Targeted theranostic platinum(IV) prodrug with a built-in aggregation-induced emission light-up apoptosis sensor for noninvasive early evaluation of its therapeutic responses in situ.

Abstract

Targeted drug delivery to tumor cells with minimized side effects and real-time in situ monitoring of drug efficacy is highly desirable for personalized medicine. In this work, we report the synthesis and biological evaluation of a chemotherapeutic Pt(IV) prodrug whose two axial positions are functionalized with a cyclic arginine-glycine-aspartic acid (cRGD) tripeptide for targeting integrin αvβ3 overexpressed cancer cells and an apoptosis sensor which is composed of tetraphenylsilole (TPS) fluorophore with aggregation-induced emission (AIE) characteristics and a caspase-3 enzyme specific Asp-Glu-Val-Asp (DEVD) peptide. The targeted Pt(IV) prodrug can selectively bind to αvβ3 integrin overexpressed cancer cells to facilitate cellular uptake. In addition, the Pt(IV) prodrug can be reduced to active Pt(II) drug in cells and release the apoptosis sensor TPS-DEVD simultaneously. The reduced Pt(II) drug can induce the cell apoptosis and activate caspase-3 enzyme to cleave the DEVD peptide sequence. Due to free rotation of the phenylene rings, TPS-DEVD is nonemissive in aqueous media. The specific cleavage of DEVD by caspase-3 generates the hydrophobic TPS residue, which tends to aggregate, resulting in restriction of intramolecular rotations of the phenyl rings and ultimately leading to fluorescence enhancement. Such noninvasive and real-time imaging of drug-induced apoptosis in situ can be used as an indicator for early evaluation of the therapeutic responses of a specific anticancer drug.

• Authors: Youyong Yuan, Ryan T K Kwok, Ben Zhong Tang, Bin Liu
• Journal: Journal of the American Chemical Society (J Am Chem Soc) Vol. 136 Issue 6 Pg. 2546-54 (Feb 12 2014) ISSN: 1520-5126 [Electronic] United States
• PMID: 24437551 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Coordination Complexes
• Fluorescent Dyes
• Organoplatinum Compounds
• Prodrugs
• Platinum
• Caspase 3

Topics

• Apoptosis
• Caspase 3 (chemistry)
• Chromatography, High Pressure Liquid
• Coordination Complexes (chemical synthesis, chemistry)
• Drug Delivery Systems
• Fluorescent Dyes (chemistry)
• Humans
• Magnetic Resonance Spectroscopy
• Molecular Imaging
• Molecular Structure
• Organoplatinum Compounds (chemistry)
• Platinum (chemistry)
• Prodrugs (chemistry)