CASP7 and squamous cell carcinoma: As a result of the various cellular processes induced by the PPT component-loaded nanoparticles, effector caspase-3 and caspase-7 activation, as well as reactive oxygen species (ROS) induction, showed good selectivity, being more efficient in the A-431 epidermoid carcinoma cells than in the normal HaCaT keratinocytes.