Faculty, Staff and Student Publications
Publication Date
3-28-2025
Journal
Science Advances
Abstract
Inadequate light penetration in tissues restricts photodynamic therapy to treating only superficial tumors. To enable x-ray-excited photodynamic therapy (XPDT) that targets deep-seated tumors, we synthesized a nanoscintillator-photosensitizer complex containing 5% Eu-doped Y2O3 fluorescing at 611 nanometers and decorated with SiO2 containing the scintillation-coupled photosensitizer methylene blue and a polyethylene glycol coating [PEGylated Y2O3:Eu@SiO2-methylene blue (pYSM)]. When irradiated, pYSMs generate singlet oxygen species in vitro, causing cytotoxicity with hallmarks of immunogenic cell death (calreticulin translocation to the cell membrane). Intravenously administered pYSMs home passively to pancreatic tumor xenografts and, upon 10 gray irradiation, cause significant tumor regression (P < 0.01). On combining XPDT with anti-PD1 immunotherapy, a distant nonirradiated tumor also regresses via an increase in intratumoral activated CD8+ cytotoxic T cells. Collectively, we advance a systemically delivered XPDT strategy that mediates an antitumor effect in both irradiated and nonirradiated (abscopal) tumors when coupled with immunotherapy, converting an immunologically "cold" tumor to an immunologically "hot" tumor.
Keywords
Animals, Mice, Humans, X-Rays, Yttrium, Photochemotherapy, Cell Line, Tumor, Photosensitizing Agents, Xenograft Model Antitumor Assays, Pancreatic Neoplasms, Nanoparticles, Immunotherapy
DOI
10.1126/sciadv.adr4008
PMID
40138411
PMCID
PMC11939067
PubMedCentral® Posted Date
3-26-2025
PubMedCentral® Full Text Version
Post-print
Published Open-Access
yes
Included in
Bioinformatics Commons, Biomedical Informatics Commons, Genetic Phenomena Commons, Medical Genetics Commons, Oncology Commons