Upconversion Nanostructures Applied in Theranostic Systems

Area of Science:

• Nanotechnology
• Materials Science
• Biomedical Engineering

Background:

• Upconversion (UC) nanostructures convert low-energy near-infrared (NIR) light to higher-energy visible or UV light.
• These nanostructures are being explored for theranostic applications, combining diagnosis and therapy.
• Two main types exist: lanthanide (Ln)-doped UC nanostructures and organic molecular-based UC nanostructures utilizing triplet-triplet annihilation (TTA).

Purpose of the Study:

• To review major UC mechanisms in different nanostructures.
• To discuss the design and fabrication of Ln-doped and TTA UC nanostructures for theranostics.
• To summarize current progress and future insights in UC nanostructures for theranostics.

Main Methods:

• Review of existing literature on UC mechanisms.
• Discussion of design and fabrication strategies for UC nanostructures.
• Summary and analysis of applications in bioimaging, chemotherapy, phototherapy, and drug delivery.

Main Results:

• Ln-doped UC nanostructures can be functionalized for targeted therapies.
• TTA UC nanostructures offer high quantum yields and low excitation power requirements.
• UC nanostructures are effective in tumor-targeted bioimaging, chemotherapy, image-guided diagnosis, phototherapy, and controlled drug release.

Conclusions:

• UC nanostructures hold significant potential for advanced theranostic applications.
• Continued development of emerging UC nanostructures will further enhance their theranostic capabilities.
• The review provides a comprehensive overview of UC nanostructures for diagnosis and therapy.