Silver nanoparticles have a wide range of research, industrial and biomedical applications that make it essential to develop a low cost and eco-friendly approach with scaling up potential. Green synthesis of nanoparticles through bio-reactions leads to a reduction of silver ions to particles could be an acceptable selection using no additional reducing chemicals. Moreover, the simplicity of scale-up processes of the method makes it more efficient than chemical and physical synthesis methods. In this study, Datura stramonium leaf extract and sodium citrate were used as biological and chemical reducing and stabilizing agents to make silver nanoparticles. The main goal is to comprise properties and evaluate antibacterial activity of nanoparticles synthesized through two approaches. Size and morphology compared between the two types of the synthesized nanoparticle by UV-Visible spectroscopy, DLS, AFM, TEM and their antibacterial effects were evaluated through growth inhibition MIC and MBC methods. The results showed narrow size range, spherical shape, high anti-oxidant, antibacterial and DNA cleavage activities of green synthesized silver nanoparticles comparing to less average size, wider range of nanoparticle size, no anti-oxidant activity and less antibacterial and DNA cleavage activities of chemically synthesized nanoparticles. The green synthesized silver nanoparticles had more desirable characteristics and biological activities compared to chemically synthesized nanoparticles. For instance, the green nanoparticles showed narrow size range, spherical shape, high anti-oxidant, antibacterial and DNA cleavage activities versus the chemically synthesized which had less average size, higher range of nanoparticles size, no anti-oxidant activity and less antibacterial and DNA cleavage activities.

Described here is a simplified method for fabrication of DNA nanotubes using a minimum numbers of staple oligomers for DNA origami. For this purpose, the cylindrical nanotemplates with two sticky ends have been designed using caDNAno software. Then, the nanostructures were shaped in an optimized experimental condition via an origami-based self-assembly reaction. Finally, the produced nanostructures were joined together through their sticky ends using a ligase enzyme. Transmission electron microscope confirmed fabrication of these elongated nanotubes. In addition, high-resolution microscopy of DNA nanotubes by scanning tunnelling microscope indicated efficient attachments of the primarily DNA nanostructures via their sticky ends. The results demonstrated that a ligase treatment of cylindrical DNA nanostructures with the sticky ends made DNA nanotubes with standard shapes using minimum numbers of staples.

One of the main challenges in wound healing is the wound infection due to various causes, of which moisture is the most important reason. Owing to this fact, wound dressings that can collect wound moisture in addition to showing antibacterial properties have provided an important basis for wound healing research. In this study, gelatin and poly lactic acid (PLA) polymers were used in a wound dressing textile to provide gelation and structure strength properties, respectively. Meanwhile, silver nanoparticles (SNPs) synthesized through the green method were integrated into these fibers to provide the formed textile with antibacterial properties. Nanoparticles were made using donkey dung extract, and nanofibers were produced by the solution blow spinning method which has high production efficiency and low energy consumption among spinning methods. The produced nanoparticles were characterized and evaluated by UV-Vis, DLS, XRD, and FTIR methods, and the production of silver nanoparticles that were coated with metabolites in the extract was proven. In addition, the morphology and diameter of the resulted fibers and presence of nanoparticles were confirmed by the SEM method. The size and size distribution of the synthesized fibers were determined through analyzing SEM results. Gelatin nanofibers demonstrated a mean size of 743 nm before and 773 nm after nanoparticle coating. PLA nanofibers demonstrated a mean size of 57 nm before and 182 nm after nanoparticle coating. Finally, 335 nm was the mean diameter size of gelatin/PLA/SNPs nanofibers. Also, the textiles synthesized by PLA and gelatin which contained silver nanoparticles showed higher antibacterial activity against both gram-positive and gram-negative species compared to PLA and gelatin tissues without nanoparticles. Cytotoxicity test on L929 cells showed that silver nanoparticles incorporated textiles of PLA and gelatin show a very low level and non-significant toxicity compared to the free particles.