The Mechanism of Cell Interaction and Response on Decellularized Human Amniotic Membrane: Implications in Wound...

ACELAGRAFT™ (Celgene Cellular Therapeutics, Cedar Knolls, NJ) was developed as a decellularized and dehydrated human amniotic membrane product (DDHAM). The product has demonstrated potential as a wound healing product with several ongoing preclinical and clinical studies in the area of acute and chronic ulcers. Although the mechanism of action of such a decellularized product has not been examined, a detailed study of the ability of fibroblasts to interact with DDHAM and subsequent cellular responses are presented. These studies indicate that the composition of DDHAM is that of an extracellular matrix (ECM)-like material with high collagen content, retaining key bioactive molecules, such as fibronectin, laminin, glycosaminoglycans (GAGs), and elastin. No cytokines or growth factors were identified as one might expect in a nondecellularized amniotic membrane product. Cell assays show that fibroblasts can recognize fibronectin in DDHAM and bind to it via typical integrin-fibronectin interactions. Fibroblasts secrete fibronectin and can actively assemble the soluble fibronectin into a complex extracellular matrix on DDHAM. Fibroblasts are also stimulated by DDHAM to secrete key proinflammatory(IL-1 and IL-6) and chemotactic cytokines or chemokines (proand IL-8) involved in regulating and enhancing wound repair processes. Microarray gene expression studies on fibroblasts bound to DDHAM show increased expression of key wound healing cytokines. Together, these studies provide insight into the mechanisms by which DDHAM may augment the wound healing process.