Bioactive sutures for tendon repair: assessment of a method of delivering pluripotential embryonic cells

Purpose Pluripotential embryonic cells may be seeded onto sutures intended for tendon repair. These cells may be influenced to adhere to suture material using adhesion substrates, and furthermore, these cells may remain in culture attached to those sutures. These cell-impregnated sutures may be useful for promoting healing of tendon repairs. Methods Ten-centimeter segments of 4-0 sutures (FiberWire) were coated overnight with 10 μg/mL fibronectin, 10 μg/mL poly-l-lysine, or phosphate-buffered saline. The sutures were placed in dishes and covered with a suspension of C3H10T1/2 cells at concentrations of 1 × 10 6 , 2 × 10 6 , or 4 × 10 6 cells for 24 hours. The sutures were then placed into low adhesion polypropylene tubes with Dulbecco's modified Eagle's medium and 10% fetal bovine serum for 7 days. The presence of viable cells on these sutures was assessed by the colorimetric Alamar blue cell proliferation assay. Spectrophotometry was used to quantify the relative amount of cell proliferation across the experimental groups. The sutures were also visually inspected using phase-contrast light microscopy. Results Our results show that at all seeding densities (1 × 10 6 , 2 × 10 6 , and 4 × 10 6 cells), the suture segments coated with poly-l-lysine and fibronectin showed a significant increase in C3H10T1/2 cell adhesion. Coating the suture with poly-l-lysine increased the adherent cell number to 17% of the initial seeding concentration compared with 2% for the control. Fibronectin coating increased the number of adherent viable cells present to 6.6%. Conclusions Pluripotential embryonic cells may be seeded onto sutures, adhere, and survive in culture. Coating sutures with poly-l-lysine and fibronectin offers significant improvement in retention of viable cells. This technique may be a useful adjunct for future tendon healing studies.