126 Ann. N.Y. Acad. Sci. 961: 126–129 (2002). © 2002 New York Academy of Sciences. The Efficacy of Bone Marrow Stromal Cell-Seeded Knitted PLGA Fiber Scaffold for Achilles Tendon Repair HONG WEI OUYANG, a JAMES C.H. GOH, a XIU MEI MO, b SWEE HIN TEOH, b AND ENG HIN LEE a a Department of Orthopaedic Surgery, National University of Singapore, Singapore b Laboratory of Biomedical Engineering, National University of Singapore, Singapore INTRODUCTION Tendons are frequently targets of injury in sports and aging trauma. Significant dysfunction and disability can result from suboptimal healing of tendon injuries. It is generally thought that tendons have some self-healing ability, but in cases where tendons are missing or the wound sites are too large to allow for reapposition of the ends, tendon replacement is necessary. 1 Various bioabsorbable materials have been used for Achilles regeneration; 2 however, no published data that we are aware of has addressed the use of D,L-lactide-co-glycolide (PLGA, 10:90) fibers or knitted struc- ture to deliver bone marrow stromal cells for tendon repair. This study was conduct- ed to evaluate the effect of marrow-stromal-cell (bMSC)-seeded knitted PLGA scaffold for Achilles tendon repair in a rabbit model. MATERIALS AND METHODS In 32 legs of 16 adult female New Zealand White rabbits, a tendon defect was cre- ated according to the method used by Young et al. 3 In brief, from a lateral approach, the gastrocnemius tendon was separated from the plantaris and soleus tendons and a 1-cm-long gap defect was created in the midsubstance of the gastrocnemius tendon. In group I (12 legs), a knitted PLGA graft was sutured to the ends of tendon and seeded with 1 × 10 7 bone marrow stromal cells in 0.3 mL fibrin glue; group II (12 legs) was treated with a knitted PLGA scaffold infused with 0.3 mL fibrin glue; and group III (8 legs) was treated with a single suture as control. In all legs, the tension on the repaired tendon was returned to approximately normal. The rabbits were al- lowed to move freely in the cages postoperatively throughout the test period. Speci- mens were harvested at 2, 4, 8, and 12 weeks for macroscopic, histological, and immunohistochemical examination. Author for correspondence: Associate Professor J.C.H. Goh, Orthopaedic Diagnostic Center, Level 3, Department of Orthopaedic Surgery, National University of Singapore, 5 Lower Kent Ridge Road, Singapore 119074. Voice: 0065-7724423; fax: 0065-7744082. dosgohj@nus.edu.sg