Biophysical Characterization of a Novel Tri-Layer Placental Allograft Membrane

Abstract

Objective: Placental tissues, including membranes composed of amnion and chorion, are promising options for the treatment of chronic wounds. Amnion and chorion contain multiple extracellular matrix (ECM) proteins and a multitude of growth factors and cytokines that, when used clinically, assist in the progression of difficult to heal wounds through restoration of a normal healing process. The objective of this study was to characterize the in vitro physical and biological properties of a dehydrated tri-layer placental allograft membrane (TPAM) consisting of a chorion layer sandwiched between two layers of amnion. Approach: Mechanical properties were evaluated by mechanical strength and enzyme degradation assays. The ECM composition of TPAM membranes was evaluated by histological staining while growth factors and cytokine presence was evaluated by a multiplex enzyme-linked immunosorbent assay. Proliferation, migration, and ECM secretion assays were performed with fibroblasts. Immunomodulatory properties were assessed by a pro-inflammatory cytokine reduction assay while the macrophage phenotype was determined by quantifying the ratio of M1 versus M2 secreted factors. Results: The unique three-layer construction improves mechanical handling properties over single-and bi-layer membranes. Results demonstrate that TPAM is rich in ECM proteins, growth factors, cytokines, and tissue inhibitors of metalloproteinases, and favorably influences fibroblast migration, proliferation, and ECM secretion when compared to negative controls. Furthermore, after processing and preservation, these membranes maintain their intrinsic immunomodulatory properties with the ability to suppress pro-inflammatory processes and modulate the M1 and M2 macrophage phenotype toward a pro-regenerative profile when compared to a negative control. Innovation: This is the first study to characterize both the biophysical and biological properties of a tri-layer placental membrane. Conclusion: This work demonstrates that TPAM has improved handling characteristics over single-and bi-layer membranes, stimulates pro-healing cellular responses, and advantageously modulates inflammatory responses, altogether making this scaffold a promising option for treating wounds, especially those that are complex or difficult to heal.

Characterization of a full‐thickness decellularized and lyophilized human placental membrane for clinical applications

“…22 To our knowledge, suture retention has not been reported for other commercially-available placental membrane grafts, which may be related to their comparatively lower overall failure loads (ie, 5-to 42-times lower than FT-DPM). 21 While our suture retention tests did not include all suture diameters in common clinical use (ie, 2-0 to 6-0), it is reasonable to infer that smaller diameters would yield lower retention. Inclusion of the fully-intact trophoblast layer provides for a more robust strength profile that likely contributed to successful cannula pass-through and layer retention following in vivo implantation results, suggesting that FT-DPM may provide a substantial protective covering for soft-tissue repairs.…”

From ancient Egypt to the dermatologic office: An overview of skin substitutes and modern‐day applications in dermatologic surgery

“…Monolayer HAM consists of only amnion while bilayer HAM consists of amnion and chorion. The newer tri-layered allograft membrane consists of a chorion layer sandwiched between two layers of amnion, 11 which has the added benefit of improved mechanical handling properties over its single and bi-layered counterparts and stimulates pro-healing cellular responses while dampening proinflammatory responses. 11 The use of placental tissue as an allograft during a skin transplantation was first documented in 1910.…”

“… 9 Placental tissue effectively supports wound healing through a rich ECM‐containing proteins (collagens I, III, IV, VI, proteoglycans, glycoproteins), growth factors, cytokines, and viable endogenous cells and mesenchymal stem cells that help facilitate the wound‐healing process. 10 , 11 Further, these various components impact cell differentiation, hormone/protein production, and basement membrane remodeling. 10 Such properties are beneficial for the treatment of complex, chronic, nonhealing burns, ulcers, and wounds.…”

“…The newer tri‐layered allograft membrane consists of a chorion layer sandwiched between two layers of amnion, 11 which has the added benefit of improved mechanical handling properties over its single and bi‐layered counterparts and stimulates pro‐healing cellular responses while dampening pro‐inflammatory responses. 11 …”

“…The placenta is composed of three layers; the innermost amniotic layer surrounds the embryo/fetus and consists of a single‐celled epithelial layer firmly fixed to a deeper collagen containing mesodermal layer, the middle allantois layer is rich in blood supply, and the outermost chorion which comes into contact with the endometrium and consists of trophoblastic and mesenchymal tissue 9 . Placental tissue effectively supports wound healing through a rich ECM‐containing proteins (collagens I, III, IV, VI, proteoglycans, glycoproteins), growth factors, cytokines, and viable endogenous cells and mesenchymal stem cells that help facilitate the wound‐healing process 10,11 . Further, these various components impact cell differentiation, hormone/protein production, and basement membrane remodeling 10 .…”