Dose-dependent In Vitro Cytotoxic Effects of Phosphorus Doped Graphene Oxide Titanium Oxide Nanocomposite (P-GO-TiO₂ NC) on Caprine Wharton's Jelly Derived Mesenchymal Stem Cells (WJ-MSCs) and Erythrocytes

The present investigation was conducted to evaluate the dose dependent (100, 50, 25, 10 and 0 μg/ml) cytotoxic effects of phosphorus doped graphene oxide titanium oxide nanocomposite (P-GO-TiO₂ NC) on caprine Wharton`s jelly-derived mesenchymal stem cells (WJ-MSCs) by observing cell morphology, viability, growth kinetics, PDT (population doubling time), MTT (Tetrazolium dye 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide) and hemolysis assay using caprine erythrocytes. The caprine WJ-MSCs exhibited fibroblastoid morphology which was changed significantly as cells detached from culture surface at 100 and 50 μg/ml doses while 25 and 10 μg/ml did not altered cell morphology after 48 and 72 hrs exposure as compared to control. Viable cell number after 48 and 72 hrs of incubation with P-GO-TiO₂ NC in 25 μg/ml dose was significantly (P<0.01) higher while it was significantly (P<0.01) lower at 100 and 50 μg/ml doses as compared to 10 μg/ml and control. Caprine WJ-MSCs PDT was significantly (P<0.05) increased at 100 and 50 μg/ml doses with significantly (P<0.05) altered shape of growth curve as compared to 25, 10 and 0 μg/ml doses of P-GO-TiO₂ NC. Metabolically active caprine WJ-MSCs were significantly (P<0.01) increased at 25 and 10 μg/ml doses, while it was significantly (P<0.01) decreased at 100 and 50 μg/ml doses as compared to control, which was determined by MTT assay. Erythrocyte hemolysis assay revealed that P-GO-TiO₂ NC significantly (P<0.05) destructed the caprine erythrocytes at 100 μg/ml doses as compared to 50, 25, 10 and 0 μg/ml doses. It is concluded that P-GO-TiO₂ NC at 25 and 10 μg/ml doses are biocompatible and enhance caprine WJ-MSCs growth as compared to 100 and 50 μg/ml doses.