Moist Wound Healing The moist environment provided by covering a wound (left) allows the epidermal cells to move easily across the wound surface, healing the wound. In a dry environment (right), the epidermal cells must tunnel down to a moist level and secrete enzymes to lift the scab away from thw wound surfae before the cells can migrate and begin to allow healing to occur.
10 to the 5 th colonization has no confirmed connection to the threshold or degree of immune response or to healing
Infection diagnosis often a retrospective diagnosis
Evidance supports the fact that delayed healing in a chronic wound that has no signs of clinical infection, suggestive of critical colonization, is directly related to microbial bioburden, notably nonhemolytic strep and anaerobes.
Where wounds are static or exudate levels high, critical colonization or infection should be suspected
“ use of topical antibiotics is not justified for the routine treatment of colonized or infected wounds”
Can provoke delayed hypersensitivity response
Select for resistant bacterial strains
“ routine use of topical antibiotics in the management of clinically infected leg ulcers has been shown to be of no benefit and some evidance shows it may be harmful because it encourages colonization by resistant organisms”
Povidine- iodine, chlorhexidine, hydrogen peroxide, and 0.25% acetic acid have been shown to interfere with fibroblast formation and epithelial growth
The selected use of topical antiseptics should be reserved for wounds that do not have the ability to heal, or for the time – limited use in wounds where bacterial burden is more important than cellular toxicity.
Colonized wounds are present for longer, are larger and have significantly delayed healing time when compared with ulcers where n bacterial growth is found
“ early and appropriate intervention using silver- or iodine- containing dressings in particular can avoid progression to critical colonization and infection, thus potentially improving healing rates and reducing the risk of cross contamination”
Smartness – cells are able to adapt to their micro environment
Knowledge base – cells may bypass our lack of knowledge about what is required in specific situations
Commercially available – cells are readily available as primary cultures, off the shelf products
Manipulation – cells can be genetically manipulated
Apligraf ® — Manufacturing Process Human Dermal Fibroblasts Connective Tissue Proteins Dermal Matrix Human Epidermal Keratinocytes Apligraf Data on file, Organogenesis Inc., Canton, MA.
Parentau NL, et al. J Cell Biochem . 1991;45:245-251.
Apligraf ® Why Fibroblasts and Keratinocytes?
Components of Wound Healing Injury Hours Days Weeks Coagulation Process Inflammatory Process Migratory/ Proliferative Process Remodeling Process Platelets Platelets Macrophages Neutrophils Fibroblasts Cell Types Involved Kane DP, Krasner D. Inc. Chronic Wound Care . 2nd ed. Health Management Publications Inc; 1997:1-4. Macrophages Lymphocytes Fibroblasts Epithelial cells Endothelial cells