In vitro and In vivo evaluation of green-hydrothermal synthesized ZnO nanoparticles

ZnO nanoparticles synthesized using Gallic acid isolated from Phyllanthus emblica aqueous extract that designated as Pe ZnO, was subjected for structural and morphological characterization. For in vitro cyto-toxicity assessment of Pe ZnO, Hemolytic assay and Cell Counting Kit assay (CCK 8) on balb 3T3 fibroblasts were conducted while silkworm Bombyx mori larvae were used for in vivo bio-toxicity assay. In dentistry, clinically advocated ZnO (presented as D ZnO) of similar to 2 mu m size was used as control. Characterization results revealed that Pe ZnO is highly crystalline with hexagonal wurtzite structure and morphologically spherical with an average size of 38 nm as confirmed by X-ray diffraction, electron microscopy and dynamic light scattering techniques. Haemolysis assay at all the tested concentrations exhibit that, lysis of Red Blood Cells by Pe ZnO remained well within toxicity limit of 3% whereas D ZnO showed similar to 5.2% hemolysis. Interestingly, Pe ZnO nanoparticles caused less than 36% growth inhibition of 3T3 cells at the highest concentration (2 mu l) against 44% by D ZnO. Notably, in vivo study showed 26.67 and 96.67% death of the larvae at highest concentration 0.032 mg/mL of Pe ZnO and D ZnO respectively indicating Pe ZnO is less toxic than commercially available ZnO. Thus, we proved that green hydrothermally synthesized ZnO (PeZnO) is highly biocompatible and therefore propose to consider as potent compound for further evaluation using mammalian models followed by clinical trials.