The Use Of Xenogeneic EDC Cross-linked Acellular Tendon Of Mini-pig Inbred-lines As A Biomaterial For Achilles Tendon Repair In A Rabbit Model

Object:Ideal tendon repair materials combine minimal donor-site morbidity and ready availability with excellent healing and postoperative function. Bioengineered EDC cross-linked acellular tendon of Banna mini-pig inbred-lines was compared with tendon autografts as a potential human flexor tendon graft substitute.To investigate the effect of substitution of 1-ethyl-3-3-dimethy laminopropyl arbodiimide hydrochloride(EDC) cross-linked acellular tendon of Banna mini-pig inbred-lines for rabbit Achiles tendon, then evaluate the feasibility and validity of porcine-derived xenogeneic graft.Methods:(1) Extensor digitorum tendons harvested from Banna mini-pig inbred-lines were divided into fresh tendon group,deep-freezed tendon group,simply decellularized tendon group and EDC cross-linked acellular tendon group.The histological and structural changes treated by different methods were obserbved via HE staining and scaning electron microscopy and compared between groups to evaluated the histological and structural influence of EDC cross-linking on tendons; 1-ethyl-3-3-dimethy laminopropyl arbodiimide hydrochloride EDC cross-linked acellular tendon of Banna mini-pig inbred-lines was taken out and processed. (2)40 Rabbits were divided into two groups randomly, group A was xenograft transplanting group,group B was autograft transplanting group and were used as controls. After transplanting, followed by unrestricted motion. White blood cell (WBC) differential count and CRP count at 3 days preoperation,3 days postoperation,and 1 week and 2 weeks postoperation. Animals were killed at 1,4,8and 12weeks. Specimens were analyzed for hydroxyproline content (absorption spectroscopy) and tensile strength. Hematoxylineosin and Movat-stained sections of the central graft and distal repair site were semiquantitatively scored for total cellularity, inflammatory cell content, foreign-body reaction,vascularity, mature collagen content, and new collagen deposition. histological observation, immunology and biomechanics were performed regularly.Results:There were little imflammation, well healing and normal phalanx flextion postoperation. There was no proof of immigration of lymphoid cell. The collagen fiberswere connected each other in suture area, thus suggusting EDC cross-linked acellular tendon of Banna mini-pig inbred-lines was ingrowth and connected with normal tendon. There was no difference in bioscience between two groups eight weeks postoperation.Conclutions:The EDC cross-linked acellular tendon of Banna mini-pig inbred-lines,with good histocompatibility, faint antigenicity and adequate bio-mechanical strength after xenografts.