Tissue morphology study: van gieson staining in healing process of full thickness wound animal model / Azila Ali

This study was done to investigate the histology property of the wounded skin during the process of initially wounding until day 28 and to study the extent of reepithelialization of wounds which is important because it is a process that create a barrier between the inner organs and the surrounding environment. Full thickness bum wound was produced at the dorsal part of Sprague Dawley rats. The macroscopic image of tissue morphology was captured and the skin samples were harvested on 0, 2, 7, 14, 21 and 28 days post injury. Subsequently, the samples were fixed in 10% buffered formalin solution prior to staining with Van Gieson solution. The histology study was done to bring out the different structures of the tissue, especially collagen and elastin fibers, by staining the cells in contrasting colours. Van Gieson solution stained collagen fibers in red and elastic fibers in black. For the first two days, it was observed that the histologic findings showed a complete destruction of both of dermis and epidermis. By day 7, the inflammation phase was almost absent as proliferation phase occurred where the injured tissue was covered by thick scab. At day 14, injured tissue undergo rapid reepithelialization process. The presence of homogenous, closely packed and interwoven bundles of red-stained collagen fibers and black-stained elastic fibers in the wounded area of the rat were observed at day 21. By day 28, the wound histology showed an incomplete tissue re­ epithelialization with the presence of modeled dense collagen mesh and a moderate fibroblastic proliferation. The time required for complete reepithelialization of the injured tissue of full thickness wound without applying a specific therapeutic agents, may take 3 to 6 weeks or even more and might leave a scar tissue due to the excess collagen fibers formation.