Comparison of Amniotic Products in Full Thickness Rat Wound Model: Artacent Wound and Artacent AC

Introduction:<br/>It is well understood that human placental tissue contains a multitude of factors that play a part in the healing process [1]. Placental membrane is an attractive biomaterial for regenerative medicine applications due to its natural factors that aid in wound healing. angiogenetic and regenerative remodeling, as well as immunomodulation. However, the processing methods used to create final product have an impact on the growth factors that are retained [2]. A plethora of placental tissue processing methods has led to the creation of an array of placental product compositions and applications. Two products currently being used in the field are Artacent Wound®, a dehydrated dual layer amniotic graft and Artacent AC®, a tri-layer graft composed of a chorion sandwiched between two layers of amnion. In this study, we assessed these wound coverings in Sprague Dawley rats to elucidate the influence these scaffolds have on a healing wound. Additionally, this test is used to assess a modified version of Artacent AC to see if modifying certain tissue processing steps has implications on wound healing.<br/><br/>Methods:<br/>Two full thickness wounds were created on the dorsal side of each rat using a 2 cm x 2 cm square stencil and scalpel. Implant dimensions were approximately 2.5 x 2.5 cm. Samples were randomized into implantation sites across the animals. Implants were harvested at 7 days and grossly assessed for healed wound geometry, remodeling and re-epithelization. Implants were fixed in neutral buffered solution (NBS). Samples were stained with H&E and stained cross sections were evaluated for surface re-epithelialization, cellular infiltration, and remodeling. A numerical scoring system was utilized to quantify re-epithelialization and granulation tissue formation based on histological images.<br/><br/>Results:<br/>Initial and final wound measurements were used to calculate the percentage of wound closure for each test group. Re-epithelialization and granulation tissue formation ratings are used to calculate average values for each test group.<br/><br/>Discussion:<br/>No adverse effects were noted during this 7 day study. Partial wound healing is observed during the 7 day study, and healing is accelerated by the addition of a placental scaffold. Modified Artacent AC shows increased wound closure, equivalent re-epithelialization, and increased granulation tissue formation when compared to positive control (original Artacent AC).<br/><br/>Conclusion:<br/>No adverse effects were noted.<br/>The 2x2 Challenge Full Thickness Wound model in the rat shows partial healing at 7 days that is accelerated by the addition of a human placental membrane product to the wound bed.<br/>Modified version of Artacent AC shows improved wound healing when compared to original Artacent AC.<br/>- Increased wound closure<br/>- Equivalent re-epithelialization<br/>- Increased granulation tissue formation