Purpose: The author hypothesizes that exogenously injected BMP, which is mixed with fibrin glue, can accelerate the healing of a bone-tendon junction injury and increase its holding strength during the early regeneration period. Materials and Methods: A direct injury model of the bone-tendon junction was made using the Achilles tendon-calcaneus bone of 54 rabbits: and the transected Achilles tendon was repaired to its original insertion site using the Krackow method. In Group 1, no additional manipulation was performed. In Group 2, only fibrin glue was injected into the junction between the Achilles tendon and the calcaneus in order to exclude the effect of the fibrin glue. In Group 3, BMP-2 incorporated into the fibrin glue was injected into the junction. The results were evaluated by histological analysis and biomechanical tests at 2, 4, and 8 weeks after surgery. The Kruskal-Wallis test was used for a statistical evaluation. Results: Histological analysis revealed the early appearance of fibrocartilage at 2 weeks in Group 3: the area of the fibrocartilage expanded with time. The biomechanical tests showed significant differences in the maximum stress between Groups 1 and 3, and between Groups 2 and 3, at 2, 4, and 8 weeks. 74.4% of the normal maximum stress was recovered at 8 weeks in Group 3. Conclusion: The combined use of BMP-2 and the fibrin glue can accelerate the healing of an injury of the bone-tendon junction.
Achilles Tendon ; Calcaneus ; Fibrin Tissue Adhesive* ; Fibrin* ; Fibrocartilage ; Rabbits ; Regeneration

PURPOSE: The objective of this study is to develop a tissue-engineered vascular graft using autologous bone marrow-derived cells (BMCs) and biodegradable polymer scaffold. METHOD: Autologous canine BMCs were isolated from bone marrow aspirate and cultured. A tubular scaffold was fabricated by immersing polyglycolic acid (PGA) sheet in poly (glycolide-co-caprolactone) (PGCL) solution and wrapping it around a cylindrical mold. The expanded BMCs were seeded onto the PGA/PGCL tubular scaffold (internal diameter: 7 mm, length: 35 mm) and further cultured in vitro for 1 week. The graft was anastomosed to the abdominal artery in a canine model. One week after implantation, the retrieved graft was investigated by histological and immunohistochemical analyses. RESULT: Cultured BMCs differentiated into endothelial-like and smooth muscle-like cells. The PGA tubular scaffold reinforced with PGCL was successfully implanted in an animal model without graft rupture. The vascular graft engineered with BMCs was occluded at 1 week after implantation due to thrombus formation. Histological and immunohistochemical analyses of the retrieved graft revealed that extracellular matrix proteins such as smooth muscle alpha-actin, smooth muscle myosin heavy chain and collagen were produced partially in the graft media. CoNCLUSION: The tissue-engineered vascular graft developed in this study led to graft failure due to early occlusion. Nevertheless, it is confirmed that the PGA/PGCL scaffold has microstructures appropriate for cell proliferation and good mechanical properties. This result suggests the possibile application of this scaffold as a material for engineering of diseased vascular tissues.
Actins ; Arteries ; Blood Vessel Prosthesis* ; Bone Marrow ; Cell Proliferation ; Collagen ; Extracellular Matrix Proteins ; Fungi ; Models, Animal ; Muscle, Smooth ; Myosin Heavy Chains ; Polyglycolic Acid ; Polymers* ; Rupture ; Thrombosis ; Transplants