Introduction: Flexor tendon repair in Zone II is complicated by adhesions to the surrounding sheath which can significantly impair hand function. Transforming growth factor beta is a cytokine with numerous biologic activities related to wound healing. We examined the effects of TGF-beta 1,2 and 3 on tendon cell proliferation and collagen production.

Methods: The flexor tendon and tendon sheath were excised from rabbit forepaws. Three cell lines—tendon sheath fibroblasts, epitenon and endotenon tenocytes were isolated and cultured. Cell culture media was supplemented with 1 ng/ml or 5 ng/ml of TGF-beta 1, 2, or 3. Cell number and collagen I and III production were measured and compared to unsupplemented control cultures.

Results: All three cell lines produced collagen I and III. The addition of TGF-beta to cell culture media resulted in a decrease in cell number in all three lines. However, there was a significant increase (p<0.05) in collagen I and III production with the addition of all three TGF-beta isoforms. For sheath and endotenon cell lines, the most significant effects of TGF-beta were observed with the addition of TGF-beta 1. In the epitenon cell lines, the trend of increased collagen production was similar in all three TGF-beta subtypes

Conclusions: The addition of TGF-beta to tendon cell culture media results in a significant increase in collagen production. TGF-beta, which has been shown to have a pivotal role in the wound healing process in a variety of tissues, likely has a critical role in flexor tendon wound healing. Modulation of TGF-beta expression may provide a means to reduce adhesion formation.