The mechanical and biological properties of an injectable calcium phosphate cement-fibrin glue composite for bone regeneration.

Calcium phosphate cement (CPC) that can be injected to form a scaffold in situ has promise for the repair of bone defects. However, its low-strength limits the CPC to non-stress-bearing repairs. Fibrin glue (FG) with good sticking property and biocompatibility is possible used to reinforce the CPC. The objective of this study was to investigate the effects of FG on the mechanical and biological properties of CPC in an injectable CPC-FG composite. The initial setting time of this CPC-FG was delayed compared with the CPC control at different powder/liquid (P/L) mass ratio (p > 0.05). At a P/L of 5, the strength was (38.41 +/- 4.32) MPa for the CPC-FG, much higher than (27.42 +/- 2.85) MPa for the CPC alone (p < 0.05). SEM showed bone marrow stromal cells (BMSCs) with healthy spreading and anchored on the CPC-FG composite. After 14 days, the alkaline phosphatase (ALP) activity was (538 +/- 33) for the BMSCs on the CPC-FG and (517 +/- 27) for the BMSCs on the CPC alone. Both ALPs were higher than the baseline ALP (93 +/- 10) for the undifferentiated BMSCs (p < 0.05). The results demonstrate that this stronger CPC-FG scaffold may be useful for stem cell-based bone regeneration in moderate load-bearing orthopedic applications.