
- Current probes often lack sufficient sensitivity and contrast.
- Amplifying emission signals in tumors is key to improved detection.
Purpose of the Study:
- To develop and characterize novel dendron-based fluorescence turn-on probes.
- To investigate the Förster resonance energy transfer (FRET) mechanism for probe activation.
- To evaluate the probe's efficacy in tumor imaging in vitro and in vivo.
Main Methods:
- Synthesis of fourth-generation dendrons with oligo(ethylene glycol) scaffolds via solid-phase synthesis.
- Conjugation of a Cy5.5 fluorophore and eight Black Hole Quencher 3 (BHQ-3) molecules to the dendron structure.
- Utilizing a reductively cleavable disulfide linkage for controlled probe activation.
- In vitro and in vivo experiments to assess probe performance in tumor environments.
Main Results:
- Dendron-based probes exhibit precise, defect-free chemical structures.
- Fluorescence is rapidly activated in the reductive environments of tumor cells and tissues.
- The probes show amplified tumor signals and reduced normal tissue signals.
- Demonstrated advantages over existing nanoscale probes, including well-defined structures and controllable conjugation.
Conclusions:
- Dendron-based fluorescence turn-on probes offer a promising new strategy for enhanced tumor detection.
- The FRET-mediated mechanism and specific design enable sensitive and selective tumor imaging.
- The probes possess desirable chemical stability and reproducible pharmacokinetic profiles for clinical translation.
