| The objective was to determine whether certain mechanical stresses can differentiate bone marrow-derived hMSCs toward an osteogenic lineage. hMSCs were isolated from donor bone marrow (N=2), cultured, and encapsulated in Polyethylene glycol (PEG) at a density of 1 x 106 cells/ml. Microcompressive forces at 10kPa were applied to the experimental PEG at 0.5 Hz (N=36) or 3.0Hz (N=36) for 1 hr/day for 8 days, followed by 2-wk incubation. Control (N=72), PEG/hMSCs were incubated for the same duration. Half of the samples were sectioned and stained for H&E and safranin-o, whereas the other half were quantified for osteogenic and chondrogenic markers. hMSCs in PEG stimulated at a frequency of 3.0Hz demonstrated a statistically significant difference between the control and 0.5Hz groups for the osteogenic markers. There was no difference between the chondrogenic between all three groups. These data demonstrate that hMSCs encapsulated in PEG stimulated with 3.0Hz demonstrated differentiation toward an osteogenic lineage. |
