Stabilization of growth factors relevant to wound healing by a plant cell wall biomaterial

Stabilization of growth factors in a wound environment is critical to the wound healing process. Here we report on the stabilization of key growth factors by a unique plant cell wall biomaterial. MicroSheets are clear cell wall fragments isolated from the non-living water storage cells in the pulp or inner gel of Aloe vera L., which has widely been used for wound healing. It was found that MicroSheets bind to a subset of heparin binding growth factors including basic fibroblast growth factor (bFGF) and keratinocyte growth factor (KGF), two key growth factors in the wound healing process. The binding of bFGF and KGF to MicroSheets was inhibited by heparin and also by a pectic substance isolated from the MicroSheets, indicating that the binding was mediated by this pectic component of the MicroSheet. The binding protected the growth factors against protease digestion. Furthermore, the protective effect was also demonstrated with KGF against digestion by wound fluids and by measuring the biological activity. Thus, these results showed that MicroSheets can stabilize certain critical growth factors in wounds and thereby promote the healing process. Incorporation of a material like MicroSheets provides an important functional element in wound dressings, i.e., growth factor stabilization.