[Effects of the surface of PLGA-(ASP-PEG) modified with RGD and K16-containing peptide on the adhesion and differentiation of bone marrow stromal cells].

In this experimental study, the RGD-containing peptide was used to modify the surface of biomimetic PLGA-(ASP-PEG) matrix, and bone marrow stromal cells (BMSCs) were seeded onto these modified surfaces for three weeks. The effects of modified surfaces of matrix on the adhesion, proliferation and differentiation of BMSCs were explored. BMSCs were harvested from whole bone marrow of Sprague-Dawley (SD) rats in vitro, then were seeded onto peptide surface-modified matrix (Experiment group, EG) and matrices without modification (Control group, CG) respectively for three weeks. The number of adhesive cells was counted by using precipitation method after 4 h and 12 h incubation; the cells cytoskeletons were stained with FITC-conjugated phalloidin after 24h incubation; the cell density was investigated after 1 d, 2 d and 3 d of incubation; ALP activity of BMSCs was measured after 7 d, 14 d and 21 d of incubation with osteogenic medium. The cells from bone marrow were BMSCs and their purity was beyond 90% using flow cytometry (FCM) analysis. Sulphur binding energy in EG was shown by XPS to be 164 eV. BMSCs adhered on peptide surface-modified matrix were observed with SEM. Cell adhesion efficiency and quality in EG was better than that in CG, and cell cytoskeleton was more robust in EG. ALP activity was higher in EG than in CG. Peptide surface-modified PLGA-(ASP-PEG) was noted to have good compatibility with BMSCs and to promote cell adhesion and differentiation.