Especially in the biological and pharmaceutical sectors, nanostructure materials are attracting a great deal of attention because of their potential for achieving specific processes and selectivity.38 Decreasing the dimension of nanoparticles has a pronounced effect on their physical properties, which significantly differ find more from those of the bulk material. Moreover, there are several reasons for the use of silver nanoparticles in nanotechnology as well as in the medical and pharmaceutical fields, especially in wound healing. The properties that aid in wound healing are listed here and in Table 2. (1) Silver compounds have been used in medicine throughout the history of civilization.39,

40, 41, 42 and 43 (2) It is easy to synthesize silver nanoparticles in large scale by several simple, inexpensive, safe, and reliable ways, including wet chemical, physical and biological methods.38 (3) They can be synthesized in sizes from 2 to 500 nm by changing the reaction parameters. (4) They can be easily synthesized in different

shapes (spheres, rods, tubes, wires, ribbons, plates, Belnacasan cubes, hexagons, triangles) by the selection of templates and reaction conditions.38 (5) Because of the presence of a negative charge on their surface, they are highly reactive, which makes their surfaces modifiable by means of several biomolecules, a factor that aids in drug delivery.38 Because of the strong interaction

between the silver surface and molecules containing thiol or amine (organic molecules, DNA, proteins, enzymes, etc), the surface of silver nanoparticles can be easily modified.38 (6) Silver nanoparticles exhibit antibacterial effects against a large number of bacterial species.44 The antibacterial mechanism has not been fully elucidated, but observations from recent studies shed light on the Vasopressin Receptor interactions involved.45 It is believed that silver ions interact with 3 main components of the bacterial cell to produce a bactericidal effect: the peptidoglycan cell wall and the plasma membrane, bacterial (cytoplasmic) DNA46 and 47 and bacterial proteins,46 and especially enzymes involved in vital cellular processes such as the electron transport chain. (7) Bacterial resistance to elemental silver is extremely rare,45 emphasizing the presence of multiple bactericidal mechanisms acting in synergy. (8) Silver nanoparticles can be easily incorporated in cotton fabric and dressings and have significantly decreased wound-healing time by an average of 3.35 days and increased bacterial clearance from infected wounds, with no adverse effects observed for the dressing.48, 49, 50, 51, 52, 53, 54 and 55 (9) Anti-inflammatory properties of silver nanoparticles also promote wound healing by reducing cytokine release,56 decreasing lymphocyte and mast cell infiltration.