Patch tracheoplasty in body tissue engineering using collagenous connective tissue membranes (biosheets)

BackgroundCollagenous connective tissue membranes (biosheets) are useful for engineering cardiovascular tissue in tissue engineering. The aim was to evaluate the use of biosheets as a potential tracheal substitute material in vivo in a rabbit model.MethodsGroup 1: Rectangular-shaped Gore-Tex (4 × 7 mm) was implanted into a 3 × 6 mm defect created in the midventral portion of the cervical trachea. Group 2: Rectangular-shaped dermis was implanted into a tracheotomy of similar size. Group 3: Biosheets were prepared by embedding silicone moulds in dorsal subcutaneous pouches in rabbits for 1 month.Rectangular-shaped biosheets were implanted into a tracheotomy of similar size in an autologous fashion. All groups (each containing 10 animals) were sacrificed 4 weeks after implantation.Main ResultsAll materials maintained airway structure for up to 4 weeks after implantation. Regenerative cartilage in implanted Biosheets in group 3 was confirmed by histological analysis. Tracheal epithelial regeneration occurred in the internal lumen of group 3. There were significant differences in the amounts of collagen type II and glycosaminoglycan between group 3 and group 1 or 2.ConclusionWe confirm that cartilage can self-regenerate onto an airway patch using Biosheets.