Aza-BODIPY based polymeric nanoparticles for cancer cell imaging

Area of Science:

• Biomedical Engineering
• Materials Science
• Optical Imaging

Background:

• Hydrophobicity of near-infrared (NIR) fluorescent dyes limits their application in cancer imaging.
• Developing water-soluble and biodegradable imaging agents is crucial for deep-tissue visualization.

Purpose of the Study:

• To create a water-suspendable and biodegradable NIR-light-activating aza-BODIPY (AZB-NO2) encapsulated in polymeric nanoparticles.
• To evaluate the potential of these nanoparticles as deep-tissue imaging agents for cancer applications.

Main Methods:

• Emulsification-solvent evaporation method was used to encapsulate AZB-NO2 dye within polycaprolactone (PCL) and Kolliphor P188 surfactant.
• Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDS) were employed for characterization.
• The nanoparticles (AZB-NO2@PCL) were tested for fluorescence imaging in human glioblastoma (U-251) cell lines and 3D cell cultures.

Main Results:

• Spherical nanoparticles (average size 201 nm) with homogeneous dye distribution were successfully prepared.
• Nanoparticles with 0.8 mg dye loading exhibited the highest fluorescence quantum yield.
• AZB-NO2@PCL demonstrated efficient localization and enhanced fluorescence signal within U-251 cells over time, including in 3D tumor models.

Conclusions:

• Encapsulation of hydrophobic aza-BODIPY dye in biodegradable PCL nanoparticles significantly improves water-suspendability.
• The developed biocompatible nanoparticles are effective for cancer cell imaging, offering bright fluorescence and potential for deep-tissue applications.