Activity of Psoralen-Functionalized Nanoscintillators against Cancer Cells upon X-ray Excitation

We report development of a nanoparticle-based, X-ray-activated anticancer nanodrug composed of yttrium oxide (Y2O3) nanoscintiliators, a fragment of the HIV-1 TAT peptide, and psoralen. In this formulation, X-ray radiation is absorbed by the Y2O3 nanoscintillators, which then emit UVA light. Absorption of UVA photons by nanoparticle-tethered psoralen has the potential to cross-link adenine and thymine residues in DNA. OVA-Induced cross-linking by free psoralen upon activation with OVA light has previously been shown to cause apoptosis in vitro and an immunogenic response in vivo. Studies using the PC-3 human prostate cancer cell line demonstrate that X-ray excitation of these psoralen-functionalized Y2O3 nanosdntillators yields concentration-dependent reductions in cell number when compared to control cultures containing psoralen-free Y2O3 nanoscintillators.