Internal Loading of Environmentally Friendly InP/ZnSe/ZnS QDs in Bovine Milk Exosomes

Area of Science:

• Nanotechnology
• Biotechnology
• Materials Science

Background:

• Stable and reliable fluorescence tracking is crucial for biological applications.
• Existing labeling methods often lack efficiency or biocompatibility.

Purpose of the Study:

• To develop a cadmium-free, eco-friendly quantum dot (QD) platform for efficient exosome labeling.
• To ensure QD stability and biocompatibility within exosomes for enhanced bioimaging.

Main Methods:

• Synthesized InP/ZnSe/ZnS quantum dots (QDs) using a hot-injection method.
• Modified QD surface ligands (oleic acid, MUA, PEG) for water dispersibility and exosome internalization.
• Purified exosomes using electrophoretic oscillation-assisted tangent flow filtration (EPOTF).
• Optimized ultrasonic treatment for QD internalization without structural damage.

Main Results:

• QD-exosomes exhibited 89% photoluminescent intensity retention under laser exposure, significantly outperforming conventional PKH67 labels (10%).
• Confocal microscopy confirmed efficient QD-exosome uptake into HaCaT cells with perinuclear localization.
• TEM imaging verified structural integrity of exosomes post-QD internalization.

Conclusions:

• The developed QD-exosome platform offers a robust, scalable, and eco-friendly solution for bioimaging.
• This method is suitable for real-time imaging, targeted drug delivery, and nanomedicine.
• The enhanced photostability and biocompatibility open new avenues in cellular tracking and therapeutic applications.