Biological activities in hMSCs transduced with the rAAV/CD-2 system. The rAAV-FLAG-hsox9, rAAV-hTGF-β, and rAAV-lacZ vectors (40 μL each vector, i.e., 8 × 105 transgene copies) were formulated with CD-2 (40 μL), and the resulting rAAV/CD systems (80 μL) were incubated with hMSCs (10,000 cells in 48-well plates; MOI = 80) for up to 21 days. Cell proliferation was examined using the Cell Proliferation Reagent WST-1 (A), glycosaminoglycans using alcian blue staining (light microscopy; magnification ×4; scale bars: 200 μm; all representative data) with spectrophotometric analysis after solubilization (histograms) (B), and the deposition of type-II collagen (C), type-I collagen (D), and type-X collagen (E) using immunocytochemistry (magnification ×20; scale bars: 50 μm; all representative data). rAAV-lacZ/CD-2 and CD-2 lacking rAAV were used as controls. Statistically significant relative to a -/CD-2, b rAAV-lacZ/CD-2, and c rAAV-FLAG-hsox9.