Pharmacokinetics and bio-distribution of differently functionalized Carbon nanotube in Zebrafish, Danio rerio

Carbon nanotubes (CNTs) are promising nanomaterials with applications in biomedicine, including drug delivery and biosensing, due to their stability, biocompatibility, and ease of surface modification. However, toxicity concerns from their manufacturing limit their use. Functionalizing CNTs can reduce toxicity and enhance transport in physiological systems, while their optimal dosing is influenced by biodistribution and pharmacokinetics. In this study, multiwalled carbon nanotubes (MWCNTs) were synthesized via Chemical Vapor Deposition (CVD) and functionalized with Bovine Serum Albumin (BSA) and Fe₃O₄. MWCNTs were characterized using various techniques, and their 96 h lethal concentration was assessed through the Zebrafish Embryo Toxicity Test (ZFET). The LC₅₀ and LC₂₀ values for Fe₃O₄-MWCNTs were 685.51 mg/L and 198.3 mg/L, while for BSA-MWCNTs, they were 401.25 mg/L and 150.45 mg/L, respectively. Genotoxicity analysis showed no DNA damage, and histological examinations of liver, gills, intestine, and brain revealed no major alterations. The pharmacokinetics and biodistribution of BSA-MWCNTs (T1) and Fe₃O₄-MWCNTs (T2) were examined following oral administration in D. rerio. Results indicated longer T^1/2 in blood and gut tissues from the T1 group, and faster clearance in blood compared to gut. By day 28, MWCNTs showed higher accumulation in the liver, followed by the gut and brain. This study delineates the pharmacokinetics and biodistribution, and confirms the optimal dose of MWCNTs, and promotes its application in the field of biomedical research.