Buffer solution can control the porosity of DNA‐chitosan complexes

Abstract

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.

Drug Binding and Releasing Characteristics of DNA/Lipid/PLGA Film

“…Moreover, a circular dichroism study confirmed that DNA in the films maintained the native doublestrand structure. On the other hand, Fukushima et al 5) measured the amount of DH bound to DNA-chitosan complexes immersed in DH aqueous solution for 50 hours. They reported that one molecule of DH was bound to 4.5-6.2 bps of DNA in the complexes, and that the complexes maintained a double-helical structure similar to that of native DNA.…”

“…These reaction ratios were slightly low in comparison with that of native DNA. In a study on DNA/chitosan complexes, Fukushima et al 5) reported that lower intercalation and groove binding of DH were due to steric hindrance by chitosan. Similarly for Iwata et al 16) , their study on DNA/alginic acid films revealed that DNA bps/EB ratio was lower than that of native DNA.…”

“…In recent years, strategies to apply deoxyribonucleic acid (DNA) as a biomaterial in tissue engineering have been developed and carried out [1][2][3][4][5] . Such immense interest in DNA has arisen because of the latter' s favorable properties as a biomaterial [6][7][8] .…”

“…Moreover, the DNA/lipid films could form intercalation complexes with ethidium bromide (EB) 13) . In another study 5,14) , water-insoluble DNA/chitosan complexes were prepared from the reaction between DNA and chitosan as scaffolds for tissues engineering. DNA/chitosan complexes could easily bind daunorubicin hydrochloride (DH), an anticancer drug itself and an intercalator like EB, in aqueous solutions.…”

“…DNA/chitosan complexes could easily bind daunorubicin hydrochloride (DH), an anticancer drug itself and an intercalator like EB, in aqueous solutions. Indeed, one molecule of DH was bound to 4.5-6.5 base pairs (bps) of DNA in these complexes 5) . These binding ratios were close to an exclusion number (bps/drug) of 3.7 for the binding of DH by native salmon DNA 15) .…”