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A facile and green route for the synthesis of copper nanoparticles (Cu NPs) has been achieved using green tea extract as a reducing, capping and stabilizing agent. UV-visible spectra gave surface plasmon resonance at 560 nm. The Cu NPs were characterized using various techniques. The size of the Cu NPs was about 20 nm. Antibacterial activity of biogenic Cu NPs were investigated against bacterial species Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa and Escherichia coli and compared based on diameter of inhibition zone in disc diffusion assay and minimum inhibitory concentration and minimum bactericidal concentration of NPs dispersed in liquid cultures. The NPs showed better inhibitory activity against Gram-positive bacteria (S. aureus and B. subtilis) compared to Gram-negative bacteria. Toxicity of the NPs was evaluated against animal cell line using MTT assay.

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Epidermal growth factor receptor (EGFR), a transmembrane glycoprotein, is overexpressed in many cancers such as head-neck, breast, prostate, and skin cancers for this reason it is a good target in cancer therapy and diagnosis. In nanobody-based cancer diagnosis and treatment, nanobodies with high affinity toward receptor (e.g. EGFR) results in effective treatment or diagnosis of cancer. In this regard, the main aim of this study is to develop a method based on molecular dynamic (MD) simulations for designing of 7D12 based nanobody with high affinity compared with wild-type nanobody. By surveying electrostatic and desolvation interactions between different residues of 7D12 and EGFR, the critical residues of 7D12 that play the main role in the binding of 7D12 to EGFR were elucidated and based on these residues, five logical variants were designed. Following the 50 ns MD simulations, pull and umbrella sampling simulation were performed for 7D12 and all its variants in complex with EGFR. Binding free energy of 7D12 (and all its variants) with EGFR was obtained by weighted histogram analysis method. According to binding free energy results, GLY101 to GLU mutation showed the highest binding affinity but this variant is unstable after 50 ns MD simulations. ALA100 to GLU mutation shows suitable binding enhancement with acceptable structural stability. Suitable position and orientation of GLU in residue 100 of 7D12 against related amino acids of EGFR formed some extra hydrogen and electrostatic interactions which resulted in binding enhancement.