Synthesis of nanosized porous hydroxyapatite granules in hydrogel by electrophoresis

Nanosized porous hydroxyapatite (HA) granules are expected to be useful as DNA and drug carriers for cells. We attempted to synthesize nanosized HA granules in an agarose gel by electrophoresis of calcium and phosphate ions. Wells were prepared on an agarose gel, and a CaCl2 solution was placed in the wells on the positive side and a Na2HPO4 solution was placed in the wells on the negative side. After a potential was applied, white precipitates appeared in the gel. The precipitates were calcium-deficient HA granules of approximately 300–600 nm in diameter. These granules were composed of fiber-like particles and had a porous structure. The diameters of the granules were decreased by an increase in the gel concentration. Hence, we successfully synthesized nanosized porous HA granules to be used as DNA and drug carriers.