Tendon regeneration with a novel tendon hydrogel: in vitro effects of platelet-rich plasma on rat adipose-derived stem cells.

BACKGROUND: Tendon hydrogel is a promising new injectable substance that has been shown to improve repair strength after tendon injury. This study assesses the capacity of platelet-rich plasma to stimulate proliferation and migration of rat adipose-derived stem cells in tendon hydrogel in vitro.

METHODS: To assess proliferation, adipose-derived stem cells were exposed to plasma, plasma supplemented with growth factors, or platelet-rich plasma in culture medium and tendon hydrogel. To assess migration, adipose-derived stem cells were plated onto tendon hydrogel -coated wells and covered with medium containing plasma, plasma supplemented with growth factors, platelet-rich plasma, or bovine serum albumin. Migration from cell-seeded to cell-free zones was assessed at 12-hour intervals.

RESULTS: Platelet-rich plasma augmented proliferation to a greater extent compared with plasma and plasma supplemented with growth factors (10%: optical density, 1.18 versus 0.75 versus 0.98, respectively). Platelet-rich plasma was superior to plasma in tendon hydrogel (10%: optical density, 1.19 versus 0.85) but did not augment proliferation to the extent that plasma supplemented with growth factors did (10%: optical density, 1.19 versus 1.56). Platelet-rich plasma enhanced the migration of adipose-derived stem cells compared with serum-free medium (bovine serum albumin) (36 hours: platelet-rich plasma, 1.88; plasma, 1.51; plasma plus growth factor, 1.80; bovine serum albumin, 1.43).

CONCLUSIONS: Tendon healing is mediated by migration of cells to the injured area and cellular proliferation at that site. Tendon hydrogel supplemented with platelet-rich plasma stimulates these processes. Future studies will evaluate this combination's ability to stimulate healing in chronic tendon injuries in vivo.