Buffer solution can control the porosity of DNA-chitosan complexes

The current studies examine the pore properties and biological effects of DNA‐chitosan complexes, which may be useful as scaffolds for tissue engineering. The porosity of the DNA‐chitosan complexes was controlled by rinsing them with several different pH 7.2 buffer solutions, including phosphate‐buffered saline (PBS), Tris‐HCl, boric acid, and N‐(2‐hydroxyethyl)piperazine‐N′‐(2‐ethanesufonic acid) (HEPES). Rinsing with PBS resulted in 84% porosity, whereas rinsing with Tris‐HCl produced 94% porosity. It was further found that daunorubicin hydrochloride complex intercalated with and bound to the groove of the DNA‐chitosan complexes, indicating that DNA in the complexes maintains its double‐stranded helical structure. The DNA‐chitosan complexes were not toxic to MG‐63 osteoblast‐like cells and caused only a mild tissue response when implanted subcutaneously in the backs of rats. These results suggest that buffer‐rinsed DNA‐chitosan complexes may be useful as a scaffold material in tissue engineering. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006