“…Positively charged IONPs were shown to be more toxic, since they undergo nonspecific interactions and adsorptive endocytosis with the negatively charged cell membrane, thus increasing their intracellular accumulation and affecting cell membrane integrity [ 218 ]. Other factors such as concentration, type of coating, form of administration, as well as the cell line may explain the different results for IONPs toxicity [ 21 , 22 , 23 , 25 , 26 , 66 , 71 , 72 , 96 , 97 , 98 , 163 , 214 , 215 , 219 , 220 , 221 , 222 , 223 , 224 , 225 , 226 , 227 , 228 , 229 , 230 , 231 , 232 , 233 , 234 , 235 , 236 , 237 , 238 , 239 , 240 , 241 , 242 , 243 , 244 , 245 , 246 , 247 , 248 ], as shown in Table 1 .…”