[Effects of insulin on the growth factor secreting function of adipose-derived stem cells]

OBJECTIVE

To study the effect of insulin in different concentrations on secretion function of growth factors of adipose-derived stem cells (ADSCs).

METHODS

ADSCs were isolated from human abdominal adipose tissue and cultured. The immunophenotype and adipose induced-differentiation were identified, and the third generation cells were collected. The collected cells were assigned to 1 x 10(-8), 1 x 10(-7), 1 x 10(-6) mol/L insulin groups according to the concentration of added insulin. When cells grew into 70% confluence in conventional medium, ADSCs were cultured further in serum-free DMEM containing insulin in different concentrations for 3 days. ADSCs cultured in medium without insulin were used as control group. Secretion amount of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) of ADSCs were determined by enzyme-linked immunosorbent assay. The effects of the supernatant fluid of ADSCs' nutrient solution on the proliferation and collagen synthesis of the cultured fibroblast were detected by MTT chromatometry and hydroxyproline chromatometry.

RESULTS

The secretion amounts of VEGF and HGF of ADSCs in 1 x 10(-8) and 1 x 10(-7) mol/L insulin groups [(471 +/- 41, 762 +/- 66 ng/L), (643 +/- 64, 930 +/- 67 ng/L), respectively] were significantly higher as compared with those in control group (286 +/- 47, 577 +/- 84 ng/L) (P < 0.05 or P < 0.01). No change occurred in the secretion amount of VEGF and HGF of ADSCs in 1 x l0(-6) mol/L insulin group (P > 0.05). The supernatant fluid of ADSCs' nutrient medium of 1 x 10(-8), 1 x 10(-7) mol/L insulin groups showed obvious stimulative effect on the proliferation and collagen synthesis of fibroblasts, and it was most obvious in the 1 x 10(-7) mol/L group (P < 0.05 or P < 0.01).

CONCLUSIONS

Insulin in the concentrations of 1 x 10(-8) and 1 x 10(-7) mol/L can notably promote ADSCs' function of secreting VEGF and HGF.

[Application of lavation and drainage with continuous negative pressure in the debridement of diabetic foot complicated by plantar abscess]

OBJECTIVE

To investigate the feasibility of debridement at early stage by combining lavation and drainage under continuous negative pressure in the limb salvage surgery of patients suffering from diabetic foot complicated by plantar abscess.

METHODS

Ten patients suffering from diabetic foot (10 feet affected) combined with plantar abscess were involved. After being debrided, wounds of patients were lavaged and drained for 7 - 14 ds under continuous negative pressure through a detained stomach tube. Suction under negative pressure continued for 3 - 5 ds after lavation, and then drainage tube was removed. Stitches on wound were removed about 3 weeks after surgery. The condition of the wounds was observed.

RESULTS

After above-mentioned treatment, local inflammatory response of patients was obviously ameliorated, and the wounds healed with satisfactory preservation of function and shape of the feet.

CONCLUSIONS

Debridement combined with local lavation and drainage under continuous negative pressure is satisfactory for the treatment of diabetic foot complicated by plantar abscess, and it can preserve the length of the affected limb.