Research Article For reprint orders, please contact: reprints@futuremedicine.com Molecular insight to in vitro biocompatibility of phytofabricated copper oxide nanoparticles with human embryonic kidney cells Puja Kumari 1 , Pritam Kumar Panda 2 , Ealisha Jha 3 , Nandini Pramanik 1 , Kumari Nisha 1 , Khushboo Kumari 1 , Nikita Soni 4 , M Anwar Mallick 1 & Suresh K Verma* ,5 1 Advance Science & Technology Research Centre, Vinoba Bhave University, Hazaribagh, Jharkhand, 825301, India 2 Division of Pediatric Hematology & Oncology, University Children’s Hospital, University of Freiburg, 79106, Germany 3 Department of Physics & Physical Oceanography, Memorial University of Newfoundland, St. John’s, Newfoundland & Labrador, NL A1C 5S7 Canada 4 School of Biotechnology & Bioinformatics, D. Y. Patil (deemed to be university), Navi Mumbai, India 5 School of Biotechnology, KIIT University, Bhubaneswar, Odisha, 751024, India *Author for correspondence: sureshverma22@gmail.com Aim: To investigate the biocompatibility of green synthesized copper oxide nanoparticles (CuO Np) us- ing foral extract of Calotropis gigantea in room condition. Materials & methods: Green synthesized and characterized CuO Np was evaluated for their cellular and molecular biocompatibility by experimentally and computational molecular docking. Results: Synthesized CuO NP was found to have a size 32 ± 09 nm with ζ potential -35 ± 12 mV. LC 50 value was found to be 190 μg/ml. In vitro and in silico cytotoxicity analysis with HEK293 cells revealed the cytotoxic effect of CuO Np as consequences of interaction with histidine and arginine amino acid residues of Sod3 and p53 proteins via hydrogen bond of length 3.09 and 3.32 ˚ A leading to oxidative stress ensuing toward apoptosis and cell cycle arrest. Conclusion: The outcomes proved the synthesized material as an alternative to the conventional method of synthesizing copper nanoparticles for biomedical and clinical applications. First draft submitted: 14 May 2018; Accepted for publication: 27 July 2018; Published online: 25 September 2018 Keywords: biocompatibility • Calotropis gigantea • CuO nanoparticles • HEK293 • human embryonic kidney cells line Recent advancement in nanotechnology has attracted the attention of nanotechnologist toward the exploration of metal and metal oxide nanoparticles usage. The metal oxide nanoparticles have gained this popularity because of their peculiar chemical and biological properties [1–4] and multiusage capabilities [5–9]. Among the different types of metal oxide nanoparticles, Copper oxide nanoparticles (CuO Nps) have gradually gained attention because of their low-cost production, high usage and multifunctional demand [10,11]. The usage of CuO Nps has been extended to various fields like the development of capacitor, conductor and biomedical applications like anticancerous therapeutics, antimicrobial agents [12,13]. The extensive demands and usage have led to the production of these nanoparticles in bulk quantity. With the increase in production and usage, a threat to the safety of ecosystem and consumers has also increased. Studies have reported the cytotoxic effect of copper nanoparticles due to their prolonged usage in different tissues and cells of the human consumers [14,15]. The cytotoxic effects and biocompatibility of copper nanoparticles have been referred to dependent on the concentration and their route of synthesis [16,17]. Synthesis of Copper nanoparticles have been reported mainly by three routes, physical methods like ball milling, chemical methods like sol-gel method and biological methods by different plants or animal extract [18–21]. Among these different routes, biological routes often called ‘Green Synthesis’ have been proved as one of the most biocompatible and ecofriendly methods for the CuO nanoparticles synthesis due to the usage of ecocompatible reagents for the synthesis process [22]. Nanomedicine (Lond.) (Epub ahead of print) ISSN 1743-5889 10.2217/nnm-2018-0175 C  2018 Future Medicine Ltd