Abstract

To investigate nanoparticles disposition and elimination, dextrin-coated cadmium sulphide nanoparticles were administered intraperitoneally as a single or multiple doses to rats. Nanoparticles distribution in liver, kidney, heart, lung, muscle, testis, brain, spleen and thymus was investigated up to 90 d after daily administration for 30, 60 and 90 d. Tissue distribution was measured in homogenates as fluorescence intensity by spectrophotometry. Tissue concentrations with time for dextrin-coated cadmium sulphide nanoparticles were plotted and some pharmacokinetics parameters were obtained. Serum biochemical parameters were determined using spectrophotometry. Nanoparticles in tissue samples were visualised under an epifluorescence microscope and histological analysis was also performed. After a single administration in rats, nanoparticles were distributed quickly with a Cmax occurring in the first 72 h in all tissues analysed. The elimination t½ of nanoparticles was less than 12 d in kidney, spleen, lung and brain; however, it was more than 40 d in muscle, liver and testicle with a mean residence time greater than 50 days. Alterations in glucose, triglycerides and alkaline phosphatase, were observed since the first day and continued throughout the 90 d post dose. Biocompatibility study showed that dextrin-coated cadmium sulphide nanoparticles only produced degenerative alterations in testis and chronic inflammation in lungs after continuous administration during the 90 days. In conclusion, dextrin-coated cadmium sulphide nanoparticles are widely distributed in tissues and have a very long residence time without producing significant toxicity. The multi-dose study showed that these produce selective toxicity after administration for a long periods of time. These characteristics make the dextrin-coated cadmium sulphide nanoparticles ideal for theranostic purposes.