Label-free assessment of Panc-1 cells viability and changes in metabolic fluorophores followed by radiodynamic therapy (RDT)

Photodynamic therapy (PDT) is an established treatment which uses a photosensitiser drug and light source to destroy superficial lesions. This therapy is not applicable to deep-seated tumours due to limited light penetration. Recently, it has been found that replacing light in PDT with X-rays (thus named radiodynamic therapy (RDT)) can stimulate nanoformulated photosensitiser drugs including Verteporfin and generate reactive oxygen species to kill the cancer cells. Herein, we investigated aspects of cellular metabolic processes after RDT in comparison with PDT and radiotherapy using label-free hyperspectral autofluorescence microscopy and image analysis. Biochemical signatures of metabolically relevant fluorophores (NAD(P)H, flavins, and optical-redox-ratio) were identified by developing a semi-unsupervised unmixing method combining supervised and unsupervised unmixing in a novel way.