DNA-lipid-apatite composite layers enhance gene expression of mesenchymal stem cells.

DNA-apatite composite layer (D-Ap layer) and DNA-lipid-apatite composite layer (DLp-Ap layer) were prepared on ceramic hydroxyapatite disk and scaffold using supersaturated calcium phosphate solutions supplemented with 0.5-5 μg/mL plasmid and 0-10 μL/mL lipid transfection reagent FuGENE®. Both in vitro and in vivo studies were carried out using mesenchymal stem cells (MSCs) and two kinds of gene (luciferase and bone morphogenetic protein (BMP)-2) for demonstrating potential application of the gene transfer system using the D-Ap and DLp-Ap layers in bone tissue engineering. In the in vitro study using luciferase gene, the DLp-Ap layers showed 1-2 orders of magnitudes higher gene transfer efficiency to MSCs than the D-Ap layer. In the in vivo study using BMP-2 gene, DLp-Ap layer slightly increased BMP-2 protein concentration than D-Ap layer, thereby enhancing their osteogenic differentiation than D-Ap layer. The present gene transfer system using the DLp-Ap layers, with the advantages of good biocompatibility, bone-bonding ability, and efficacy in in vitro and in vivo gene transfer to MSCs, would be useful in bone tissue engineering.