OBJECTIVETo investigate the influence of some topically used antibiotics (amikacin, gentamicin, chloromycetin and sulfamylon), basic fibroblast growth factor (FGF2) , epithelial growth factor (EGF) and recombinant human growth hormone (rhGH) on the growth of fibroblasts in vitro.

METHODSFibroblasts were cultured and passaged. The cultured cells were then divided into control (routine culture of fibroblasts), amikacin (amikacin in respective dose of 0.021, 0.210, 2.100 mg/L), gentamicin (in respective dose of 5, 50, 500 mg/L) , chloromycetin (in respective dose of 0.01, 0.10, 1.00 mg/L), sulfamylon (in respective dose of 5, 10 g/L), FGF2 (2400 U/ml), EGF (2000 U/ml) and rhGH (0.016, 0.160, 1.600 g/L) groups. After the above agents were added to the culture medium respectively, the proliferation of the cultured fibroblasts was determined with MTT method, and the result was expressed as A (absorption) value. The cell cycle was determined with flow cytometry and the morphology of the cells was observed with inverted microscope.

RESULTS(1) MTT method: The A value of fibroblasts cultured with amikacin, gentamicin, chloromycetin and sulfamylon in various doses was obviously lower than that in control group (0.4553 +/- 0.0217, P < 0.05 or 0.01) , and the A value of sulfamylon group was the lowest in two doses (0.1013 +/- 0.0011 for 5 g/L and 0.0950 +/- 0.0041 for 10 g/L, P < 0.01). On the other hand,the A value in FGF2 and rhGH group(0.016 g/L) was much higher than that in the control (P < 0.05). However,theA value in EGF (both doses) and rhGH groups (0.160, 1.600 g/L) was close to that in control (P > 0.05). (2) Cell cycle determination: The proliferation index (PI) of fibroblasts cultured with amikacin in dose of 0.210 mg/L showed no difference compared to that in control (9.63 +/- 0.45)%, (P > 0.05). But the PI of fibroblasts cultured with FGF2, EGF and rhGF in dose of 0.016 g/L was increased significantly (46.76 +/- 2.33)%, (42.30 +/- 1.41)%, and (13.29 +/- 0.47)%, respectively, (P < 0.05 or 0.01). (3) Histological examination of the cells: The number of fibroblasts in elongated or spindle shape was larger, showing a blur contour but high transparency in control as well as in EGF and rhGH groups (both 0.160 and 1.600 g/L doses groups). The number of cells was lower in amikacin, gentamicin, chloromycetin and sulfamylon groups with sharp but irregular contour and lower transparency, and more granule-like materials and vacuoles in the cytoplasm. The cells in the FGF2 and rhGH (in dose of 0.016 g/L) groups exhibited dense with even distribution and slender or spindle shape and with more mitotic figures but blur contour and high transparency.

CONCLUSIONDifferent kinds of the topically used therapeutic agents for burn wounds exert different influence on the biological characteristics of fibroblasts in vitro. The topically used agents for burn wounds should be carefully selected so that wound healing will be promoted and scar formation inhibited.