Enhanced Afterglow Performance of Persistent Luminescence Implants for Efficient Repeatable Photodynamic Therapy

Area of Science:

• Biomedical Engineering
• Materials Science
• Oncology

Background:

• Persistent luminescence nanoparticles (PLNPs) offer autofluorescence-free bioimaging.
• Poor afterglow performance of PLNPs limits their use in cancer therapy.

Purpose of the Study:

• To develop injectable persistent luminescence implants (PL implants) for enhanced photodynamic therapy (PDT).
• To create a built-in excitation source for repeatable PDT using PL implants.

Main Methods:

• Synthesized injectable ZGC (ZnGa1.996O4:Cr0.004) PL implants by dissolving ZGC PLNPs in a PLGA/NMP oleosol.
• Evaluated persistent luminescence (PersL) intensity and lifetime in vitro and in vivo.
• Investigated the efficacy of PL implants as an excitation source for repeatable LED and PersL-excited PDT.

Main Results:

• ZGC PL implants exhibited significantly stronger PersL intensity and longer PersL lifetime compared to ZGC PLNPs.
• Intratumorally fixed ZGC PL implants functioned as a repeatable built-in excitation source for PDT.
• Repeatable PDT using ZGC PL implants led to improved therapeutic effectiveness and efficient tumor growth suppression.

Conclusions:

• Injectable ZGC PL implants provide a viable strategy for efficient, repeatable PDT.
• The developed PL implants overcome the limitations of poor afterglow in PLNPs for cancer therapy.
• This approach enables periodically rechargeable, built-in light sources for enhanced tumor treatment.