OBJECTIVETo isolate and culture mesenchymal stem cells ( MSC) from different sources and to investigate the chemotactic effects of burn rat serum on MSC derived from different sources.

METHODSSeventy-two Wistar rats were randomly divided into burn( n = 36, with 30% TBSA full-thickness burns on the back) and sham burn (n = 36, without burns) groups. Bone marrow and peripheral blood of the rats in both groups were collected to isolate and culture MSC. Ratio of MSC, growth speed and cell morphology were observed with inverted microscope. Effects of different serum ( fetal bovine serum, normal rat serum and burn rat serum) on chemotaxis of MSC derived from different sources and their migration ability were subsequently examined with a transwell system. Results MSC were obtained from bone marrow of the rats in both groups. MSC were successfully obtained from bone marrow of all burn rats(100% , P <0.05) , but only from peripheral blood of 7 burn rat(58% ) , and no MSCs were obtained from peripheral blood of 12 rats in sham group( P <0.05). There was small amount of adherent cells 24 hrs after culture, and fusiform shaped adherent cells were sporadically observed in scattered distribution 2-3 days later with inverted microscope. There was no obvious difference in the cell morphology between the 2 groups. In the sham group, the number of MSC migrating to the lower surface of transwell after burn serum treatment [ (94 Il ) cells/ high power field] was significantly greater than that after the treatment with normal rat serum and fetal bovine serum [ (37 +/- 6) , (38 +/- 11) cells/high power field , P <0.01 ] , while no difference in migration ability was found after normal serum treatment compared with that after fetal bovine serum treatment ( P >0. 05). The migration rate of MSCs which were derived from bone marrow in sham group was obviously lower than those derived from bone marrow and peripheral blood from burn rats ( P <0. 05 or 0. 01). Though some difference of the migration ability existed between MSC derived from bone marrow and peripheral blood, there was no statistically significant difference ( P >0. 05).

CONCLUSIONMSC can be isolated and cultured from bone marrow and peripheral blood of burn rat, but not from peripheral blood of normal rat. Burn rat serum has a stronger chemotactic effect on MSC. Moreover, the migration ability of MSC derived from burn rat is stronger than that of MSC derived from normal rat.