Authors: Jonathan Cooke & Matthew Dryden
Reactive oxygen species (ROS) play a pivotal role in the architecture of the normal wound-healing process . They function as messengers for effective operation of many immunocytes and non-lymphoid cells, which are involved in the tissue repair process, and appear to be important in coordinating the recruitment of lymphoid cells to the wound site and effective tissue repair.
ROS are also able to regulate the formation of blood vessels (angiogenesis) at the wound site and promote optimal perfusion of blood into the wound-healing area. ROS act in the host’s defense through phagocytes that induce a ROS burst onto the pathogens present in wounds, leading to their destruction, and during this period, excess ROS leakage into the surrounding environment has further bacteriostatic effects through their action on thiol groups on the surface of many microorganisms.
Sustained elevated levels of ROS, including hydrogen peroxide, are essential for successful appendage regeneration in tadpoles  and these regenerating tissues maintain a sustained level of intracellular H2O2 concentrations between 50 µM and 200 µM and for cell proliferation and tissue formation during embryogenesis [3,4].