Stem cell nanotechnology (SCN) is an important scientific field to guide stem cell-based research of nanoparticles. Currently, nanoparticles (NPs) have a rich spectrum regarding the sources from which they are obtained (metallic, polymeric, etc.), the methods of obtaining them (physical, chemical, biological), and their shape, size, electrical charge, etc. properties. It is also essential to expand green synthesis applications for the use of NPs in the field of biomedical sciences. For this purpose, there is a need to produce NPs using biological sources (plant, microorganism, algae, yeast etc.…), characterization and investigation of their effects on biological activities of stem cells. This process involves long and laborious procedures, and there may be differences in methods between individual laboratories. In this protocol, biofabrication and characterization of ZnO NPs using dried leaves of Camellia sinensis is described. This experimental setup includes conventional and novel methods that can be applied to biofabricate and characterize the NPs and to examine the viability, apoptotic, and necrotic effects on human adipose tissue-derived mesenchymal stem cells (ADMSCs) in vitro.