Calcium phosphate nanoparticles prepared from infusion fluids for stem cell transfection: process optimization and cytotoxicity analysis.

This is the first study to report the use of infusion fluids for particle-mediated gene delivery with DNA-immobilized calcium phosphate (CaP) nanoparticles (NPs). In conventional CaP systems, CaP NPs are fabricated in labile supersaturated CaP solutions which are prepared from chemical reagents. In the present study, we fabricated CaP NPs via coprecipitation in labile supersaturated CaP solutions that were prepared from infusion fluids (even the water used was of injectable quality) instead of chemical reagents and demonstrated their gene delivery capabilities for the hard to transfect pluripotent stem cell (C3H10T1/2) along with the easy to transfect CHO-K1 cell. To achieve a high gene delivery capability by keeping the high safety level of our system intact, we varied the process parameters: coprecipitation temperature and time, along with the Ca and P concentrations of the CaP solution, without using additive agents (e.g. surfactants) other than infusion fluids and plasmids. The optimization of these process parameters led to a higher gene delivery capability compared with that of a commercial CaP system for both types of cells. MTT and protein assays showed that both our system and the commercial CaP system were not cytotoxic to both types of cells. Our CaP system has the advantages of high biological safety (due to injectable source materials), high serum-resistance, and relatively high and controllable gene delivery capability, depending on the process parameters. Thus, the present system warrants consideration for gene delivery applications.