Composite Conjugated Polymer/Fullerene Nanoparticles as Sensitizers in Photodynamic Therapy for Cancer

The fabrication and study of composite conjugated polymer nanoparticles doped with fullerene for application in photodynamic therapy (PDT) is reported. The nanoparticles are not intrinsically cytotoxic and show specificity towards cancer cells without surface modification. The high absorption cross-section and efficient charge transfer from conjugated polymer to fullerene in the composite nanoparticles results in only moderate light levels being necessary for PDT. The PDT scheme was tested in vitro for MDA-MB-231 (human breast cancer), A549 (human lung cancer), and OVCAR3 (human ovarian cancer) cell lines. While the treatment was observed to be only marginally effective for the MDA-MB-231 cell line, 60 % and complete cell death was observed for the A549 and OVCAR3 cell lines, respectively. Differences in PDT efficiency are attributed to the difference in nanoparticle uptake between these cell lines, and is potentially related to differences in metabolic rate. Through live/dead cell staining apoptotic cell death was observed for OVCAR3. This is a promising finding for potential development of treatment for ovarian cancer by the PDT scheme discussed herein. © 2013, Springer Science+Business Media New York.