Characterization of Minimally Processed Placental Umbilical Cord Membranes Developed for use as a Surgical Implant Around Peripheral Nerve
Curt Deister, PhD; Stefanie Villender, PhD; Anne Engemann, PhD, Brian Romot, MS; Erick DeVinney, BS
AxoGen, Alachua, FL
Introduction: Inflammation is a normal component of wound healing and can result in increased scar formation and adhesions. Placental tissues have been studied as possible mediators of inflammation but their use as an implant for internal surgical applications has suffered from inherent limitations in mechanical properties. This work describes minimally processed placental membranes, isolated from human umbilical cord membrane that retain the beneficial placental properties of the tissue, with its known potential for reducing inflammation and adhesion formation. Processed umbilical cord membrane provides ideal mechanical properties appropriate for a surgical implant while remaining in the wound throughout the wound healing cascade.
Methods: Proteins were quantified using Milliplex« kits and analyzed using a Luminex 200TM. Resorption rate was determined by subcutaneous implant in a rat model followed by macroscopic and histological evaluation of resorption at 16 weeks. Thickness was determined by use of a push-gauge as the average of 3 sites along the graft. Tensile strength was measured at a rate of 25.4 mm/min. Suture retention strength was measured with 6-0 suture, bite depth of 3-6mm and a rate of 25.4mm/min.
Results: Protein quantification included identification of 28 proteins detected at either higher (13), similar (5) or lower (10) levels compared to unprocessed controls. Proteins found at relatively high levels included several interleukins, TIMP-4 and several growth factors including EGF, FGF, PDGF, VEGF and TGF-?3. Macroscopic and histologic evaluation methods determined that approximately 75% of the implant was resorbed at 16 weeks. Average thickness of the processed umbilical cord membrane was 176Ám compared to <25Ám for placental amnion. Mean tensile strength of processed umbilical cord membrane was 12.3N and the mean force required for suture pull out was 1.47N.
Conclusions: The results of these studies demonstrate that minimally processed umbilical cord membrane retains the inherent properties of native tissue, when implanted remains present for at least 16 weeks, is approximately 8 times thicker than placental amnion, and possesses sufficient mechanical properties to allow normal handling and use in the surgical environment.
Back to 2018 ePosters