Enhanced Skin Regeneration Using a Novel Amniotic-derived Tissue Graft.

BACKGROUND: Chronic and recalcitrant wounds present a significant therapeutic challenge. Amniotic tissues contain many regenerative cytokines, growth factors, and extracellular matrix molecules including proteoglycans, hyaluronic acid, and collagens I, III, and IV. Dehydrated amnion/chorion grafts are currently used to treat a variety of wounds such as diabetic foot ulcers and burns.

OBJECTIVE: The investigators hypothesized that processing methodologies, dehydration, and hypothermic processing and storage of amniotic tissues would affect overall quality of wound healing; they compared dehydrated amnion/chorion (dHACM) grafts to a novel hypothermically stored amniotic membrane (HSAM) graft in a full-thickness rat wound model.

MATERIALS AND METHODS: Sprague-Dawley rats were anesthetized and prepped for surgery; four 1.5-cm diameter full-thickness wounds were created and treated with either: (1) dHACM, (2) dHACM meshed, (3) HSAM, or (4) wound left ungrafted (sham). After 9 or 21 days, wounds and surrounding areas were collected and stained with hematoxylin and eosin. Blinded quantitative analysis of quality of wound healing was completed by evaluating hair follicle/gland formation, dense/scar-like matrix, and basket-weave matrix.

RESULTS: At varying time points following placement of the grafts into full-thickness defects, the authors found that all amniotic-derived tissue grafts appeared to stimulate improved healing over sham wounds, evidenced by more normal-appearing dermal matrix architecture, epidermal structure, and maturity. In addition, the HSAM grafts promoted greater tissue regeneration than the dHACM meshed grafts, as measured by the presence of basket-weave collagen matrix and formation of follicles and glands.

CONCLUSIONS: In sum, this study builds on the amassing literature supporting amniotic tissues for wound repair and demonstrates the importance of tissue processing on the quality of wound healing.