SCD and melanoma: Although, we did not measure directly the Zeta potential value of the respective CEIN sample(s) as well as normal and cancer (melanoma) cells studied to data, a battery of alternative cytotoxicity tests including LDH leakage assays following Annexin V-FITC/PI and Calcein AM/PI labeling were applied for all the four types of carbon-encapsulated iron nanomaterials to study CEIN-related membrane cytotoxicity effects due to differences in SCD.