Purion Processed Placental Biologics Retain Critical Activity for Healing Fibrotic Wounds

Introduction: Fibrosis is characterized by the buildup of activated fibroblasts and excessive deposition of extracellular matrix proteins, particularly type I collagen. The prolonged presence of myofibroblasts is responsible for the excessive accumulation of type 1 collagen and increased contractile capacity of cells that leads to impaired tissue architecture and function. Regulation of the pathways associated with collagen production is a promising therapeutic concept to prevent excessive scar formation. Previous observations demonstrated that dehydrated human amnion/chorion membrane (dHACM*) modulated fibrotic pathways through the regulation of the TGFβ pathway and reduced myofibroblast contraction.

This study further investigates the effect micronized dHACM** has on the regulation of fibrotic pathways and collagen production.

Methods: In vitro, adult human dermal fibroblasts were stimulated with TGFβ1, triggering myofibroblast-like characteristics. After 24 hours, µdHACM extract was added in the continued presence of TGFβ1. Following incubation for an additional 24 hours, the cells were analyzed for markers associated with a myofibroblast phenotype, and type 1 collagen production by quantitative PCR, western blot and immunofluorescence analysis. Functional readout included analysis of collagen matrix contraction. Results: Human dermal fibroblasts challenged with TGFβ1 exhibited an increased expression of key genes associated with fibrosis, differentiation of myofibroblasts and production of collagen, confirming the induction of a fibrotic environment in vitro. Subsequent treatment with micronized dHACM lead to a reduction in the expression of known fibrotic and extracellular matrix genes. Cell lysates analyzed by Western blot, demonstrated inhibition of SMAD2 phosphorylation, a key messenger in the TGFβ signaling pathway. Additionally, micronized dHACM led to reductions in alpha smooth muscle actin (αSMA), a myofibroblast marker, and type 1 collagen. The effects on αSMA and type 1 collagen were confirmed by immunofluorescence microscopy. Reduction in myofibroblasts contributed to the reduced contractile capacity of fibroblasts in an ex vivo cell contraction assay.

Discussion: These data further demonstrate that Purion processed placental biologics retain their native regulatory and biological activity. Additionally, these data support the potential role of micronized dHACM as a regulator of fibrosis and support a mechanism by which treatment may have utility in scar reduction.