GROWTH-FACTORS IN WOUND-HEALING

Normal wound healing requires the coordinated completion of a variety of cellular activities. The cellular activities involved in normal healing include phagocytosis, chemotaxis, mitogenesis, collagen synthesis, and the synthesis of other matrix components. After a wound is created, phagocytosis of bacteria and damaged tissue is a necessary prerequisite to most other healing processes. Neutrophils and macrophages are the primary phagocytic cells. Chemotaxis is the migration of cells against a gradient. Chemotactic agents for inflammatory cells, fibroblasts, and cells involved in angiogenesis contribute to the healing process. Mitogenesis-stimulating agents cause cells required for healing to divide. Mitogenesis generates more fibroblasts, epithelial cells, and angiogenic cells to carry out the healing process. New collagen and ground substance are required to give the healing wound strength and structure, and the synthesis of these proteins and glycoproteins, primarily by fibroblasts, is another critical component of the healing process. Wound contraction and scar remodeling are other major aspects of healing. These processes are most likely not purely cellular activities, though cells are required for wound contraction and scar remodeling to occur. All of these processes must be accomplished for a wound to heal. © 1994.