Different adhesion rate of sheep BMSCs on copolymers of 3-hydroxybutyrate and 3-hydroxyvalerate before and after photografting modification in vitro]

To evaluate the biocompatibility of the sheep BMSCs cultured on the surface of photografting modified copolymers of 3-hydroxybutyrate and 3-hydroxyvalerate (PHBV).BMSCs were isolated from bone marrow of the posterior iliac crest of a 6-month old sheep by whole marrow adherent culture method. The 3rd passage BMSCs were seeded onto modified PHBV and conventional PHBV films, or three-dimension scaffolds. Cell-adhesion rates were calculated by hemocytometer at 1, 2 and 6 hours after seeded. Cell morphology was examined by scanning electron microscope when the BMSCs were cultured for 3 days, 1 week and 3 weeks. Cell cycle was analyzed by flow cytometry at 5 days after seeded. The content of protein in BMSCs was determined by BCA assay and the content of DNA was quantified by Hoechst 33258 assay at 4, 8 and 12 days after seeded.At 1 hour after seeded, cell-adhesion rate on modified PHBV films (52.7% +/- 6.0%) was significantly higher than that of conventional PHBV films (37.5% +/- 5.3%) (P < 0.05); At 2 and 6 hours after seeded, cell-adhesion rate of modified PHBV films was similar to that of PHBV films (P > 0.05). The surface of modified PHBV film was rougher. In the early culture stage, more cells adhered to modified PHBV and the cells displayed much greater spreading morphology. Furthermore, ECM on modified PHBV were richer. There were no significant differences between the trial team and the control on the cell cycle and the content of DNA and protein of BMSCs (P > 0.05).Photografting modification on PHBV can promote BMSCs' adhesion and enhance their biocompatibility.