POS8-1461
Multifunctional NIR-Activated Upconversion Nanoplatform for MRI-Guided Synergistic Photodynamic and Photothermal Therapy
Topic
S8. Frontiers of Functional Polymers in Biology and Medicine
When and Where
Oct 1, 2026
08:30 - 09:30
Room 301 (Grand Ballroom)
Session Chairs
Jinkee HONG
Ki Su KIM
Presenter(s)
AJITH KUMAR LAKSHMANAN (Chungnum National University)
Co-Author(s)
Abstract
Cancer theranostics, which integrates disease diagnosis and therapy within a single multifunctional platform, has emerged as a promising strategy for precision oncology. Among various non-invasive therapeutic modalities, photodynamic therapy (PDT) has attracted considerable attention because of its high spatiotemporal selectivity, minimal invasiveness, and relatively low systemic toxicity. In PDT, a photosensitizer (PS) is activated by light of an appropriate wavelength to generate reactive oxygen species (ROS), particularly singlet oxygen, which induces cancer cell death. However, the clinical application of conventional PDT is restricted by the shallow tissue penetration of visible light required to activate most organic photosensitizers. In addition, the hypoxic tumor microenvironment limits oxygen-dependent ROS generation, thereby reducing therapeutic efficacy. To address these limitations, we developed a multifunctional theranostic nanoplatform based on lanthanide-doped upconversion nanoparticles (UCNPs) conjugated with two complementary photosensitizing components, an organic xanthene-based photosensitizer and a metallophthalocyanine-based photosensitizing catalyst. Upon near-infrared (NIR) irradiation, the UCNPs convert deeply penetrating NIR light into visible emission, enabling the activation of both photosensitizing components through luminescence resonance energy transfer. The activated xanthene-based photosensitizer efficiently generates singlet oxygen for PDT, whereas the metallophthalocyanine-based component provides complementary photosensitizing and catalytic functions by generating additional ROS and promoting the decomposition of endogenous hydrogen peroxide (H2O2). This catalytic activity may alleviate tumor hypoxia and enhance oxygen-dependent photodynamic effects, thereby improving the overall therapeutic efficacy. In addition to these therapeutic functions, the incorporation of Gd ions into the UCNP host lattice provides magnetic resonance imaging (MRI) contrast capability, enabling non-invasive tumor visualization and potentially facilitating imaging-assisted treatment monitoring.
