Heavy-Atom-Free Aza-BODIPY Polymeric Nanoparticles for Theranostic-Guided Photodynamic Cancer Therapy

Area of Science:

• Biomedical Engineering
• Materials Science
• Nanotechnology

Background:

• Photodynamic therapy (PDT) offers noninvasive cancer treatment but faces challenges with photosensitizer toxicity.
• Conventional photosensitizers often contain heavy atoms, increasing risks and limiting clinical use.

Purpose of the Study:

• To develop a safe, heavy-atom-free photosensitizer for enhanced PDT.
• To create a nanoparticle (NP) platform for synergistic photodynamic and photothermal therapy.
• To evaluate the efficacy and biocompatibility of the novel NP system for cancer treatment.

Main Methods:

• Synthesized a heavy-atom-free aza-BODIPY derivative conjugated to mPEG-SA, forming self-assembled nanoparticles (mPEG-SA-AB NPs).
• Evaluated NP biocompatibility, photocytotoxicity, intracellular reactive oxygen species (ROS) generation, and cellular uptake in 4T1 breast cancer cells.
• Utilized optical coherence tomography (OCT) for real-time monitoring and in vivo fluorescence imaging in tumor-bearing mice to assess therapeutic efficacy and biodistribution.

Main Results:

• mPEG-SA-AB NPs demonstrated high biocompatibility in dark conditions and significant photocytotoxicity upon red light irradiation.
• NPs showed enhanced cellular uptake and accumulation in endocytic compartments.
• In vivo studies confirmed targeted tumor accumulation and superior antitumor efficacy (2.5-fold increase) compared to the free dye, with excellent hemocompatibility and systemic biocompatibility.

Conclusions:

• mPEG-SA-AB NPs represent a safe and effective nanotheranostic platform for cancer treatment.
• The synergistic photodynamic and mild photothermal effects enhance therapeutic outcomes.
• This platform holds significant translational potential for improved cancer diagnosis and therapy.