Ca-Mg phosphate nano-crystals for high efficiency gene delivery and expression in mammalian cells

Co-precipitation of DNA with calcium phosphate which is based on hydroxyapatite, is one of the most commonly used non-viral vectors. Although inefficiency in particle-mediated uptake of DNA by the cells has been considered as a major barrier of low transgene expression in vitro and in vivo, an effective way of manipulating particle growth kinetics at the molecular level has not been focused so far, which could overcome the hurdle dramatically. Here, we report on the development of a highly efficient synthetic device for gene delivery and expression into mammalian cells, based on controllable growth of nano-apatite particles. Mg²⁺ Incorporation Into the apatite particles caused significant inhibition of particle-growth, resulting in retention of nano-sized particles which could contribute remarkably to the cellular uptake of DNA and its subsequent expression (10 to 100-fold) compared with classical calcium phosphate co-precipitation, one of the most widely used transfection methods.