Human Amniotic Membrane (HAM)

Human Amniotic Membrane (HAM) is a multi-component biological tissue derived from the innermost layer of the placenta, widely utilized in regenerative medicine for its unique bioactive and non-immunogenic properties. Rather than acting on a single molecular target, HAM functions through a diverse array of growth factors, cytokines, and extracellular matrix components that collectively promote rapid wound healing and tissue remodeling (Niknejad et al., 2008). It is particularly noted for its expression of Human Leukocyte Antigen G (HLA-G), which provides potent immunomodulatory effects by suppressing maternal-fetal immune rejection, a property leveraged clinically to reduce inflammation and avoid graft-versus-host responses (Rouas-Freiss et al., 1997). Additionally, the membrane contains innate antimicrobial peptides such as defensins and elafin, which protect the tissue from infection during the healing process (King et al., 2007). Clinically, HAM is most frequently applied as a biological dressing for chronic, non-healing wounds like diabetic foot ulcers and in ophthalmic surgeries to treat corneal defects and persistent epithelial erosions (Fetterolf et al., 2012). Its broad-spectrum mechanism of action makes it a superior alternative to single-target therapies in complex pathological environments where multiple cellular pathways are dysregulated.

Other names

AmnionPlacental membraneDehydrated Human Amnion/Chorion MembranedHACMAmniotic tissueAmniotic fluid-derived factors

The therapeutic acts as a bioactive scaffold that releases a complex secretome of growth factors (such as EGF, TGF-beta, and PDGF) to stimulate cell proliferation and migration. It provides structural extracellular matrix components (collagen, laminin) for cell attachment, while protease inhibitors like TIMPs prevent excessive tissue degradation. Furthermore, it exerts antimicrobial effects through defensins and achieves immunomodulation via the expression of HLA-G, which inhibits T-cell and Natural Killer cell activity to prevent graft rejection and reduce inflammation.