Nanogel-inorganic hybrid: Synthesis of polysaccharide-calcium phosphate nanomaterials

POLY 422

Setsuko Yamane, Ayae Sugawara, and Kazunari Akiyoshi. Department of Organic Materials, Institute of Biomaterials & Bioengineering, Tokyo Medical & Dental University, 2-3-10, Kanda-surugadai, Chiyoda-ku, Tokyo, 101-0062, Japan
The polymer-inorganic hybrids have attracted a great interest in the field of biotechnology. We synthesized organic-inorganic hybrid nanoparticles consisting of nanogel of cholesterol-bearing pullulan (CHP) and calcium phosphate. Two methods were developed to prepare nanogel-calcium phosphate nanoparticles by using alternate ion addition method and pH-gradient method. Amorphous calcium phosphate (ACP) nanoparticles ca. 30 nm in diameter were prepared by alternate addition of calcium ions and phosphate ions to CHP nanogel suspension at pH 11 and at 25 ºC. Nanogel-ACP nanopaticles were also prepared by pH-gradient method based on the fact that calcium phosphates are more insoluble at basic pH. Well-dispersed nanoparticles of ACP were formed from the solution in the presence of CHP nanogels. These results suggest that CHP nanogels act as templates for calcium phosphate formation. The new hybrid nanoparticles have potential applications in the fields of tissue engineering and drug delivery systems.