Lyophilized Human Amnion Chorion Membrane (LHACM) Reduces Hypertrophic Scar Formation by Regulating TGFβ and Myofibroblasts.

BACKGROUND

We investigated whether a lyophilized human amnion chorion membrane (LHACM), with amnion, intermediate, and chorion layers, could alter or improve hypertrophic scarring.

METHODS

We utilized our previously published murine model to create human-like hypertrophic scars by applying mechanical tension over a healing HTS (Hypertrophic scar) wound. Treatment with subcutaneous LHACM allograft was administered prior to wound closure. Scars were explanted on day 19; imaged after Hematoxylin & Eosin, Masson's Trichrome, Picrosirius Red, and immunofluorescent staining; and analyzed with ImageJ, Matlab, CurveAlign, and CTfire.

RESULTS

Mechanical strain induced hypertrophic scarring, consistent with our previously validated model, and served as a basis for evaluating the effects of LHACM treatment1. Mechanical strain created wider, deeper, and denser scars compared to no strain controls. Picrosirius Red analysis showed that LHACM altered collagen fiber architecture, promoting fibers that were less aligned, straight, and wide than controls. Mechanical strain increased TGFβ and αSMA myofibroblast signaling, while treatment with LHACM reduced TGFβ and αSMA expression.

CONCLUSIONS

Subcutaneous treatment with LHACM significantly reduced gross and histological scar formation and improved collagen fiber arrangement by altering TGFβ and myofibroblast expression. Since available preventative options for HTS remain limited, commercially available LHACM could potentially be utilized clinically in high-tension wound sites to prevent and/or treat HTS.