Present experiment was aimed to study the cytotoxic effects of Graphene oxide-iron oxide nanocomposite on caprine Wharton’s

jelly derived mesenchymal stem cells (WJ-MSCs). Ex vivo caprine WJ-MSCs were isolated and cultured. Cytotoxic effects of different concentrations of GO-Fe2O3 nanocomposite (10 μg/ml, 50 μg/ml and 100 μg/ml) were analyzed by observing cell morphology, cell viability, growth kinetics, population doubling time and colony forming unit (CFU) assay in caprine WJ-MSCs. Morphological alterations in nanocomposite-treated cells (50 μg/ml and 100 μg/ml GO-Fe2O3) were distinct as compared to lower dose (10 μg/ml GO- Fe2O3) and control group. Cell viability assay indicated a highly signifi cant (P<0.01) decrease in live cell number when they were exposed to 100 μg/ml and 50 μg/ml GO- Fe2O3 nanocomposite and these effects were intensifi ed with time (24 h & 48 h post-exposure). Retarded growth rate and signifi cant (P<0.01) increase in population doubling time (PDT) of exposed cells (50 μg/ml and 100 μg/ml) were observed as compared to control group and low dose treatment group (10 μg/ml). Colony forming unit (CFU) assay indicated that cells treated with 50 μg/ml and 100 μg/ml nanocomposite formed less number of clones than control group and 10 μg/ml treatment group. On the basis of results, we conclude that lower doses (10 μg/ml) of the nanocomposite are safer in caprine WJ-MSCs however with increasing doses of nanocomposite (50 μg/ml & 100 μg/ml) the potential toxicity increases. Present study reports the tolerable doses of GO-Fe2O3 nanocomposite which will

help in future applications like tracking, imaging and differentiation of caprine WJ-MSCs.