METHODS: The third generation MSCs isolated from mature rabbits by density gradient centrifugation were cultured at different initial concentrations on 0.3 cm x 1.2 cm x 2.0 cm 3-D porous PLGA coated by type I collagen in RPMI 1640 containing 10% fetal calf serum, while cultured on PLGA without type I collagen as control. The cells adhesive and proliferative behavior at 7, 14, and 21 days after inoculation was assessed by determining the incorporation rate of [(3)H]-TdR. In order to examine MSCs differentiation, the expression of osteoblasts marker genes, osteocalcin (OCN), alkaline phosphatase (ALP), osteopontin (OPN) mRNA, were evaluated by reverse transcription-polymerase chain reaction (RTPCR), and further more, the cell morphology at 21 days was also observed by scanning electron microscope (SEM).
RESULTS: Type I collagen promoted cell adhesion on PLGA. The valve was significantly higher than controls. The cells which cultured on PLGA coated with type I collagen showed significantly higher cell proliferation than controls on the 7 th day, the 14th day and 21 th day. Osteoblasts markers, OCN, ALP, OPN mRNA, were all detected on PLGA coated by type I collagen on the 21 th day, but OCN, OPN mRNA could not be found in controls. Spindle and polygonal cells well distributed on the polymer coated by type I collagen while cylindric or round cells in controls.
CONCLUSIONS: Type I collagen is effective in promoting the adhesion, proliferation and differentiation of MSCs on PLGA.Chinese Journal of Traumatology