A highly selective iron oxide-based imaging nanoparticle for long-term monitoring of drug-induced tumor cell apoptosis
The ability to visualize and quantify apoptosis in vivo is critical to monitoring disease response to treatment and providing prognosis information. However, the application of current apoptosis labeling probes faces significant challenges including nonspecific tissue labeling, short monitoring windows, and low signal to noise ratios. Here we report a highly specific apoptosis labeling nanoparticle (NP) probe with pisum sativum agglutinin (PSA) as tumor targeting ligand for prolonged in vivo apoptosis imaging. The NP (namely, IONP-Neu-PSA) consists of a magnetic iron oxide core (IONP) conjugated with PSA, and a reporter fluorophore. IONP-Neu-PSA demonstrated minimal cytotoxicity and high labeling specificity towards apoptotic cells in vitro. When applied in vivo, IONP-Neu-PSA tracks apoptosis for a prolonged period of two weeks with near-IR imaging for the increased signal-to-noise ratios. Moreover, IONP-Neu-PSA possess T2 contrast enhancing properties that can potentially enable apoptosis detection by magnetic resonance imaging (MRI). The high specificity for apoptotic cells, sustained fluorescent signal, and non-invasive imaging capability exhibited by IONP-Neu-PSA could provide a versatile tool for cancer treatment monitoring and pathological research.
- This article is part of the themed collection: Biomaterials for Imaging and Sensing