The effect of glucose modification of hydroxyapatite nanoparticles on gene delivery.

Surface modification techniques have been employed for the use of biocompatible and bioresorbable hydroxyapatite (HAp) nanoparticles in cell biology and medicine for the delivery of bioactive molecules. We demonstrated the effects of glucose modification of HAp (GlcHAp) on the transfection efficiency in endothelial cells. After preparing homogeneous HAp nanoparticles with a microemulsion technique, the particles with or without glucose modification and plasmid DNA (pDNA) complexes were transfected into endothelial cells. The transfection efficiency of GlcHAp/pDNA was higher than that of HAp/pDNA. To elucidate the mechanism underlying the improvement in the transfection efficiency following glucose modification, the uptake route into the cells and the inhibition of DNA degradation were investigated. GlcHAp/pDNA enhanced the transfection efficiency after interacting with the glucose transporter 1, as observed by the selective inhibitor assay. In addition, GlcHAp/pDNA was more stable than HAp/pDNA in the DNA degradation assay. Our results suggest that the glucose modification could promote the uptake of HAp nanoparticles by cells and protect the internalized DNA; properties essential for non-viral transfection carriers.