Determination of Endogenous Growth Factors in Human Wound Fluid: Temporal Presence and Profiles of Secretion

Abstract

Growth factors are important substances in the central control of wound healing during the exudative phase. Although these peptides have been applied frequently to chronic wounds in clinical studies, little is known about the naturally occurring levels at the wound site in correlation to healing in superficial wounds. We have therefore investigated the presence of these cytokines in partial thickness wounds. In 16 patients undergoing reconstructive surgery, split-thickness skin wounds were enclosed in cutaneous vinyl chambers filled with 2.5 ml of saline. Chambers placed over unwounded skin served as controls. After 24 hours, the accumulated wound fluid was harvested and replaced by 2.5 ml of saline until the wounds were healed. Wound fluid was centrifuged, aliquoted, and frozen at -70 degrees C. Samples were analyzed for protein and growth factors (insulin-like growth factor-1, epidermal growth factor, basic fibroblast growth factor, platelet-derived growth factor-AB, interleukin-1alpha, and transforming growth factor-beta1 and -beta2) and insulin-like growth factor-binding proteins 1 and 3 using a monoclonal Sandwich enzyme-linked immunosorbent assay and radioimmunoassay. All wounds healed in the liquid environment within 7 days (macroscopically) and 11 days (barrier function), respectively. In wound fluid, protein concentrations dropped from 5 mg/ml on day 1 to a baseline of 0.1 mg (unwounded skin), indicating a return of the barrier function. All growth factors could be measured already after 24 hours postwounding. However, the concentrations measured varied from 10 to more than 10,000 pg/ml between the different factors. The highest range was found for insulin-like growth factor-1 (21,000 to 41,000 pg/ml), the lowest for epidermal growth factor (3 to 63 and 3 to 88 pg/ml, respectively). Two different patterns of kinetics were distinguished: (1) a high initial peak decreasing to baseline values or below serum levels by the time of healing (insulin-like growth factor-1, insulin-like growth factor binding protein-1, -3, basic fibroblast growth factor, epidermal growth factor, platelet-derived growth factor-AB, transforming growth factor-beta1) and (2) a low initial concentration followed by an increase to a maximum at the time of epithelialization (interleukin-1alpha, transforming growth factor-beta2). Comparing the growth factor levels measured to serum baseline values, it was found that four of the growth factors appeared in wound fluid at above serum concentrations (interleukin-1alpha, transforming growth factor-beta2, basic fibroblast growth factor, epidermal growth factor); the other factors never reached serum values in wound fluid (insulin-like growth factor, transforming growth factor-beta1, platelet-derived growth factor-AB). It is concluded that the different profiles of secretion might reflect different functions of polypeptide growth factors such as stimulation of epithelialization (epidermal growth factor, insulin-like growth factor-1), matrix synthesis (transforming growth factor-beta), and inflam...

Full-Thickness Skin Wound Healing Using Human Placenta-Derived Extracellular Matrix Containing Bioactive Molecules

“…[28][29][30] The growth factors present in wound fluid during the healing of full-thickness cutaneous wounds act at different levels based on the time of healing; for example, TGF-b (32-1273 pg/ mL), PDGF (63-1874 pg/mL), bFGF (63-512 pg/mL), VEGF (1209-1590 pg/mL), and EGF (15-111 pg/mL). 31,32 Preservation of the native ultrastructure and composition during the extraction and decellularization of the ECM from tissue is highly desirable. Similar to the retained ECM proteins, the retention of various growth factors in the decellularized ECM is an important aspect of its biological activity as an implant or scaffold material for skin tissue engineering.…”

Regulation of Wound Healing by Growth Factors and Cytokines

“…This combination of different cellular sources and temporary storage ensures a continuous supply of TGF-␤ throughout the repair process (228). Several publications report on the presence of TGF-␤s in wound fluid of different species (27,35,204,281). Furthermore, expression of all three isoforms was detected in many different cell types during repair, with each isoform having a characteristic distribution in the wound tissue (91,141,157,238,270,271).…”

Intradermal adipocytes mediate fibroblast recruitment during skin wound healing

“…PDGF has many important roles in skin wound healing and serves as a chemotactic agent for neutrophils, macrophages and fibroblasts (Heldin and Westermark, 1999). The primary source of PDGF in healing skin wounds is thought to be platelets (Vogt et al, 1998), but adipocytes may contribute to later PDGF expression in skin wounds. The role of BMPs in skin wounding has not been explored extensively.…”