Methods: The study included 24 male Wistar albino rats (weight 200 g to 250 g). Groups were defined as A) control (n=6); B) blank polymeric polycaprolactone film (n=6); C) transforming growth factor-b3 containing polymeric polycaprolactone film formulation (n=6); and D) transforming growth factor-b1 neutralizing antibody containing polymeric polycaprolactone film formulation (n=6). Approximately a 0.5 cm vertical incision was performed on all rats between the second and fifth tracheal circles. In group A, tracheal incision was only sutured. In groups B, C and D, tracheal incision was sutured and then blank polymeric polycaprolactone film, transforming growth factor-b3 containing polymeric polycaprolactone film formulation and transforming growth factor-b1 neutralizing antibody containing polymeric polycaprolactone film formulation was placed on the tracheal incision, respectively. The rats were sacrificed 30 days after the surgery. Subsequently, tracheas of rats were examined microscopically. Epithelialization, fibrosis, angiogenesis and inflammation statuses were evaluated histopathologically.

Results: The rats that were observed in terms of respiratory distress, stridor, and malnutrition for 30 days did not show any abnormal events. When the groups were evaluated in terms of inflammation, fibrosis, angiogenesis and epithelization, no statistically significant difference was found (p>0.05).

Conclusion: The active forms of transforming growth factor have a considerably short half-life in the tissue and extracted rapidly. Bioactivity may be maintained and controlled release may be provided with preparations to be developed. Further detailed researches are required to evaluate the effect of transforming growth factor-b3 and transforming growth factor-b1 neutralizing antibody on prevention of granulation tissue after tracheal surgery.