Sustained local application of low-dose epidermal growth factor on steroid-inhibited colonic wound healing

The effects of locally administered low-dose epidermal growth factor in a steroid-inhibited wound healing were investigated in a rat model.

Long-acting release of epidermal growth factor was enabled using microspheres embedded in gelatin sponge. Study groups consisted of 60 rats with 10 in each: colonic anastomosis only (C), plus pure gelatin sponge (CG), plus epidermal growth factor loaded sponge (CE), colonic anastomosis and steroid (S), plus gelatine sponge (SG), and plus epidermal growth factor-loaded gelatine sponge (SE) groups. Bursting pressure and wound hydroxy-proline content were measured. Bursting sites were recorded. Collagen deposits, inflammation, and foreign body reactions were evaluated.

Bursting pressure and hydroxy-proline contents were found lowest in the S and highest in the CE groups (P <.01). There was almost no difference between C and SE groups. Bursts were encountered in peri-anastomotic normal colon sites in the nonsteroid-treated C, CG, and CE groups. They were noted overwhelmingly at the anastomosis in steroid-inhibited S, SG, and SE groups. Histopathology results showed a standstill at the inflammatory phase of healing in S and SG groups. The best healing was observed in the CE group. Degree of collagen accumulation was well correlated with bursting pressure and hydroxy-proline content data with a negligible foreign body reaction to gelatine sponge.

Continuous local epidermal growth factor administration by microspheres in gelatin increases wound collagen and further enhances healing in colonic anastomoses even with steroid inhibition.